JP2017134155A - Toner supply device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner supply device that prevents, by a simple configuration, toner leakage during its detachment and to provide an image forming apparatus in which the toner supply device is mounted.SOLUTION: A toner supply device comprises: a toner storage container that is detachable; and a toner storage part located downstream of it and upstream of a development processing part, and having a toner storage part smaller in toner capacity than the toner storage container. Additionally, the toner storage part has: a toner receiving port that receives supply of toner from the toner storage container; a stirring member that rotates around a rotation shaft laterally disposed below the toner receiving port and agitates toner by a rotating operation; and a toner feed port disposed below the rotation shaft of the stirring member and in a place where toner flows in by a rotating operation of the stirring member and configured to feed toner to the development processing part. Here, a control part is provided, which performs a rotating operation of the stirring member by a predetermined amount of rotation after the time (T) of an operation of supplying toner from the toner storage container to the toner storage part.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a toner replenishing device that replenishes toner to a development process unit in an image forming apparatus. More specifically, the present invention relates to a toner replenishing device in which a toner container is detachable and prevents toner leakage at the time of detachment. An image forming apparatus equipped with the toner replenishing device is also an object of the present invention.

  2. Description of the Related Art Conventionally, in an image forming apparatus, as described in Patent Document 1, for example, a removable toner container is provided. The toner container stores toner to be replenished to the development process section. When the toner in the toner container is exhausted, the toner container is replaced with a new one in order to continue image formation. In the device described in Patent Document 1, “34” in FIG. 1 (“cartridge 34” in [0016] in the text) corresponds to this toner container.

JP-A-5-323785

  However, the conventional technique described above has the following problems. That is, the toner container is detachable, but the toner may leak during the detachment. In particular, toner leakage tends to occur when the empty toner container is removed. This is because there is a possibility that the toner remains in the connection portion between the toner container and the image forming apparatus main body side even though the toner container is empty. Further, unlike the toner leakage at the time of attachment, the residual toner leakage at the time of removal is not easily prevented by the structure of the toner container. In order to prevent toner leakage at the time of removal by the structure of the connecting portion on the toner container or the image forming apparatus main body side, it is necessary to have a complicated structure such as a double shutter and a large capacity of the toner storage part. This necessitated an increase in the size of the device.

  The present invention has been made to solve the above-described problems of the prior art. That is, an object of the present invention is to provide a toner replenishing device that prevents toner leakage during removal with a simple configuration. The present invention also provides an image forming apparatus equipped with the toner replenishing device.

  A toner replenishing device according to an aspect of the present invention is a device that replenishes toner to a development process section of an image forming apparatus that forms an image with toner, and includes a removable toner storage container and a toner storage container to the development process section. A toner reservoir having a toner capacity smaller than that of the toner container, the toner reservoir having a toner receiving port formed at an upper portion for receiving toner from the toner container; A stirring member that rotates about a rotating shaft that is disposed laterally below the toner receiving port and that stirs the stored toner by a rotating operation, and a rotating member that is below the rotating shaft of the stirring member and rotates. It is arranged at a position where toner flows in by operation, and is provided with a toner feed port for feeding toner to the development process section. And a control unit for causing rotation of a predetermined rotation of the agitating member after the end of the toner supply operation to the reservoir.

  In this toner replenishing device, the toner reservoir has the following two basic functions. That is, the function of supplying the toner to the developing process section of the image forming apparatus, and for that purpose, the toner is supplied from the toner container and stored. Then, after the toner is supplied from the toner container, the rotation operation of the stirring member is performed over a predetermined rotation amount under the control of the control unit. This prevents toner from remaining in the vicinity of the toner receiving port, and prevents toner leakage when the toner container is removed.

  In the toner replenishing device according to this aspect, it is preferable that the control unit causes the stirring member to rotate during and after the toner supply operation from the toner container to the toner storage unit. As a result, the upper surface of the toner in the toner reservoir can be more reliably flattened, and as much toner as possible can be accommodated in the toner reservoir while preventing toner from remaining near the toner receiving port.

  In the toner replenishing device according to this aspect, the stirring member is composed of a first flexible member and a second flexible member provided on opposite sides of the rotation shaft, and the first flexible member and the first flexible member. 2 The length from the rotating shaft is different from that of the flexible member, and the control unit performs the rotating operation of the stirring member by selecting the longer one of the first flexible member and the second flexible member from the rotating shaft. It is desirable to stop in a state where it is directed downward than the shorter one. As a result, the stirring operation is stopped when the toner in the toner storage portion is poured into the toner feed port as much as possible, so that more toner can be received from the toner storage container in the toner storage portion thereafter.

