JP2013113893A - Developing device, and image forming apparatus including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize stable supply adjustment of supply developer in a case where a developer inlet is disposed downstream of a first conveyance path in a developer conveyance path in a developing device in which toner is supplied from a toner container in association with decrease in developer in a developer retaining unit.SOLUTION: A conveying capacity suppressing unit 26 forms a retaining unit 27 at a position facing a toner supply port 25. Depending on an amount of toner in the retaining unit 27, an amount of toner flowing into a developing housing 210 from a toner container 30 is adjusted. A first paddle 23c passes toner to a second conveyance path 222 from a first conveyance path 221. The toner excessively retained in the retaining unit 27 flows out to the second conveyance path 222 side from a gap where the conveyance capacity suppressing unit 26 and a first communication path 223 overlap with each other in an axial direction.

Description

  The present invention relates to a developing device suitably mounted on an image forming apparatus such as a copying machine or a printer, and an image forming apparatus including the developing device.

  Conventionally, a developing device as described in Patent Document 1 is known. The developing device includes a developing housing having a developing roller and a stirring screw, and a toner container for replenishing toner that is detachably attached to the developing housing. A toner discharge port that can be opened and closed is provided at the bottom of the toner container, and a toner supply port is provided at a position corresponding to the toner discharge port in the development housing. When the toner container is mounted on the developing housing and the toner discharge port and the toner replenishing port are opened, the toner in the toner container is supplied to a predetermined circulation conveyance path formed in the developing housing.

  The circulation conveyance path includes an outward conveyance path corresponding to the toner replenishing port and a backward conveyance path corresponding to the developing roller. Each circulation conveyance path is equipped with a stirring screw having spiral blades arranged around the rotation axis. The toner is circulated and conveyed between the forward conveyance path and the backward conveyance path by these stirring screws.

  In the developing device of Patent Document 1 having such a configuration, a transport capability suppressing unit configured to locally decrease the transport capability downstream of the toner supply port of the stirring screw provided in the forward transport path. Is provided. By such a conveyance capability suppression unit, a toner retention portion is formed in the vicinity of the toner supply port on the upstream side of the conveyance capability suppression unit. When the amount of toner in the staying portion is large, the toner in the staying portion blocks the toner supply port. When the amount of toner in the staying portion is small, a gap is generated between the toner supply port and the toner staying portion, and the toner flows into the developing housing from the toner container side. Thus, the toner replenishment amount to be replenished from the toner container to the developing housing is adjusted according to the toner amount staying in the staying portion.

JP-A-2005-346116

  In determining the layout in the apparatus main body on which the developing device described in Patent Document 1 is mounted, there are cases where it is desired to connect the toner container to the end of the developing housing in the direction of the rotation axis. In this case, the toner replenishing port is disposed at the end portion of the forward conveyance path, and since the communication path that connects the forward conveyance path and the return conveyance path is close to the end portion, the development port is originally developed. The agent tends to stay. Therefore, when the toner replenishing port is disposed at the end of the forward conveyance path, the retention of the developer in the vicinity of the communication path affects the retention part formed by the conveyance capacity suppression unit, and toner replenishment adjustment is not possible. The trouble of becoming stable arises.

  The present invention has been made in order to solve the above-described problems, and in the developing device in which the replenishment developer is replenished from the replenishment developer accommodating portion as the developer in the developer retention portion decreases. An object of the present invention is to provide a developing device capable of realizing a stable replenishment of developer even when the developer receiving port is disposed in the vicinity of the communication path in the developer transport path.

