JP2006243707A - Toner supply device and image forming apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner supply device which surely carries toner by piping for toner carrying so as to secure high reliability of toner supply performance by a mohno-pump even when being used for a toner bottle which discharges toner by rotation of a vessel, and also to provide an image forming apparatus using the device. <P>SOLUTION: The toner supply device includes; a toner bottle 2 with a spiral rib for discharging toner to the outside, provided on the inside wall; a driving means 3 for rotating the toner bottle; a powder pump 22 for carrying the toner discharged from the toner bottle 2 toward a developing means for image formation; a storage part 1a which is disposed between the toner bottle 2 and the powder pump 22 and stores the toner discharged from the toner bottle 2; and piping 33 which is disposed between the powder pump 22 and the storage part 1a and functions as a carrying path for carrying the toner to the powder pump. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner replenishing device and an image forming apparatus using the toner replenishing device, and in particular, when toner discharged by rotating a toner bottle having a spiral rib on an inner wall is conveyed by a pipe, reliable toner conveyance is possible. The present invention relates to a toner replenishing device capable of ensuring high reliability with respect to toner replenishment performance by a single-shaft eccentric screw pump (Mono pump) and an image forming apparatus using the same.

  In recent years, in an image forming apparatus such as a copying machine, it has become common to use a single-shaft eccentric screw pump for supplying toner to a developing device and a developing hopper, and toner is supplied to supply toner from outside the device. Some are configured to set a filled cartridge. This toner replenishment system is a system in which a uniaxial eccentric screw pump is disposed on the developer side, a tube is disposed on the toner cartridge side, and the rotor of the uniaxial eccentric screw pump is driven to directly suck the toner in the cartridge. is there. This is due to reasons such as simplification of the apparatus and space saving in addition to handling of the cartridge after use.

  FIG. 10 shows an example of a toner replenishing device using a cartridge 21 and a uniaxial eccentric screw pump 22. When the developing hopper toner end sensor 25 attached to the developing hopper 24 having the screw 23 detects the absence of toner in the hopper, the control unit operates the pump driving clutch 26 via the driving gears 27 and 28 and the rotor shaft 29. The rotor 31 rotates within the stator 30, and a suction force is generated in the space between the stator 30 and the rotor 31 to start toner supply from the cartridge 21. Further, the toner is supplied to the developing unit 32 by driving the screw 23. The toner filled in the cartridge 21 is conveyed into the developing hopper 24 through the tube 33 as a pipe by the suction force of the uniaxial eccentric screw pump 22. In this configuration, the air pump 34 is provided in the nozzle portion 35. However, depending on the type of cartridge, the toner can be conveyed even if the air pump 34 is omitted.

In addition to the above-described cartridge, a toner bottle having an inner wall provided with a spiral rib is known as a replacement container filled with toner. This is configured to replenish the toner by utilizing the fact that the set toner bottle is automatically rotated and the inside toner is discharged out of the bottle by the effect of the spiral rib. (For example, refer to Patent Document 1).
Here, comparing the case where a toner cartridge is used with the case where a toner bottle is used, the cartridge is not suitable for increasing the capacity, and the container is replaceable, the amount of toner remaining in the container when toner out is detected, and the toner supply. Inferior in reliability (reliability).

JP-A-6-214460

  However, in the case of a toner bottle, because the structure that rotates the bottle, the toner cannot be directly drawn from the toner bottle by piping such as a tube, so that there is a problem that free design using piping as in the case of a cartridge cannot be performed. It was. In particular, there has been no structure that provides high reliability with respect to the toner replenishment performance of the single-shaft eccentric screw pump.

  Therefore, the present invention has been made in consideration of the above-described circumstances, and even when a toner bottle that discharges toner by rotating a container is used, it can be reliably conveyed by a toner conveying pipe and is uniaxial. It is an object of the present invention to provide a toner replenishing device capable of ensuring high reliability with respect to toner replenishment performance by an eccentric screw pump and an image forming apparatus using the same.

  According to the first aspect of the present invention, there is provided a toner replenishing device for supplying toner for forming an image on a transfer material, wherein the inner wall is provided with a spiral rib for rotating the inner toner to the outside by rotating. A toner bottle, a driving means for rotating the toner bottle, a powder pump for conveying the toner discharged from the toner bottle to the developing means side for image formation, and between the toner bottle and the powder pump. And a storage part for storing the toner discharged from the toner bottle, and a pipe which is provided between the powder pump and the storage part and functions as a transport path for transporting the toner to the powder pump. It is provided with.