  The toner replenishing device according to this aspect is further provided with a toner detection member that is in contact with the toner in the toner reservoir from above and a position that is eccentric with respect to the rotation shaft of the stirring member, and the toner detection member is intermittently moved when the stirring member rotates. Forcibly ascending the cam member, and the control unit is configured to supply toner from the toner container to the toner storage unit when the stop position of the toner detection member is equal to or lower than a predetermined first height. And the toner supply operation from the toner container to the toner reservoir is terminated when the stop position of the toner detection member is higher than the first height and higher than a predetermined second height. The second height is preferably higher than the height corresponding to half of the maximum depth at which the toner can be stored in the toner storage portion. Thus, toner supply from the toner storage container to the toner storage unit can be started when the toner in the toner storage unit decreases, and supply can be stopped when the amount of toner in the toner storage unit is almost full.

  The toner replenishing device according to this aspect further includes a toner conveying member that sends the toner that has entered the toner feeding port to the developing process unit, and a drive transmission system that transmits a driving force from a common driving source to the stirring member and the toner conveying member. The drive transmission system includes a transmission gear, an agitation gear connected to the agitation member, a conveyance gear connected to the toner conveyance member, a reverse gear meshing with the agitation gear, and swinging with respect to the transmission gear while meshing with the transmission gear. Thus, the transmission gear has a first position that meshes with the conveyance gear when the transmission gear rotates in the forward direction, and a second position that does not mesh with the conveyance gear when the transmission gear rotates in the reverse direction. On the other hand, at one of the first position and the second position, the drive is transmitted without passing through the reverse gear, and at the other of the first position and the second position, the drive is transmitted through the reverse gear. Transmission It is desirable that shall.

  By having such a drive transmission system, the state in which both the agitating member and the toner conveying member are driven and the state in which only the agitating member is driven without the need to provide separate driving sources can be obtained. It can be switched according to the direction of rotation. In any case, the rotation direction of the stirring member is the same. Thereby, the number of drive sources can be reduced.

  In the toner replenishing device according to this aspect, the control unit further determines the duration of the rotation of the agitating member after the toner supply operation from the toner storage container to the toner storage unit is completed after the toner storage container is replaced. It is desirable to make it longer than otherwise. This is because the amount of toner supplied from the toner container to the toner reservoir after the toner container has been replaced tends to be larger than in a normal case, so it is desirable to level the upper surface of the toner more reliably. Alternatively, when the toner supply operation from the toner container to the toner storage unit is started from the situation where the stop position of the toner detection member is lower than the first height and lower than the predetermined third height. , The duration of the subsequent rotation of the stirring member may be made longer than usual.

  In the toner replenishing device according to this aspect, the control unit determines in advance the duration of the rotation of the stirring member after the toner supply operation from the toner container to the toner storage unit is completed, and the toner supply frequency to the development process unit is determined in advance. If it is higher than the standard, it is better to make it longer than otherwise. This is because the amount of toner supplied from the toner container to the toner reservoir tends to increase in such a case.

  Another aspect of the present invention is an image forming apparatus that includes any of the toner replenishing devices described above, and that forms an image on a medium using toner replenished from the toner replenishing device.

  According to this configuration, there is provided a toner replenishing device that prevents toner leakage during removal with a simple configuration. An image forming apparatus equipped with the toner replenishing device is also provided.

1 is a schematic configuration diagram of an image forming apparatus according to the present embodiment. FIG. 6 is a perspective view of a toner supply unit. FIG. 3 is a front sectional view (part 1) of a sub hopper and a toner bottle. It is a perspective view which shows a sub hopper in a partial incision state. It is a perspective view which shows the external appearance of a sub hopper and its periphery. It is a rear view which shows the drive mechanism of a stirring member and a conveyance screw. FIG. 6 is a front sectional view (No. 2) of a sub hopper and a toner bottle. 6 is a timing chart illustrating an example of a relationship between rotation of a stirring member and toner supply from a toner bottle. FIG. 4 is a front cross-sectional view illustrating a state where toner is excessively supplied from a toner bottle. It is a front sectional view showing a state where toner is fully supplied to the sub hopper. It is a front sectional view showing a state where toner is not fully supplied to the sub hopper.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows a schematic configuration of an image forming apparatus 1 of the present embodiment. The image forming apparatus 1 in FIG. 1 is a so-called tandem type color printer having an intermediate transfer belt 20.

  The image forming apparatus 1 includes four color image forming units 10Y, 10M, 10C, and 10K arranged along the lower side of the intermediate transfer belt 20. Each of the image forming units 10Y to 10K includes a photoconductor 11, a charging device 12, an exposure device 13, a developing device 14, and a primary transfer roller 15. A secondary transfer roller 23 is provided at the right end of the intermediate transfer belt 20 in FIG. A fixing device 40 is provided above the secondary transfer roller 23. In addition, a paper feed cassette 31 is disposed in the lower part of the image forming apparatus 1. As a result, toner images are formed by the image forming units 10Y to 10K, the toner images are transferred onto the paper P supplied from the paper feed cassette 31, and the paper is fixed by the fixing device 40. Image formation is performed. The image forming apparatus 1 is also provided with a control unit 16 that controls various operations.