  A developing device according to an aspect of the present invention includes a housing that houses a developer, a replenishment developer housing portion that is detachable from the housing and houses a replenishment developer that is replenished to the housing, Within the housing, the developer is transported in a first transport path in the first direction and along the first transport path, and the developer is transported in a second direction opposite to the first direction. A second communication path, a first communication path communicating the downstream side of the first conveyance path and the upstream side of the second conveyance path toward a third direction intersecting the first direction, and the third direction. A developer transport path including a second communication path communicating the downstream side of the second transport path and the upstream side of the first transport path toward a fourth direction opposite to the first direction; The replenishment developer is disposed from the replenishment developer storage portion to the developer conveyance path. A developer receiving port that is inserted into the first transport path, and transports the developer in the first direction so that the developer receiving port passes through a position facing the first transport path. By disposing the developer conveying unit and the developer conveying port of the developer conveying unit in the first direction downstream from the first direction, and partially suppressing the developer conveying capability of the developer conveying unit, A developer retaining portion that adjusts the amount of the replenishment developer received is formed at a position facing the developer receiving port, and the downstream side in the first direction faces the first communication path in the third direction. A capacity suppressing section, and connected to the downstream side in the first direction of the transport capacity suppressing section of the developer transport section, and opposed to the first communication path in the third direction; Communicating transport that delivers the developer to the second transport path And having a, the.

  According to this configuration, the transport capability suppressing unit forms the developer retaining portion in the first transport path at a position facing the developer receiving port. When the amount of developer in the developer transport path is large, the developer retaining portion seals the opposing developer receiving port. For this reason, it is difficult for the replenishment developer to flow from the replenishment developer container to the housing side. On the other hand, when the amount of developer in the developer transport path is small, a gap is formed between the developer retaining portion and the developer receiving port, and the replenishment developer flows into the housing side from the replenishment developer accommodating portion. When the developer receiving port is disposed on the downstream side in the first direction of the first transport path, the transport capability suppressing portion and the first communication path are close to each other. For this reason, the retention of the developer transferred from the first conveyance path to the second conveyance path in the first communication path merges with the adjacent developer retention portion, which affects the inflow of the replenishment developer. Thus, even if it is the structure where a conveyance capability suppression part is arrange | positioned in the position close | similar to a 1st communicating path, the communication conveyance part connected with the 1st direction downstream of a conveyance capability suppression part is a 1st conveyance path. Therefore, it is difficult for the developer to be transferred to flow backward to the conveyance capability suppressing portion side. Furthermore, since the downstream side in the first direction of the conveyance capacity suppression unit faces the first communication path in the third direction, the conveyance capacity is suppressed even when the developer stays excessively in the vicinity of the conveyance capacity suppression unit. The developer around the part can flow directly into the first communication path without going through the communication conveyance part. For this reason, the excess developer in the developer retaining portion quickly flows out to the second transport path side. As a result, the retention of the developer in the developer retention portion is stabilized, and the replenishment amount of the replenishment developer is suitably adjusted.

  In the above configuration, it is preferable that the developer transport unit includes a rotation shaft and screw blades formed around the rotation shaft, and the developer is transported by rotation of the screw blades.

  According to this configuration, the developer is transported in the developer transport path by the screw blades formed around the rotation axis. The screw blades have a force for extruding the developer in the rotational radius direction in addition to the conveyance direction. For this reason, in the developer retention part formed by the conveyance capacity suppressing part, the developer can easily seal the developer receiving port by the rotational force of the screw blade.

  Said structure WHEREIN: It is preferable that the said 1st conveyance capability suppression part is formed by missing the said screw blade | wing.

  According to this configuration, the developer retaining portion is formed by a portion where the screw blade is missing. For this reason, compared with the case where the screw blades are arranged in the conveyance capability suppressing portion, the formation of the developer retention portion is less dependent on the rotation speed of the developer conveyance member. Therefore, even when the developer conveying member is rotationally driven at a plurality of rotational speeds, the developer retaining portion is formed, and the replenishment of the replenishment developer is stably adjusted. In addition, since the transport capability suppressing unit does not have the capability of transporting the developer in the first direction, the developer is prevented from being excessively retained between the transport capability suppressing unit and the communication transport unit.

  Said structure WHEREIN: It is preferable that the said communication conveyance part is a plate-shaped member arrange | positioned rotatably at the said rotating shaft.

  According to this configuration, the developer is positively transferred from the first conveyance path to the second conveyance path by the rotation of the plate-like member. For this reason, it is difficult for the developer to flow backward from the first communication path to the conveyance capability suppressing portion side, and the retention of the developer in the developer retention portion is easily stabilized. Further, since the rotating plate-like member forms a barrier at the boundary with the conveyance capacity suppressing portion, the stagnant developer necessary for the replenishment adjustment of the replenishment developer flows out excessively to the first communication path side. Is suppressed.