  According to a second aspect of the present invention, in the toner replenishing device according to the first aspect, the toner replenishing device further includes a toner end sensor for detecting the toner amount in order to keep the toner amount in the storage portion constant, and the toner end sensor A control unit is provided that controls toner supply to the storage unit based on the detected presence or absence of toner.

  According to a third aspect of the present invention, in the toner replenishing device according to the second aspect of the present invention, the toner replenishing device further includes a cleaning unit that cleans a detection surface of the toner end sensor, and the control unit synchronizes with the start of operation of the powder pump. And the cleaning means is stopped in synchronism when both the operation of the powder pump and the toner replenishment operation to the reservoir are stopped.

  According to a fourth aspect of the present invention, in the toner replenishing device according to the second or third aspect of the present invention, stirring means for stirring the toner is further provided in the storage section, and the control section is synchronized with the start of operation of the powder pump. A toner replenishing device, wherein the agitation unit is driven to stop the agitation unit in synchronization with the operation stop of the powder pump.

  According to a fifth aspect of the present invention, in the toner replenishing device according to the second aspect of the present invention, the toner replenishing device further includes a cleaning unit that cleans the detection surface of the toner end sensor, and a stirring unit that stirs the toner in the storage unit. The control unit operates the cleaning unit and the agitation unit prior to the operation of the powder pump, then operates the powder pump after a predetermined time, and operates the cleaning unit and the agitation during the operation of the powder pump. The operation of the means is continued.

  The invention according to claim 6 is the toner replenishing device according to claim 2, further comprising a cleaning means for cleaning the detection surface of the toner end sensor, and an agitation means for agitating the toner in the reservoir, The control unit operates the cleaning unit and the stirring unit for a predetermined time at the start of operation after the apparatus has been stopped for a predetermined time or longer.

  A seventh aspect of the invention is characterized in that a polymerized toner is used in the toner replenishing device according to any one of the first to sixth aspects.

  An eighth aspect of the invention is an image forming apparatus including the toner replenishing device according to any one of the first to seventh aspects.

  According to the present invention, the toner can be stored in the storage portion to which one end side of the toner conveying pipe is connected, so that the toner can easily enter the pipe and the suction by the powder pump through the pipe. Even when a toner bottle that discharges toner by rotating the container is used, it is possible to reliably convey the toner by piping, and to ensure high reliability with respect to the toner replenishment performance by the powder pump. Further, even if a pipe is used for toner conveyance, no problem in conveyance occurs, so that the degree of freedom in designing the toner conveyance layout when a toner bottle is employed is improved.

  Further, the toner amount in the storage unit can be confirmed by the toner end sensor, and the driving unit can be controlled based on the output signal of the toner end sensor to keep the toner in the storage unit constant. As a result, the driving efficiency can be improved by maximizing the toner replenishment capability of the powder pump.

  In addition, a cleaning means for cleaning the toner detection surface of the toner end sensor is provided, and the cleaning operation is started in synchronization with the operation start of the powder pump, and is synchronized when both the suction operation and the toner replenishment operation are stopped. Therefore, it is possible to improve the reliability of the toner presence / absence detection function in the storage portion by removing the toner and foreign matter adhering to the toner detection surface and improving the efficiency of the cleaning operation. By shortening, the failure rate of the cleaning means and the toner end sensor can be reduced, and the life of the bearing and the like can be improved.

  In addition, since the agitation means that is controlled in synchronism with the suction operation of the powder pump is provided, it is possible to prevent the formation of a cavity due to toner replenishment or suction of the powder pump and to limit the operation time of the agitation means due to excessive agitation. It is possible to reduce the toner bulk density reduction, eliminate the erroneous detection of the presence or absence of toner, reduce the driving time by improving the efficiency of the stirring operation, reduce the failure rate of the stirring means, and improve the life of the bearing and the like.