  Toner replenishing portions 50Y, 50M, 50C, and 50K are disposed above the intermediate transfer belt 20 in the image forming apparatus 1. The toner replenishing units 50Y to 50K replenish toner to the developing devices 14 of the corresponding color image forming units 10Y to 10K. The toner replenishing units 50Y to 50K are configured as shown in FIG. 2 is a perspective view of the toner replenishing units 50Y to 50K as viewed obliquely from above, and the upper part in FIG. 2 corresponds to the back side in the depth direction of the image forming apparatus 1 in FIG. A cylindrical toner bottle 60 is attached to each of the toner supply units 50Y to 50K. The toner bottle 60 is a toner container, and contains toner of a corresponding color for replenishment. Each toner bottle 60 can be individually attached and detached toward the lower side in FIG. 2, that is, toward the front side in the depth direction in the image forming apparatus 1 of FIG.

  Each of the toner replenishing units 50Y to 50K is provided with a bottle mounting unit 71 on which the toner bottle 60 is mounted. The bottle mounting portion 71 is a component on the main body side of the image forming apparatus 1, and is located on the back side of the intermediate transfer belt 20 in the depth direction of the image forming apparatus 1. A sub hopper 70 is attached to the lower part of each bottle mounting portion 71.

  FIG. 3 shows a cross-sectional view of the sub hopper 70 as viewed from the front side. In FIG. 3, in addition to the sub hopper 70, a cross section of the toner bottle 60 also appears. 4 is a perspective view of the sub hopper 70 in a partially cut state. A hollow toner reservoir 72 is formed inside the sub hopper 70. The toner storage unit 72 can store toner to some extent. However, FIGS. 3 and 4 depict an empty state where there is no toner in the toner reservoir 72. The sub hopper 70 is located in the middle of the toner supply path from the toner bottle 60 to the developing device 14, and the toner capacity thereof is smaller than the toner capacity of the toner bottle 60. The sub hopper 70 receives supply of toner from the toner bottle 60 and stores the toner in the toner storage unit 72, and sends the toner stored in the toner storage unit 72 toward the developing device 14. is there.

  The sub hopper 70 is formed with a toner receiving port 73 for receiving toner from the toner bottle 60. The toner receiving port 73 is located above the toner storage unit 72. The sub hopper 70 is further provided with a toner delivery unit 74. The toner delivery unit 74 is a part that sends the toner stored in the toner storage unit 72 to the developing device 14. Although not shown, the toner delivery unit 74 and the developing device 14 are connected via a position on the back side of the intermediate transfer belt 20. The toner delivery unit 74 is provided with a conveying screw 75.

  In the sub hopper 70, a partition wall 76 is provided between the toner storage part 72 and the toner delivery part 74. However, as shown in FIG. 4, an opening-shaped toner feed port 77 is formed in the partition wall 76. The toner can flow from the toner storage part 72 to the toner delivery part 74 through the toner delivery port 77.

  A stirring member 78 is provided inside the toner storage unit 72. The stirring member 78 is a flexible film member attached to the rotating shaft 79. The rotation shaft 79 is provided at a substantially middle height position with respect to the depth direction of the toner storage portion 72. The stirring member 78 rotates with the rotating shaft 79. The agitating member 78 is asymmetrically attached to the rotating shaft 79 and has a major axis portion 80 having a major axis and a minor axis unit 81 having a minor axis. The long diameter portion 80 and the short diameter portion 81 are located on the opposite side with respect to the rotation shaft 79. The long diameter portion 80 contacts the bottom surface of the toner storage portion 72 when positioned below the rotation shaft 79, but the short diameter portion 81 does not contact the bottom surface of the toner storage portion 72 even when positioned below the rotation shaft 79.

  Further, an eccentric cam 82 is attached to the rotating shaft 79 of the stirring member 78. When the rotary shaft 79 rotates, the position of the eccentric cam 82, particularly the height, repeatedly fluctuates with the rotation. The eccentric cam 82 is shifted from the rotation shaft 79 on the same side as the long diameter portion 80. For this reason, when the long diameter portion 80 is positioned below the rotation shaft 79, the eccentric cam 82 is also at a low position, and when the long diameter portion 80 is positioned above the rotation shaft 79, the eccentric cam 82 is also at a high position. Further, the eccentric cam 82 is positioned toward the end with respect to the axial direction of the rotating shaft 79, avoiding the stirring member 78.