  In the above configuration, it is preferable that the following expression is satisfied. Z <X <B (Z: distance in the first direction from the downstream end in the first direction of the developer receiving port to the upstream end in the first direction of the first communication path, X: in the first direction) Length of the conveyance capacity suppressing part, B: width of the first communication path in the first direction).

  According to this configuration, a stable developer retention portion is formed by the communication conveyance portion and the conveyance capability suppression portion. At this time, the length in which the first communication path and the conveyance capability suppressing unit overlap in the first direction is set to be shorter than the length of the communication conveyance unit in the first direction. For this reason, a large amount of the developer staying in the developer staying portion does not flow out from the overlap portion into the first communication path. As a result, the excess developer in the developer retaining portion flows out to the second transport path side through the first communication path, and the developer amount in the developer retaining portion is stabilized.

  In the above configuration, it is preferable that the following formula is satisfied. B <A (A: width of the second communication path in the second direction, B: width of the first communication path in the first direction).

  According to this configuration, since the developer pressure is higher in the first communication path than in the second communication path, a large amount of developer is prevented from staying on the second communication path side. Therefore, it is possible to collect developer stagnation in the developer conveyance path in a region from the developer stagnation part to the first communication path.

  In addition, an image forming apparatus according to another aspect of the present invention includes an image carrier on which an electrostatic latent image is formed on a surface, and the electrostatic latent image is manifested in a developer image by the developer, And a developing device according to any one of the above.

  According to this configuration, in the image forming apparatus including the developing device in which the replenishment developer is replenished from the replenishment developer accommodating portion as the developer in the developer retention portion decreases, the developer receiving port is connected to the developer conveyance path. Even if the developer is disposed on the downstream side of the first conveying path, the developer staying around the first communication path hardly affects the developer staying portion, and stable replenishment of developer can be realized. For this reason, the developer concentration in the developing device is stabilized, and the image density can be stabilized.

  According to the present invention, in the developing device in which the replenishment developer is replenished from the replenishment developer accommodating portion as the developer in the developer retention portion decreases, the developer receiving port is connected to the first transport path in the developer transport path. Even in the case where it is disposed on the downstream side, it is possible to realize a stable replenishment of developer. Further, the developer density in the developing device is stabilized, and the image density can be stabilized.

1 is a schematic diagram illustrating an internal structure of an image forming apparatus according to an embodiment of the present invention. 1 is a plan view of a developing device according to an embodiment of the present invention. FIG. 3 is a cross-sectional view of a toner replenishing unit according to an embodiment of the present invention. It is a perspective view of a stirring screw concerning one embodiment of the present invention. 1 is a plan view of a developing device according to an embodiment of the present invention. It is a top view of the developing device concerning other embodiments of the present invention. It is a top view of the developing device concerning other embodiments of the present invention. It is a top view of the developing device concerning a comparative example. It is a top view of the developing device concerning a comparative example. It is a top view of the developing device concerning a comparative example. It is a top view of the conventional volume supply type developing device. It is a top view of the conventional volume supply type developing device.

  A developing device according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing a configuration of an image forming apparatus 1 including a developing device 20 according to an embodiment of the present invention. The image forming apparatus 1 includes an optical scanning device 11, a developing device 20, a toner container 30 (replenishment developer container), a charger 13, a photosensitive drum 14 (image carrier), a transfer roller 15, a fixing device 16, and a paper feed. A cassette 17 is provided.

  The photosensitive drum 14 is a cylindrical member, and an electrostatic latent image and a toner image are formed on the peripheral surface thereof. The photosensitive drum 14 receives a driving force from a motor (not shown) and rotates in the clockwise direction in FIG. The charger 13 charges the surface of the photosensitive drum 14 substantially uniformly.

  The optical scanning device 11 includes a light source such as a laser diode, a deflector, a scanning lens, an optical element, and the like. The optical scanning device 11 irradiates the peripheral surface (scanned surface) of the photosensitive drum 14 that is substantially uniformly charged by the charger 13 with a laser beam corresponding to the image data, thereby electrostatically charging the image data. A latent image is formed.