The best mode for carrying out the present invention will be described below in detail with reference to the drawings.
The characteristic configuration of the present invention will be described with reference to FIG. 1. The toner replenishing device of the present invention is a toner bottle having spiral ribs on the inner wall for discharging toner inside to the outside by rotating. 2, a driving unit 3 for rotating the toner bottle 2, and a single shaft for conveying the toner discharged from the toner bottle discharge port 2 a to the developing unit (developing unit) for image formation provided in the image forming apparatus. A powder pump composed of an eccentric screw pump (Mono pump), a storage unit 1a disposed between the toner bottle and the powder pump, and storing the toner discharged from the toner bottle, and between the powder pump and the storage unit 1a And a pipe (tube) functioning as a conveyance path for conveying the toner to the powder pump.
Each component is controlled by a control unit (not shown).

  FIG. 1 is a cross-sectional view of a main part of a toner replenishing device (Embodiment 1) which is the best mode for carrying out the present invention. The toner supply device according to the first exemplary embodiment temporarily holds a plastic toner bottle 2 filled with toner, a driving unit (motor) 3 that rotates the toner bottle 2, and toner discharged from the toner bottle 2. A sub hopper 1a serving as a storage unit, a uniaxial eccentric screw pump serving as a powder pump that provides a conveying force for conveying toner to a necessary portion, a uniaxial eccentric screw pump, and the sub hopper 1a. It has a tube as a pipe functioning as a toner conveyance path to the eccentric screw pump. Since the tube and the uniaxial eccentric screw pump have the same basic configuration as that shown in the description of the prior art, the tube and the uniaxial eccentric screw pump are omitted in the drawings shown here.

  As shown in FIG. 1, the toner replenishing device has a front end portion in a horizontal orientation in an insertion hole provided in an upper side surface of a housing 1 having a sub hopper 1 a in which toner is discharged and stored. The toner bottle 2 is rotatably supported in the fitted state. The inner wall of the toner bottle 2 is provided with a plurality of spiral ribs (not shown) for discharging the toner filled therein to the outside, and the toner bottle 2 is driven by the driving force applied from the driving means 3. As the toner rotates in the circumferential direction, the toner inside is discharged from the discharge port 2a at the front end of the bottle. The driving unit 3 includes a motor 3a as a driving source and gears 3b, 3c, and 3d that transmit driving force, and the operation of the driving unit 3 is controlled by a control unit (not shown).

  A discharge port opening / closing means 4 is provided on the wall of the housing 1 facing the discharge port 2a. The discharge port opening / closing means 4 includes a convex portion 4a that fits into the discharge port 2a and serves as a lid of the discharge port 2a, a motor 4b that applies driving force to the convex portion 4a, and a worm 4c that transmits the driving force of the motor 4b, The worm wheel 4d and the rack 4e are configured, and the rack 4e and the convex portion 4a are slid laterally by the motor 4b to open and close the discharge port 2a. The operation of the motor 4b is controlled by a control unit (not shown).

  A sub hopper 1 a that temporarily stores the toner discharged from the toner bottle 2 and dropped is formed at the bottom of the housing 1. Since the toner in the sub hopper 1a is conveyed through the inside of the tube, the tip 1a 'of the sub hopper 1a is configured such that the tube can be connected as shown in FIG. The toner conveyed through the tube by the uniaxial eccentric screw pump is supplied to a place where toner is required, such as a developing unit that performs image formation.

  FIG. 2 is a flowchart showing the control operation of the uniaxial eccentric screw pump. This flowchart is an example showing the operation when the toner supply device of the present invention is provided in an image forming apparatus such as a copying machine. In the control operation of the uniaxial eccentric screw pump in FIG. 2, when an image forming operation (copying) is started, a toner end sensor (not shown) in a developing hopper that a developing unit for forming an image has for supplying toner therein. Is acquired (step S1). In step S2, the presence or absence of toner is confirmed. If there is toner, the process returns to step S1, and if there is no toner, the uniaxial eccentric screw pump is driven (step S3), and the process returns to step S1 again.

  Therefore, in the toner replenishing device according to the first exemplary embodiment, toner can be stored in the sub hopper 1a to which one end of a toner conveying pipe (tube) is connected, so that the toner easily enters the tube and is uniaxially eccentric. Even if a toner bottle that discharges toner by rotating the container is easy, suction through the tube by the screw pump is possible, and reliable supply by the tube is possible, and toner replenishment performance by the single-shaft eccentric screw pump High reliability can be secured. Further, since there is no problem in conveyance even when a tube is used, the degree of freedom in designing the toner conveyance layout when a toner bottle is employed is improved.