  A detection member 83 is also provided inside the toner reservoir 72. The detection member 83 swings about the swing shaft 84, and moves up and down to some extent in a substantially horizontal state with respect to the swing shaft 84. The swing shaft 84 is parallel to the rotation shaft 79 and is disposed at a position higher than the rotation shaft 79. That is, the swing shaft 84 is provided at a position higher than the center of the toner storage portion 72 in the depth direction. As shown in FIG. 4, the detection member 83 has a flat plate-shaped restricting portion 85. The restricting portion 85 is located some distance away from the swing shaft 84 and is connected to the swing shaft 84 by an arm portion 86. The arm portion 86 is positioned toward the end with respect to the axial direction of the rotating shaft 79 while avoiding the stirring member 78. Thereby, even if the stirring member 78 rotates, it does not contact the detection member 83 so much.

  On the other hand, when the eccentric cam 82 is raised by the rotation of the stirring member 78, the arm portion 86 is lifted by the eccentric cam 82. FIG. 4 shows a state where the detection member 83 is lifted through the arm portion 86 as described above. In this state, even if toner is stored in the toner storage unit 72, the regulation unit 85 escapes from the stored toner.

  When the stirring member 78 is further rotated from this state, the eccentric cam 82 is lowered, but the detection member 83 is not lowered so much depending on the amount of toner stored in the toner reservoir 72. This is because when the restricting portion 85 lands on the surface of the stored toner, further lowering of the detection member 83 is prevented by the stored toner. That is, the position of the detection member 83 is the higher of the position where the restricting portion 85 is restricted by the stored toner and the position where the arm portion 86 is restricted by the eccentric cam 82.

  When toner is supplied from the toner bottle 60 to the toner storage part 72, the regulation part 85 may be buried in the stored toner. However, after that, when the stirring member 78 is rotated to some extent and the stirring member 78 is stopped in a state where the eccentric cam 82 is lowered, as described above, the detection member 83 is kept in a state where the lowering is restricted by the stored toner. Will stop. The stop position of the detection member 83 in this state is a position that reflects the amount of toner stored in the toner storage unit 72.

  Thus, the amount of stored toner in the toner storage unit 72 can be known by detecting the position of the detection member 83. Therefore, in the image forming apparatus 1 of this embodiment, the sub hopper 70 is provided with a mechanism for detecting the position of the detection member 83. That is, as shown in the external perspective view of FIG. 5, a detection plate 87 and a sensor 88 are provided outside the sub hopper 70. 4 and 5, the angle at which the sub-hopper 70 is viewed is almost the same, although there is a difference between the incision state and the appearance.

  The end of the swing shaft 84 protrudes to the outside of the sub hopper 70, and the detection plate 87 is attached thereto. As a result, the detection plate 87 moves integrally with the movement of the detection member 83 in the toner reservoir 72. The positional relationship between the detection plate 87 and the sensor 88 changes depending on the position of the detection plate 87. Thereby, the sensor 88 can detect the position of the detection plate 87, that is, the position of the detection member 83 in the toner storage portion 72. Therefore, the amount of toner stored in the toner storage unit 72 can be known by the sensor 88. The detection signal of the sensor 88 is notified to the control unit 16. The sensor 88 may be of any type as long as it can detect the position of the detection plate 87, such as an optical type or a magnetic type. Although the stored toner itself is not shown in FIG. 3, the position of the detection member 83 in FIG. 3 is a position when the toner storage portion 72 is almost filled with the stored toner.

  Next, the drive mechanism for the stirring member 78 and the conveying screw 75 will be described. Therefore, FIG. 6 shows the configuration of this drive system. FIG. 6 corresponds to a rear view of the sub hopper 70 portion. As shown in FIG. 6, on the back side of each sub hopper 70, a motor 89 that is a drive source for the stirring member 78 and the conveying screw 75 is provided. Further, a stirring gear 90 connected to the rotation shaft 79 and a transport gear 91 connected to the transport screw 75 are provided. Further, a first transmission gear 92, a second transmission gear 93, a swing gear 94, and a reverse gear 95 are provided. Among these, the first transmission gear 92, the second transmission gear 93, and the reverse gear 95 have fixed shaft positions. Further, rotation of the first transmission gear 92 and the second transmission gear 93 is always transmitted from the motor 89. The reverse gear 95 is always meshed with the stirring gear 90.

  The swing gear 94 has a shaft position that is movable on a circumference around the shaft position of the second transmission gear 93. When the second transmission gear 93 is rotated clockwise as in “forward rotation” on the right side of FIG. 6, the shaft position of the swinging gear 94 is also dragged by the rotation and moves downward in FIG. 6. When the swing gear 94 meshes with both the stirring gear 90 and the transport gear 91, the axial position of the swing gear 94 is determined. By rotating the second transmission gear 93 further clockwise in this state, the rotation is transmitted to both the stirring gear 90 and the transport gear 91. In this state, the oscillating gear 94 and the reverse gear 95 are not engaged with each other. Note that the second transmission gear 93 and the conveyance gear 91 appear to be close to each other in FIG. 6, but are not directly meshed with each other.