  The developing device 20 supplies toner to the peripheral surface of the photosensitive drum 14 on which the electrostatic latent image is formed to form a toner image. The developing device 20 includes a developing roller that carries toner and a stirring screw that stirs and conveys the toner. The toner image formed on the photosensitive drum 14 is transferred from the sheet feeding cassette 17 and transferred to the sheet conveyed through the conveyance path P. The developing device 20 is supplied with toner from a toner container 30. The developing device 20 will be described in detail later.

  The toner container 30 is a box-shaped member and stores toner therein. The toner container 30 supplies toner into the developing device 20. The toner container 30 is detachably disposed with respect to the developing device 20.

  A transfer roller 15 is disposed below the photosensitive drum 14 so as to face each other, and a transfer nip portion is formed by both. The transfer roller 15 is composed of a conductive rubber material or the like. The transfer roller 15 is applied with a transfer bias by a bias applying unit (not shown). The transfer roller 15 transfers the toner image formed on the photosensitive drum 14 onto the recording paper.

  The fixing device 16 includes a fixing roller 160 incorporating a heater and a pressure roller 161 provided at a position facing the fixing roller 160. The fixing device 16 fixes the toner image formed on the recording paper by heating and conveying the recording paper on which the toner image is formed.

<Description of developing device>
FIG. 2 is a plan view showing the internal structure of the developing device 20. The developing device 20 includes a developing housing 210 (housing) having a box shape elongated in one direction (the axial direction of the developing roller 21). The developing housing 210 has an internal space 220. In the internal space 220, the developing roller 21, the first stirring screw 23 (developer conveying unit), the second stirring screw 24, and the toner supply port 25 are disposed. In the case of the one-component development method, the internal space 220 is filled with toner as a developer. In the case of the two-component development method, a mixture of toner and a carrier made of a magnetic material is filled as a developer. The toner is agitated and conveyed in the internal space 220 and is sequentially supplied from the developing roller 21 to the photosensitive drum 14 in order to develop the electrostatic latent image.

  The developing roller 21 has a cylindrical shape that extends in the longitudinal direction of the developing housing 210 and has a sleeve portion that is rotationally driven on the outer periphery. In the case of the one-component development method, toner having a charge due to frictional charging adheres to the sleeve portion from the second stirring screw 24. In the case of the two-component development method, the magnetic carrier is attached to the sleeve surface from the second agitating screw 24 by the magnetic field formed by the magnetic pole fixedly arranged inside the sleeve together with the toner adhering by electrostatic force. Adhere to. The toner (developer) carried on the sleeve surface is conveyed to an opening (not shown) provided in the developing housing 210 and supplied to the opposing photosensitive drum 14.

  An inner space 220 of the developing housing 210 is covered with a top plate (not shown) and is partitioned into a first transport path 221 and a second transport path 222 that are long in the left-right direction by a partition plate 22 extending in the left-right direction. Yes. The partition plate 22 is shorter than the width of the developing housing 210 in the left-right direction, and a first communication path 223 and a first communication path 223 that respectively connect the first transport path 221 and the second transport path 222 to the left end and the right end of the partition plate 22. A double communication path 224 is provided. Accordingly, a circulation path (developer transport path) that reaches the first transport path 221, the first communication path 223, the second transport path 222, and the second communication path 224 is formed in the internal space 220. The toner is conveyed in the clockwise direction in FIG.

  The toner supply port 25 (developer receiving port) is an opening formed in the top plate, and is disposed above the vicinity of the left end of the first conveyance path 221 (FIG. 2). The toner replenishing port 25 is disposed so as to face the above-described circulation path, and has a function of receiving replenished toner (supplied developer) replenished from the toner container 30 into the internal space 220.