  Next, a toner replenishing device of Example 2 will be described. Note that a description of the same parts as those in the first embodiment will be omitted. FIG. 3 is a cross-sectional view of a main part of the toner supply device according to the second exemplary embodiment. In this example, as shown in the figure, a toner end sensor 5 for detecting the presence or absence of toner is attached to the upper wall surface of the sub hopper 1a. Since the height from the bottom of the sub hopper 1a to the toner end sensor 5 is a toner storage space, the mounting position of the toner end sensor 5 is determined according to how much toner is stored in the sub hopper 1a.

  FIG. 4 is a flowchart showing a toner replenishment control operation for the sub hopper 1a. This flowchart is an example of the operation when the toner supply device is provided in an image forming apparatus such as a copying machine. In the toner replenishment control operation by the toner bottle 2 in FIG. 4, when the image forming operation (copy) is started, information of the toner end sensor 5 in the sub hopper 1a is acquired (step S11). In step S12, the presence or absence of toner is confirmed. If there is toner, the process returns to step S11. If there is no toner, the driving means 3 is driven to rotate the toner bottle 2 to replenish the toner (step S13). Return to step S11.

  Therefore, in the toner replenishing device according to the second embodiment, the toner amount in the sub hopper 1a is confirmed by the toner end sensor 5, and the operation of the driving unit 3 is controlled based on the output signal of the toner end sensor 5 to remove the toner in the sub hopper 1a. Can be kept constant. As a result, the driving efficiency can be improved by making full use of the toner replenishment capability of the uniaxial eccentric screw pump.

  Next, a toner replenishing device of Example 3 will be described. Note that a description of the same parts as those in the first embodiment will be omitted. FIG. 5 is a cross-sectional view of a main part of the toner supply device of Embodiment 3. In this example, as shown in the figure, a cleaning means 6 for cleaning the toner detection surface of the toner end sensor 5 is attached at a position facing the toner detection surface. The cleaning unit 6 is given a driving force by a motor (not shown), and the rotating shaft of the cleaning unit 6 rotates, so that the scraping portion 6a made of a wire attached to the rotating shaft scrapes off the adhering matter on the toner detection surface. ing.

  FIG. 6 is a flowchart showing the control operation of the cleaning means 6. This flowchart shows an example of the operation when the toner supply device is provided in an image forming apparatus such as a copying machine. In the control operation of the cleaning means 6 in FIG. 6, when the image forming operation (copy) is started, it is confirmed whether or not the uniaxial eccentric screw pump is driven (step S21). If not, the operation of step S21 is performed again. repeat. If it is confirmed that it is driven in step S21, the process proceeds to step S22 and the cleaning means 6 is driven.

  And it progresses to step S23, and the drive confirmation of a uniaxial eccentric screw pump is performed again, and if it is not driving, the confirmation of step S23 will be repeated again, and if it is driving, it will move to step S24. In step S24, if the toner replenishment operation to the sub hopper 1a is stopped, the process returns to step S23. If not stopped, the driving of the cleaning means 6 is stopped in step S25, and the process returns to step S21 again.

  That is, as can be seen from the timing chart of FIG. 7, the cleaning means 6 operates in synchronization with the start of the suction operation of the uniaxial eccentric screw pump (synchronized with (2) ON in the figure), and after the operation, the suction operation and the toner When both operations of the replenishment operation are stopped, they are stopped synchronously (in the figure, both (2) and (4) are synchronized to OFF). The reason why the cleaning means 6 is not stopped only by stopping the suction operation of the single-shaft eccentric screw pump is that the toner supply to the sub hopper 1a may not be finished even after the single-shaft eccentric screw pump stops depending on the balance of the supply amount. is there.

  Therefore, the toner replenishing device according to the third exemplary embodiment includes the cleaning unit 6 for cleaning the toner detection surface of the toner end sensor 5, and the cleaning unit 6 starts the cleaning operation in synchronization with the start of the suction operation of the uniaxial eccentric screw pump. In addition, since both the suction operation and the toner replenishment operation are stopped in synchronization with each other, the detection of the presence / absence of toner in the sub hopper 1a is prevented by removing the toner and foreign matter adhering to the toner detection surface. In addition, the failure rate of the cleaning means 6 and the toner end sensor 5 can be reduced by shortening the driving time by improving the efficiency of the cleaning operation, and the life of the bearings and the like can be improved.