  On the other hand, when the second transmission gear 93 is rotated counterclockwise as in the case of “reverse rotation” on the left side of FIG. 6, the shaft position of the swinging gear 94 is also dragged by the rotation and slightly upwards to the left in FIG. 6. Moving. When the swinging gear 94 meshes with the reverse rotation gear 95, the axial position of the swinging gear 94 is determined. In this state, the oscillating gear 94 is not engaged with the transport gear 91. Further, it does not mesh directly with the stirring gear 90. By rotating the second transmission gear 93 further counterclockwise in this state, the rotation is transmitted only to the stirring gear 90 without transmitting the rotation to the transport gear 91.

  Note that the rotating direction of the stirring gear 90 is the same in both cases of normal rotation and reverse rotation. The direction of rotation is clockwise in FIG. 6, which corresponds to counterclockwise in FIG. Therefore, by rotating the second transmission gear 93 as described above, the stirring member 78 in FIG. 3 rotates counterclockwise. As is apparent from FIGS. 3 and 4, this rotation direction of the stirring member 78 is a rotation direction in which the toner stored in the toner storage unit 72 flows into the toner delivery unit 74 from the toner feed port 77.

  From the above, in the drive system of FIG. 6, a state in which both the stirring member 78 and the conveying screw 75 are driven (forward rotation) and a state in which only the stirring member 78 is driven (reverse rotation) are selected according to the rotation direction of the motor 89. it can. In either case, the rotation direction of the stirring member 78 is the same. For this reason, it is possible to rotate only the stirring member 78 while the conveying screw 75 is stopped. On the other hand, when the conveying screw 75 is rotated, the stirring member 78 is also necessarily rotated.

  Further, in FIG. 6, in the two adjacent sub hoppers 70, the rotation direction of the motor 89 is depicted to be opposite, but this is not essential. The rotation state of the motor 89 in each color is controlled independently according to the consumption state of the toner of each color. Of course, the control is performed by the control unit 16.

  Subsequently, the operation of the image forming apparatus 1 of the present embodiment will be described. The characteristic operation of the image forming apparatus 1 as the present invention is the stirring operation of the stirring member 78 in the sub hopper 70. Therefore, an emphasis is placed on this stirring operation, and a description of a general image forming operation is omitted.

  As described above, the basic role of the sub hopper 70 in the image forming apparatus 1 is to supply the toner to the developing device 14 and to store the toner supplied from the toner bottle 60 for that purpose. Toner is supplied from the sub hopper 70 to the developing device 14 by rotating the motor 89 forward as shown on the right side of FIG. As a result, the conveying screw 75 rotates, and the toner is sent from the toner sending portion 74 of the sub hopper 70 to the developing device 14. At the same time, the agitating member 78 rotates counterclockwise in FIG. 3 and causes the toner to flow from the toner storage portion 72 to the toner delivery portion 74. In addition, the toner is supplied from the toner bottle 60 to the sub hopper 70 by rotating the cylindrical toner bottle 60 around the axis (refer to Japanese Patent Laid-Open No. 2006-4257 [0041] for details). ).

  Specifically, the supply of toner from the toner bottle 60 to the sub hopper 70 may be started when the position where the detection member 83 stops by the toner becomes a position equal to or lower than a predetermined first height. . Further, the supply of toner from the toner bottle 60 may be stopped when the stop position becomes a position equal to or lower than a predetermined second height. Of course, the second height is higher than the first height. The second height is preferably higher than at least the height corresponding to half of the maximum depth of the toner reservoir 72.

  In the image forming apparatus 1, whenever the stirring member 78 is stopped, the stirring is performed in a state where the long diameter portion 80 is positioned on the lower side and the short diameter portion 81 is positioned on the upper side with respect to the rotation shaft 79. The stirring member 78 in FIG. 3 is in such a state. As a result, the agitation is finished in a state where the toner is poured from the toner storage unit 72 to the toner delivery unit 74. By doing so, the upper surface of the toner in the toner storage portion 72 can be lowered as much as possible with respect to the total amount of toner in the sub hopper 70, and the detection of the toner amount reduction by the detection member 83 can be reliably performed. It is. In this state, the eccentric cam 82 is also lowered, and the detection of the toner amount by the detection member 83 is not hindered by the eccentric cam 82.