  The first stirring screw 23 is disposed in the first conveyance path 221. The first agitating screw 23 includes a first rotating shaft 23a (rotating shaft) and a first spiral blade 23b (screw blade) protruding in a spiral shape on the circumference of the first rotating shaft 23a. The first stirring screw 23 is driven to rotate around the first rotation shaft 23a (arrow R2), thereby conveying the toner in the direction of arrow D1 (first direction) in FIG. The first agitation screw 23 conveys the developer so that the toner replenishing port 25 passes through a position facing the first conveyance path 221. As a result, the first stirring screw 23 mixes the new toner flowing in from the toner replenishing port 25 and the toner transported through the first transport path 221, and delivers the mixed toner to the second transport path 222 side. It has a function. A first paddle 23c is disposed downstream of the first stirring screw 23 in the toner conveyance direction (D1 direction). The first paddle 23c is a plate-like member disposed on the first rotating shaft 23a. The first paddle 23c is rotated together with the first rotation shaft 23a, and delivers the toner from the first conveyance path 221 to the second conveyance path 222 in the direction of arrow D3 (third direction) in FIG.

  The second stirring screw 24 is disposed in the first conveyance path 222. The second agitating screw 24 includes a second rotating shaft 24a and a second spiral blade 24b protruding in a spiral shape on the circumference of the second rotating shaft 24a. The second agitating screw 24 is driven to rotate around the second rotation shaft 24a (arrow R1), thereby conveying the toner in the direction of arrow D2 (second direction) in FIG. The second stirring screw 24 transports toner in the second transport path 222 and supplies the toner to the developing roller 21. A second paddle 24c is disposed downstream of the second stirring screw 24 in the toner conveyance direction (D2 direction). The second paddle 24c is a plate-like member disposed on the second rotation shaft 24a. The second paddle 24c is rotated together with the second rotation shaft 24a, and delivers the toner from the second conveyance path 222 to the first conveyance path 221 in the direction of arrow D4 (fourth direction) in FIG.

  The toner container 30 is disposed above the toner supply port 25 of the developing housing 210. The toner container 30 includes a toner transport path 30 a through which toner is transported, a toner transport member 321, and a toner discharge port 33. In the toner container 30, the longitudinal direction of the toner container 30 (the direction in which the toner conveyance path 30 a is formed) is orthogonal to the longitudinal direction of the developing device 20 (the developer conveyance direction of the first stirring screw 23, the direction of the arrow D <b> 1). The developing device 20 is assembled so as to be positioned in the direction.

  The toner discharge port 33 is disposed at the bottom of the toner container 30 corresponding to the toner supply port 25 of the developing device 20. The toner conveying member 321 has a shaft portion and a blade portion that rotates around the shaft portion (see FIG. 3), and conveys the replenishment toner in the toner conveying path 30 a toward the toner discharge port 33. The toner dropped from the toner discharge port 33 is supplied to the developing device 20 through the toner supply port 25.

<About staying part>
Next, the flow of toner newly supplied from the toner supply port 25 will be described. FIG. 3 is a cross-sectional view of the vicinity of the toner supply port 25 provided in the developing device 20 and the toner discharge port 33 provided in the toner container 30. In FIG. 3, for the sake of explanation, the arrangement of the toner container 30 is shown rotated 90 degrees in the horizontal direction. Actually, the toner conveying member 321 in the toner container 30 extends toward the front of the sheet, and the first stirring screw 23 and the toner conveying member 321 in the toner container 30 are in a positional relationship orthogonal to each other. ing.

  The replenishment toner T2 supplied from the toner discharge port 33 of the toner container 30 falls into the first conveyance path 221 and is mixed with the existing toner T1, and is conveyed by the first agitating screw 23 in the direction of arrow D1 (first direction). Is done. At this time, the toners T1 and T2 are stirred and charged.

  The first agitating screw 23 includes a first conveyance capacity suppressing unit 26 that partially suppresses the developer conveyance performance downstream of the toner supply port 25 in the toner conveyance direction. In this embodiment, the 1st conveyance capability suppression part 26 is formed by missing the 1st spiral blade 23b of the 1st stirring screw 23 (refer FIG. 4). Therefore, the first transport capability suppressing portion corresponds to a portion where only the first rotating shaft 23a is partially disposed. In this case, the 1st conveyance capability suppression part 26 does not have the developer conveyance performance of the axial direction of the 1st rotating shaft 23a. Accordingly, the toner transported from the upstream side of the first transport capacity suppression unit 26 in the first transport path 221 starts to stay in the first transport capacity suppression unit 26. The retention of the toner is accumulated immediately upstream of the first conveyance capability suppressing unit 26 and the toner supply port 25 is accumulated to a position facing the first conveyance path 221. As a result, a developer retention portion 27 (developer retention portion) is formed in the vicinity of the inlet of the toner supply port 25.