  Next, a toner replenishing device of Example 4 will be described. Note that a description of the same parts as those in the first embodiment will be omitted. FIG. 8 is a cross-sectional view of a main part of the toner supply device of Embodiment 4. In this example, an agitator 7 for stirring is provided as a stirring means at a portion below the sub hopper 1a where toner is deposited. In this example, as in FIG. 5, the toner end sensor 5 and the cleaning means 6 are provided at the same location, but the cleaning means 6 is not shown in FIG.

  As shown in FIG. 8, the stirring agitator 7 is configured by attaching a stirring member 7a formed of a plate material to a rotating shaft and attaching a thin plate member 7b having a hole at the tip of the stirring member 7a. The driving force is given by a motor (not shown), and the stirring member 7a and the thin plate member 7b rotate together with the rotating shaft to stir the toner in the sub hopper 1a.

  FIG. 9 is a flowchart showing the control operation of the stirring agitator 7. This flowchart shows an example of the operation when the toner supply device is provided in an image forming apparatus such as a copying machine. In the control operation of the stirring agitator 7 in FIG. 9, when the image forming operation (copy) is started, it is confirmed whether or not the uniaxial eccentric screw pump is driven (step S31). If not, the operation of step S31 is performed again. repeat. If it is confirmed that it is driven in step S31, the process proceeds to step S32 to drive the stirring agitator 7.

  And it progresses to step S33 and the drive confirmation of a uniaxial eccentric screw pump is performed again, and if it is driving, the confirmation of step S33 will be repeated again, and if it is not driving, it will move to step S34. In step S34, the drive of the stirring agitator 7 is stopped, and the process returns to step S31 again.

  That is, as can be seen from the timing chart of FIG. 7, the stirring agitator 7 operates simultaneously with the start of the suction operation of the uniaxial eccentric screw pump and stops in synchronization with the stop of the uniaxial eccentric screw pump. The stirring agitator 7 improves the replenishability to the single-shaft eccentric screw pump by stirring and fluidizing the toner in the sub hopper 1a. However, if the stirring is excessive, the bulk density of the toner in the sub hopper 1a is reduced. Even if there is no toner, there is a risk of erroneous detection that there is toner. For this reason, unlike the case of the cleaning means 6, it is set as the structure which is not driven more than necessary in synchronization with ON / OFF of the uniaxial eccentric screw pump.

  Therefore, since the toner replenishing device according to the fourth embodiment includes the agitator 7 for agitation that is driven / stopped in synchronization with the suction operation of the uniaxial eccentric screw pump, the toner in the sub hopper 1a is supplied by toner replenishment or suction of the uniaxial eccentric screw pump. In addition to preventing the formation of cavities, the operating time of the stirring agitator 7 is limited to prevent a decrease in the toner bulk density due to excessive stirring, thereby eliminating erroneous detection of the presence or absence of toner, and shortening the drive time by improving the efficiency of the stirring operation Thus, the failure rate of the agitator for stirring 7 can be reduced, and the life of the bearings and the like can be improved.

Next, a toner replenishing device of Embodiment 5 will be described. Since the toner replenishing device used in the fifth embodiment has the same configuration as the toner replenishing device shown in FIG. 8 and only the operation control is different, only the operation will be described with reference to the configuration shown in FIG.
FIG. 11 is a flowchart illustrating the operation of the toner supply device according to the fifth exemplary embodiment. This flowchart shows an example of the operation when the toner supply device is provided in an image forming apparatus such as a copying machine. In this embodiment, when the image forming operation starts, first, information on the toner end sensor in the developing hopper is acquired (step S41), and the presence or absence of toner is confirmed (step S42). If there is toner in step S42, the process returns to step S41, and if there is no toner, the cleaning means 6 and the agitation means 7 are operated (step S43). Then, after operating the cleaning means 6 and the stirring means 7 for a predetermined time (step S44), the uniaxial eccentric screw pump is driven (step S45), and the presence or absence of toner is confirmed again (step S46). If there is no toner in step S46, the process returns to step S45, and if there is toner, the uniaxial eccentric screw pump is stopped (step S47), the cleaning means 6 and the stirring means 7 are stopped (step S48), and the process returns to step S41. During the above-described operation, the sub-hopper 1a also supplies toner from the toner bottle 2 based on information from the toner end sensor 5 as in the second embodiment.