  If the agitating member 78 is stopped with the long diameter portion 80 facing upward (see FIG. 7), the upper surface of the toner in the toner storage portion 72 is lowered with respect to the total amount of toner in the sub hopper 70. It can be a state that is not. In this case, even if the total amount of toner in the sub hopper 70 is reduced, this may not be detected by the detection member 83. As a result, the toner supply command to the toner bottle 60 may be delayed. Further, since the eccentric cam 82 is raised, the detection member 83 remains lifted by the eccentric cam 82, which may cause an obstacle to toner amount detection. In this embodiment, such a situation is prevented by stopping the stirring member 78 with the long diameter portion 80 facing downward.

  When the upper surface of the toner in the toner reservoir 72 is lowered by supplying the toner to the developing device 14, this is detected by the detection member 83. Then, toner is supplied from the toner bottle 60 to the sub hopper 70 in accordance with a command from the control unit 16. The toner supplied from the toner bottle 60 flows into the toner reservoir 72 through the toner receiving port 73 shown in FIG.

  In this embodiment, the stirring member 78 is always rotated after the toner supply from the toner bottle 60 to the sub hopper 70 is performed. The reason is to prevent a part of the toner supplied from the toner bottle 60 from remaining in the vicinity of the toner receiving port 73. When the agitating member 78 is rotated after the toner supply from the toner bottle 60 is received, the toner near the toner receiving port 73 flows into the toner storage portion 72 due to vibration accompanying the rotation. For this reason, even if the toner bottle 60 is subsequently removed, the toner does not remain in the vicinity of the toner receiving port 73 and the toner does not leak.

  The rotation of the stirring member 78 after the toner supply from the toner bottle 60 may be performed by the reverse rotation of the motor 89 as shown on the left side of FIG. This is because only the stirring member 78 can be rotated without wastefully rotating the conveying screw 75. Of course, when there is a print job at that timing and toner supply to the developing device 14 is necessary, the rotation may be performed by the motor 89 shown on the right side of FIG.

  Further, the rotation of the agitating member 78 may be started after the toner supply from the toner bottle 60 is completed, or the agitating member 78 is also rotated during the toner supply from the toner bottle 60, and the agitation is also performed after the supply is completed. The rotation of the member 78 may be continued. In any case, the necessary amount of rotation of the stirring member 78 after completion of the toner supply is determined in advance and rotated so that the amount of rotation is achieved. The necessary amount of rotation may be determined so that the number of rotations around the rotation shaft 79 of the stirring member 78 becomes a predetermined number of rotations, for example, depending on the rotation time. For the predetermined number of laps, several laps are sufficient, and even one lap may be sufficient.

  Further, the necessary rotation amount is not necessarily uniform, and may vary depending on the case. For example, when the toner supply from the toner bottle 60 is performed in a situation where the amount of toner stored in the sub hopper 70 decreases as it is nearly empty, the necessary amount of rotation is increased as compared with a normal case where the toner is not supplied. It is possible. In such a case, since the amount of toner supplied from the toner bottle 60 is large, the undulation of the upper surface of the toner tends to be large. For this reason, in order to make the upper surface of the toner more uniform, it is necessary to perform more stirring of the toner by the stirring member 78. For example, this is the case when toner is supplied from the toner bottle 60 after the toner bottle 60 itself becomes toner empty and waits for its replacement.

  Specifically, for example, when the amount of stored toner immediately before the toner supply from the toner bottle 60 is lower than the first height and equal to or smaller than a predetermined third height, the stirring member 78 It is possible to increase the amount of rotation. Alternatively, it is conceivable to increase the amount of rotation of the agitating member 78 in the case of supplying toner from the first toner bottle 60 after the toner bottle 60 is detached.

  Similarly, when toner is supplied from the toner bottle 60 in a situation where the frequency of toner supply from the sub hopper 70 to the developing device 14 is high, a larger amount of rotation is required than in a normal case where the toner is not supplied. It is possible to do. This is because the amount of toner supplied from the toner bottle 60 is large even in such a case. Such a case occurs when a large number of images including a solid figure of a large area are continuously printed. A reference value may be set in advance for the frequency of toner supply from the sub hopper 70 to the developing device 14, and the amount of rotation may be increased when the situation exceeds the reference value. In any of the above cases, in practice, the number of revolutions of the agitating member 78 after completion of the toner supply from the toner bottle 60 may be increased by one or two rounds compared to the normal case.

  FIG. 8 shows a timing chart of an example of a timing relationship between the rotation of the stirring member 78 and the toner supply from the toner bottle 60. FIG. 8 shows an example in which the stirring member 78 is continuously rotated from the supply of toner from the toner bottle 60 to the end of supply. “TB drive” in FIG. 8A indicates ON / OFF of toner supply from the toner bottle 60. The “stirring drive” in (B) indicates turning on / off of the stirring member 78. In FIG. 8, a “detection sensor” (C) is further provided, which indicates the detection of the amount of stored toner by the detection member 83.