  Note that, when the first stirring screw 23 of the developing device 20 is controlled at different rotational speeds according to the operating conditions of the image forming apparatus 1, as in the present embodiment, the first transport capability suppression unit 26 is It is preferable that the first spiral blade 23b is not provided and the first rotary shaft 23a is used alone. In this case, since the toner conveyance performance is suppressed without depending on the rotation speed of the first stirring screw 23, the staying portion 27 is stably formed.

  When the replenishment toner T2 is replenished from the toner replenishing port 25 and the amount of toner in the internal space 220 increases, the toner staying in the staying portion 27 closes (seals) the toner replenishing port 25, and more toner is added. Suppress supply. Thereafter, when the toner in the internal space 220 is consumed from the developing roller 21 and the toner staying in the staying portion 27 is reduced, the toner that has blocked the toner replenishing port 25 is reduced, and the space between the staying portion 27 and the toner replenishing port 25 is reduced. There is a gap in As a result, the replenishment toner T2 flows into the internal space 220 from the toner replenishment port 25 again. Thus, in the present embodiment, a volume replenishment type toner replenishment format is adopted in which the amount of replenishment toner received is adjusted as the amount of toner remaining in the retention portion 27 decreases.

  Conventionally, in a developing device having a volume replenishing type toner replenishing type, as shown in FIG. 11, the toner replenishing port 25 (25J1) is disposed at a substantially central portion in the axial direction in the first transport path 421. The staying part formed by the transporting capacity suppressing part 26J1 is formed on the first transporting path 421 facing the toner replenishing port 25J1, and the amount of replenishing toner supplied from the toner container 30 is adjusted by increasing or decreasing the staying part. It was.

  Here, when the layout in the main body of the image forming apparatus 1 on which the developing device is mounted is determined, the toner container 30 may be desired to be connected to the end of the developing housing 212 in the rotation axis direction. For example, as shown in FIG. 12, a toner replenishing port 25J2 is disposed at the upstream end of the first transport path 521 in the toner transport direction (arrow D11), and the toner container 30 faces the toner replenishment port 25J2. (Not shown) is arranged. In this case, the staying portion 27J2 is formed so as to face the toner replenishing port 25J2 by the transport capability suppressing portion 26J2.

  On the other hand, a communication path 502 that connects the first transport path 521 and the second transport path 522 is disposed at the upstream end of the first transport path 521 where the toner supply port 25J2 is disposed. The toner transferred from the second conveyance path 522 to the first conveyance path 521 is conveyed in the direction of the arrow D11 by the first conveyance member 23J2, and then collides with the staying portion 27J2. Therefore, the toner flow is hindered by the staying portion 27J2. As a result, toner clogging occurs in a region T in FIG.

  Therefore, as shown in FIG. 5, a toner replenishing port 25 is provided on the downstream side in the first direction (arrow D1 direction) in the first transport path 221, and a toner container 30 (not shown) corresponding to this position. ) May be considered. In this case, the staying portion 27 formed by the conveyance capability suppressing unit 26 is close to the first communication path 223 that transfers the toner from the first conveyance path 221 to the second conveyance path 222. When the first paddle 23c is not disposed, the toner conveyed in the first direction by the first agitating screw 23 collides with the side wall 210a of the developing housing 210 to form a stay. Then, the toner overflowing from the retention gradually passes through the first communication path 223, whereby the toner is delivered. Therefore, the toner staying at the delivery may affect the staying portion 27 that is close to the toner, so that the adjustment of the replenishment toner becomes unstable.

  As described above, in order to solve the problem caused to the staying portion 27 when the toner supply port 25 is disposed on the downstream side in the first direction (arrow D1 direction) in the first transport path 221, the present embodiment is implemented. In the embodiment, a device specific to the arrangement of the first paddle 23c and the conveyance capacity suppressing unit 26 is applied. Hereinafter, this point will be described in detail.