  According to the toner replenishing device shown in the fifth embodiment, the cleaning means 6 and the agitation means 7 are operated prior to driving the uniaxial eccentric screw pump, and the uniaxial eccentric screw pump is driven after a predetermined time to perform cleaning during the operation. Since the operation of the means 6 and the agitation means 7 is continued, the occurrence of air leak (a phenomenon in which an air nest is formed in a tunnel shape) due to insufficient toner agitation in the sub hopper 1a immediately after driving the uniaxial eccentric screw pump is prevented. Thus, good toner conveyance can be performed. Further, by continuing the operation of the agitation means 7 during the operation of the uniaxial eccentric screw pump regardless of the information from the toner end sensor 5, the air leak in the sub hopper 1a during the suction and conveyance of the toner by the uniaxial eccentric screw pump. Can be prevented, and good toner conveyance can be performed.

Next, a toner replenishing device of Example 6 will be described. Since the toner replenishing device used in the sixth embodiment has the same configuration as the toner replenishing device shown in FIG. 8 and only the operation control is different, only the operation will be described with reference to the configuration shown in FIG.
FIG. 12 is a flowchart illustrating the operation of the toner supply device according to the sixth exemplary embodiment. This flowchart shows an example of the operation when the toner supply device is provided in an image forming apparatus such as a copying machine. In this embodiment, when the image forming operation starts, first, information on a timer (not shown) provided in the apparatus is acquired, and it is confirmed whether or not the apparatus has been stopped for a predetermined time (step S51). If the stop time is less than the predetermined value in step S51, the printer waits for no-toner information from the toner end sensor in the developing hopper (step S52). If the stop time is greater than or equal to the predetermined value in step S51, the cleaning means 6 and the stirring means 7 are operated (step S53), and after the cleaning means 6 and the stirring means 7 are operated for a predetermined time (step S54), step S52 is performed. In step (a), waiting for the no-toner information from the toner end sensor in the developing hopper.

  According to the toner replenishing device shown in the sixth embodiment, the cleaning unit 6 and the agitation unit 7 are operated for a predetermined time at the start of operation after the device has been stopped for a predetermined time or longer. Therefore, the toner in the sub hopper 1a left unattended when the device is stopped. Aggregation proceeds and toner suction failure can be prevented from occurring at the start of toner suction and conveyance by the uniaxial eccentric screw pump, and good toner conveyance can be performed even at the start of image formation after leaving the apparatus. Further, since the cleaning unit 6 and the stirring unit 7 are operated only when the apparatus is stopped for a predetermined time or more, it is possible to prevent the toner from being deteriorated by applying stress to the toner by excessive stirring, and further, the cleaning unit 6. And durability of the stirring means 7 grade | etc., Can be improved.

  When the toner supply device is provided in an image forming apparatus such as a copying machine or a printer that forms an image on a transfer material using toner, the above-described effects can be obtained in the image forming apparatus. Further, in the description here, a case where a tube is used as a pipe for toner conveyance is shown. However, other pipes may be used as long as they have a function as a pipe.

  Further, the toner replenishing device shown in each of the above embodiments may be configured to use a polymerized toner that has a constant particle diameter and is easy to perform electrostatic behavior control and contributes to high image quality. Examples of the polymerization toner include P × P (Polyester × Polymerization) toner made of a polyester resin and manufactured by an ester extension polymerization method. This is advantageous for controlling low-temperature fixing, the molecular weight distribution is freely controllable, the particle size distribution is narrow, the charge is almost uniform, the circularity is high, but it is difficult to clean, and it is easy to aggregate due to the environment or leaving Since it has features, a higher effect can be obtained particularly by employing it in the toner replenishing device of the present invention.

  Furthermore, in the present embodiment, an example is shown in which a uniaxial eccentric screw pump is used as the powder pump, which is disposed near the developing hopper 24 and used as a suction pump that sucks toner from the sub hopper 1a to the developing hopper 24. The uniaxial eccentric screw pump may be provided at any position in the middle of the toner conveyance path. When arranged near the sub hopper 1a, the uniaxial eccentric screw pump functions as a discharge pump.