  It is assumed that toner supply from the sub hopper 70 to the developing device 14 is started at time t0. Since this is performed by forward rotation of the motor 89 as shown in FIG. 6, the rotation (B) of the stirring member 78 is necessarily started at time t0. It is assumed that toner supply (A) from the toner bottle 60 to the sub hopper 70 is started at time t1 thereafter. Furthermore, it is assumed that the supply of toner from the sub hopper 70 to the developing device 14 is completed at time t2. Then, as described in FIG. 6, the rotation direction of the motor 89 is switched from normal rotation (right side) to reverse rotation (left side). Thus, the rotation of only the stirring member 78 is continued while the rotation of the conveying screw 75 is stopped (B). At this time, while the position of the rocking gear 94 in FIG. 6 is changed, the rotation of the conveying screw 75 is temporarily reduced, but the time required is actually very small.

  Further, at time t3 thereafter, it is assumed that the sub hopper 70 is full and the supply of toner from the toner bottle 60 is stopped (A). However, at this time, the stirring member 78 is not stopped immediately, but the stirring member 78 is stopped at a time t4 after a predetermined time has elapsed (B). The time lag T from time t3 (stop of the toner bottle 60) to time t4 (stop of the stirring member 78) is a characteristic point of the image forming apparatus 1 of the present embodiment.

  Note that the detection D of the stored toner amount can be appropriately performed by the detection member 83 during the period from time t0 to time t3 (C). Further, the stored toner amount detection E can be performed during the period from time t3 to time t4. By performing the detection E of the stored toner amount after time t3, there are the following advantages. That is, the toner supply from the toner bottle 60 can be stopped before the toner 96 remaining in the vicinity of the toner receiving port 73 is in a state (FIG. 9) where it cannot be accommodated in the toner reservoir 72.

  In the image forming apparatus 1 of the present embodiment, it is desirable that supply of toner from the toner bottle 60 is stopped in a state where as much toner 96 as possible is contained in the sub hopper 70 (FIG. 10). This is to increase the number of sheets that can be printed between the time when the toner bottle 60 shows toner empty and the time when the toner bottle 60 is replaced. If the toner supply from the toner bottle 60 is stopped in a situation where there is room for the toner capacity in the sub hopper 70 as shown in FIG. 11, the number of printable sheets in the above situation will be small. Because. On the other hand, the situation shown in FIG. 9 should not be allowed. Therefore, it is necessary to detect the amount of stored toner with high accuracy, particularly near the upper limit of the toner capacity in the sub hopper 70.

  In this embodiment, this point is dealt with by arranging the swing shaft 84 of the detection member 83 at a high position in the toner reservoir 72. In other words, if the position of the swing shaft 84 is low, the arm portion 86 of the detection member 83 moves relative to the swing shaft 84 when detecting the upper surface of the stored toner 96 at a position near the upper limit in the toner storage section 72. It will be in a state of leaning upward. In this case, the angle variation of the detection member 83 is too large with respect to the slight height variation of the upper surface of the stored toner 96, and the reliability of measurement cannot be ensured. In this embodiment, the swing shaft 84 is disposed at a high position in the toner storage portion 72, so that the arm portion 86 remains substantially horizontal even when the toner storage portion 72 is almost full, and the upper surface of the stored toner 96 is covered. It can be detected. Thereby, the detection accuracy of the stored toner amount in the vicinity of the upper limit of the toner capacity in the sub hopper 70 is increased.

  As described above in detail, according to the present embodiment, the toner supply system for supplying the toner to the developing device 14 in the image forming apparatus 1 is the removable toner bottle 60 and the toner positioned downstream from the toner bottle 60. A sub hopper 70 having a smaller capacity than the bottle 60 is provided. A stirring member 78 is provided in the toner storage portion 72 of the sub hopper 70, and stirring is performed for a predetermined time after the toner is supplied from the toner bottle 60 to the sub hopper 70. This prevents toner from remaining in the toner receiving port 73 and prevents toner leakage when the toner bottle 60 is removed. Further, the detection accuracy of the toner amount in the toner storage unit 72 is increased. Thus, a toner replenishing device that prevents leakage of toner at the time of removal with a simple configuration is realized. In addition, the replenishment operation is stopped in a state where as much toner as possible from the sub-hopper 70 is replenished from the toner bottle, thereby securing the number of printed sheets after emptying. Further, an image forming apparatus 1 equipped with the toner replenishing device is also realized.

  Note that this embodiment is merely an example, and does not limit the present invention. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof.