  FIG. 5 is a diagram illustrating the first embodiment in which the arrangement of the first paddle 23c and the conveyance capability suppressing unit 26 is suitably set. In the drawing, A represents the width of the second communication path 224 in the second direction, B represents the width of the first communication path 223 in the first direction, and C represents the length of the first paddle 23c in the first direction. Represents X represents the length of the conveyance capacity suppressing unit 26 in the first direction, and Z represents the first from the downstream end in the first direction of the toner supply port 25 to the upstream end in the first direction of the first communication path 223. Represents the distance in the direction.

  In this embodiment, the shape and arrangement of each member are set so that the above A, B, X, and Z satisfy the relational expression Z <X <B (FIG. 5). As a result, the downstream side in the first direction of the conveyance capacity suppressing part 26 and the first paddle 23c (communication conveyance part) made of a plate-like member are opposed to the first communication path 223 in the third direction (arrow D3 direction). It is arranged to do.

  The length C of the rotating first paddle 23c is included in the width B of the first communication path 223 in the first direction. For this reason, the toner positioned at the downstream end of the first conveyance path 221 receives the rotational force of the first paddle 23 c and is positively delivered to the upstream side of the second conveyance path 222. Therefore, the toner located at the downstream end of the first transport path 221 is prevented from flowing back around the transport capability suppressing unit 26.

  Further, the downstream side in the first direction of the conveyance capacity suppressing unit 26 faces the first communication path 223 in the third direction. For this reason, even if the toner stays excessively in the vicinity of the conveyance capability suppressing unit 26, the toner around the conveyance capability suppressing unit 26 does not pass through the first paddle 23c, as indicated by the arrow F1 in the figure. Then, it can flow directly into the first passage 223. For this reason, the excessive toner in the staying portion 27 quickly flows out to the second conveyance path 222 side. As a result, the toner staying in the staying portion 27 is stabilized, so that the replenishment amount of the replenishing toner is suitably adjusted.

  Further, since the first paddle 23c is composed of a plate-like member, the rotation of the first paddle 23c causes the right end portion (upstream end portion in the first direction) of the first paddle 23c and the conveyance capacity suppressing portion 26 to be connected. A barrier is formed between them. For this reason, the toner is easily dammed up, and the end (starting end) on the downstream side in the first direction of the staying portion 27 is surely secured, and the toner in the staying portion 27 necessary for supply toner replenishment adjustment. However, it is suppressed that it flows out to the 1st communicating path 223 side excessively.

  In the present embodiment, the length of the first paddle 23c is set so as to satisfy the relational expression C> (BC) (FIG. 5). As a result, the length (B-C) at which the first communication path 223 and the conveyance capacity suppressing unit 26 overlap in the first direction is set to be shorter than the length C of the first paddle 23c in the first direction. The For this reason, a large amount of toner staying in the staying portion 27 does not flow out from the overlap portion into the first communication path 223. As a result, only the excess toner in the staying part 27 flows out to the second transport path 222 side through the first communication path 223, and the toner amount in the staying part 27 is stabilized.

  Further, in the present embodiment, the widths in the first direction of the first communication path 223 and the second communication path 224 are respectively set so as to satisfy the relational expression B <A. As a result, compared with the second communication path 224, the toner pressure is higher in the first communication path 223, so that a large amount of toner is suppressed from staying on the second communication path 224 side. Therefore, the retention of toner in the circulation path can be collected in the region from the retention portion 27 to the first communication path 223.

  Next, a second embodiment of the present invention will be described with reference to FIG. As in the first embodiment, the present embodiment includes a conveyance capability suppression unit 26a on the downstream side in the first direction of the toner supply port 25, and a first paddle on the downstream side in the first direction of the conveyance capability suppression unit 26a. 231c. Further, the downstream portion in the first direction of the conveyance capacity suppressing portion 26a and the first paddle 231c are opposed to the first communication path 223a in the third direction. On the other hand, the present embodiment is different from the first embodiment in the relationship of B, C, X, and Z described above, so this point will be described in detail, and description of other points will be omitted.