  In the present embodiment, an example in which a uniaxial eccentric screw pump is used as the powder pump has been described. However, the powder pump is not limited to this, and an air pump that sends toner by air pressure, for example, may be used. Even in the configuration using the air pump, the air pump may be arranged at any position on the toner conveyance path, and the air pump functions as a suction pump or a discharge pump according to the arrangement position.

FIG. 3 is a cross-sectional view of a main part of the toner replenishing device used in Example 1 as an embodiment of the present invention. 6 is a flowchart showing a control operation of the toner replenishing device in Example 1 as an embodiment of the present invention. It is principal part sectional drawing of the toner replenishing apparatus used for Example 2 as one Embodiment of this invention. 7 is a flowchart illustrating a control operation of the toner replenishing device according to Example 2 as an embodiment of the present invention. FIG. 6 is a cross-sectional view of a main part of a toner replenishing device used in Example 3 as an embodiment of the present invention. 7 is a flowchart illustrating a control operation of a toner replenishing device according to Example 3 as an embodiment of the present invention. It is a timing chart which shows the operation timing of each operation part in one embodiment of the present invention. FIG. 6 is a cross-sectional view of a main part of a toner replenishing device used in Examples 4 and 5 and 6 as an embodiment of the present invention. 10 is a flowchart illustrating a control operation of a toner replenishing device according to Example 4 as an embodiment of the present invention. FIG. 6 is a cross-sectional view showing a conventional toner replenishing device using a toner cartridge. 10 is a flowchart illustrating a control operation of a toner replenishing device according to Example 5 as an embodiment of the present invention. 10 is a flowchart illustrating a control operation of a toner replenishing device according to Example 6 as an embodiment of the present invention.

Explanation of symbols

1a Reservoir (sub hopper)
2 Toner bottle 3 Driving means 5 Toner end sensor 6 Cleaning means 7 Agitation means 22 Powder pump (uniaxial eccentric screw pump)
33 Piping (Tube)

Claims (8)

A toner replenishing device for supplying toner for forming an image on a transfer material,
A toner bottle having spiral ribs on the inner wall for rotating the toner inside to rotate to the outside;
Drive means for rotating the toner bottle;
A powder pump for conveying the toner discharged from the toner bottle to the developing means side for image formation;
A storage unit that is disposed between the toner bottle and the powder pump and stores toner discharged from the toner bottle;
A toner replenishing device, comprising: a pipe disposed between the powder pump and the storage unit and functioning as a conveyance path for conveying toner to the powder pump. The toner replenishing device according to claim 1.
Control for controlling toner supply to the storage unit based on the presence or absence of toner detected by the toner end sensor, including a toner end sensor for detecting the toner amount in order to keep the toner amount in the storage unit constant And a toner replenishing device. The toner replenishing device according to claim 2.
Cleaning means for cleaning the detection surface of the toner end sensor is provided, and the control unit drives the cleaning means in synchronization with the start of operation of the powder pump, and operation of the powder pump and toner supply operation to the storage unit A toner replenishing device that stops the cleaning means synchronously when both of them stop. The toner replenishing device according to claim 2 or 3,
An agitation unit for agitating the toner is provided in the storage unit, and the control unit drives the agitation unit in synchronization with the operation start of the powder pump, and the agitation unit in synchronization with the operation stop of the powder pump. And a toner replenishing device. The toner replenishing device according to claim 2.
A cleaning means for cleaning the detection surface of the toner end sensor; and a stirring means for stirring the toner in the storage section. The control section prior to the operation of the powder pump, the cleaning means and the stirring means. The toner replenishing device is characterized in that the powder pump is operated after a predetermined time after the operation, and the operation of the cleaning means and the stirring means is continued during the operation of the powder pump. The toner replenishing device according to claim 2.
A cleaning unit for cleaning a detection surface of the toner end sensor; and an agitation unit for agitating the toner in the storage unit. The control unit is configured to start the operation after the apparatus has been stopped for a predetermined time or more. And a toner replenishing device which operates the stirring means for a predetermined time. The toner replenishing device according to any one of claims 1 to 6,
A toner replenishing device using polymerized toner. An image forming apparatus comprising the toner supply device according to claim 1.

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