  For example, the form of the toner bottle 60 is not limited to the so-called blow bottle type shown in FIG. Further, in the drive mechanism shown in FIG. 6, drive transmission from the swing gear 94 to the stirring gear 90 is performed without going through the reverse gear 95 during forward rotation, and via the reverse gear 95 during reverse rotation. This may be reversed. Alternatively, the reverse gears may be two sets of odd-numbered (including one) and even-numbered gears, and drive transmission may be transmitted to the stirring gear 90 via one of them depending on the rotation direction of the motor 89. Good. Alternatively, the oscillating gear 94 may be eliminated by separately providing a motor for driving the stirring member 78 and a motor for driving the conveying screw 75. Further, the type of the image forming apparatus 1 is not limited to a color type but may be a monochrome type, and is not limited to a printer but may be a copier. It may have a function of exchanging print jobs through a public line.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 10Y-10K Image forming part 14 Developing apparatus 16 Control part 50Y-50K Toner replenishment part 60 Toner bottle 70 Subhopper 72 Toner storage part 73 Toner receiving port 74 Toner sending part 75 Conveying screw 77 Toner sending port 78 Stirring member 79 Rotating shaft 80 Long diameter portion 81 Short diameter portion 82 Eccentric cam 83 Detection member 84 Oscillating shaft 85 Restricting portion 86 Arm portion 88 Sensor 89 Motor 90 Stirring gear 91 Conveying gear 92 First transmission gear 93 Second transmission gear 94 Oscillating gear 95 Reverse gear 96 Retained toner

Claims (8)

A toner replenishing device for replenishing toner to a development process section of an image forming apparatus that forms an image with toner,
A removable toner container,
A toner storage part located in the middle of a toner supply path from the toner container to the development process part, and having a toner capacity smaller than that of the toner container;
In the toner reservoir,
A toner receiving port formed on the top and receiving toner from the toner container;
A stirring member that rotates about a rotating shaft that is disposed laterally below the toner receiving port and that stirs the stored toner by a rotating operation;
A toner feeding port that is disposed below the rotation axis of the stirring member and into which toner flows in by the rotation of the stirring member, and that feeds toner to the development process unit;
A toner replenishing device comprising: a control unit configured to perform a predetermined amount of rotation of the stirring member after completion of toner supply operation from the toner container to the toner storage unit. The toner replenishing device according to claim 1, wherein the control unit includes:
A toner replenishing device, wherein the rotating operation of the agitating member is performed during and after the toner supply operation from the toner container to the toner reservoir. The toner replenishing device according to claim 1 or 2,
The stirring member is composed of a first flexible member and a second flexible member provided on opposite sides of the rotating shaft,
The first flexible member and the second flexible member have different lengths from the rotating shaft,
The control unit stops the rotating operation of the stirring member in a state where the longer one of the first flexible member and the second flexible member from the rotating shaft is directed downward than the shorter one. A toner replenishing device characterized by that. A toner replenishing device according to any one of claims 1 to 3,
A toner detection member in contact with the toner in the toner reservoir from above;
A cam member provided at a position eccentric with respect to the rotation shaft of the stirring member, and forcibly forcibly raising the toner detection member when the stirring member rotates,
The controller is
A toner supply operation from the toner container to the toner storage unit is started when the stop position of the toner detection member is a position equal to or lower than a predetermined first height;
When the stop position of the toner detection member is higher than the first height and is equal to or higher than a predetermined second height, the toner supply operation from the toner container to the toner storage unit is terminated. ,
The toner replenishing device, wherein the second height is higher than a height corresponding to half of a maximum depth in which toner can be stored in the toner storage portion. A toner replenishing device according to any one of claims 1 to 4,
A toner conveying member that feeds the toner that has entered the toner feeding port to the developing process unit;
A drive transmission system for transmitting a driving force from a common drive source to the stirring member and the toner conveying member;
The drive transmission system includes
A transmission gear,
A stirring gear connected to the stirring member;
A transport gear connected to the toner transport member;
A reverse gear meshing with the stirring gear;
By swinging with respect to the transmission gear while meshing with the transmission gear, the first position is meshed with the transport gear when the transmission gear is rotating forward, and the second position is not meshed with the transport gear when the transmission gear is reversely rotated. And a oscillating gear
The oscillating gear is
In one of the first position and the second position, drive is transmitted without passing through the reverse gear,
The toner replenishing device, wherein the drive is transmitted through the reverse gear at the other position of the first position and the second position. A toner replenishing device according to any one of claims 1 to 5,
The control unit determines the duration of the rotation of the agitating member after the toner supply operation from the toner container to the toner storage unit is completed if the toner container is not replaced. A toner replenishing device characterized in that the toner replenishing device is longer. A toner replenishing device according to any one of claims 1 to 6,
The control unit sets the duration of rotation of the stirring member after completion of the toner supply operation from the toner container to the toner storage unit, and the frequency of toner supply to the development process unit is higher than a predetermined level. In some cases, the toner replenishing device is longer than the other cases. A toner replenishing device according to any one of claims 1 to 7, comprising:
An image forming apparatus, wherein an image is formed on a medium by toner supplied from the toner supply device.

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