  In the present embodiment, the shape and arrangement of each member are set so as to satisfy the relational expressions Z <B <X and C <B. In this case, compared with the first embodiment, (BC), which is an overlap portion in the first direction, between the first communication path 223a and the conveyance capability suppressing unit 26a is set to be large. For this reason, in the present embodiment, the toner around the conveyance capability suppressing part 26a easily flows into the first communication path 223a side, and the staying part 27a is not easily formed. In other words, if the toner in the staying portion 27a tends to stay excessively due to the fluidity or environmental conditions of the toner used, the toner tends to flow into the first communication path 223a. The replenishment adjustment is preferably realized.

  Next, a third embodiment of the present invention will be described with reference to FIG. As in the first embodiment, the present embodiment includes a transport capability suppression unit 26b on the downstream side in the first direction of the toner supply port 25, and a first paddle on the downstream side in the first direction of the transport capability suppression unit 26b. 232c. Further, the downstream portion in the first direction of the conveyance capacity suppressing portion 26b and the first paddle 232c face the first communication path 223b in the third direction. On the other hand, the present embodiment is different from the first embodiment in the relationship of B, C, X, and Z described above, so this point will be described in detail, and description of other points will be omitted.

  In the present embodiment, the shape and arrangement of each member are set so as to satisfy the relational expressions B <Z <X and C <B. In this case, as compared with the first embodiment, the conveyance capacity suppressing portion 26b is set longer in the first direction, and the staying portion 27b is also formed in a range longer in the first direction. And the overlap part in the 1st direction of the 1st communicating path 223b and the conveyance capability suppression part 26b is set small with respect to the length in the 1st direction of the retention part 27b. As a result, in this embodiment, the toner in the staying portion 27b is unlikely to flow into the first communication path 223b side. In other words, even if toner retention is difficult to be formed due to the fluidity of the toner used, environmental conditions, and the like, the retention portion 27b is formed by the conveyance capability suppressing unit 26b, and the replenishment toner replenishment adjustment is performed. It is suitably realized.

  Next, a first comparative example that does not have the configuration of the present invention will be described with reference to FIG. Similar to the first embodiment, this comparative example includes a conveyance capability suppression unit 26c on the downstream side in the first direction of the toner supply port 25, and the first direction downstream of the conveyance capability suppression unit 26c in the first direction. A paddle 233c is provided. On the other hand, the downstream portion in the first direction of the conveyance capacity suppressing portion 26c does not face the first communication path 223c in the third direction. In addition, this comparative example differs from the first embodiment in the relationship of B, C, X, and Z described above, so this point will be described in detail, and description of other points will be omitted.

  In this comparative example, the shape and arrangement of each member are set so as to satisfy the relational expressions B <X <Z and B <C. In this case, as described above, as compared with the first embodiment, the downstream portion in the first direction of the conveyance capacity suppressing portion 26c does not face the first communication path 223c in the third direction. Accordingly, the toner in the staying portion 27c cannot pass through the first communication path 223c without passing through the first paddle 233c. Further, the width B in the first direction of the first communication path 223c is set to be smaller than the length C in the first direction of the first paddle 233c. Therefore, in the region M in FIG. 8, there is a problem that the toner stays excessively. As a result, in this comparative example, a large amount of toner stays regardless of whether or not the replenishment toner is necessary, and thus replenishment adjustment of the replenishment toner is not suitably realized.

  Next, a second comparative example that does not have the configuration of the present invention will be described with reference to FIG. Similar to the first embodiment, this comparative example includes a conveyance capability suppression unit 26d on the downstream side in the first direction of the toner supply port 25, and the first direction downstream of the conveyance capability suppression unit 26d in the first direction. A paddle 234c is provided. Further, the downstream portion in the first direction of the conveyance capacity suppressing portion 26d does not face the first communication path 223d in the third direction. Since this comparative example differs from the first embodiment in the relationship of B, C, X, and Z described above, this point will be described in detail, and description of other points will be omitted.

  In this comparative example, the shape and arrangement of each member are set so as to satisfy the relational expressions X <B <Z and B <C. In this case, as described above, compared to the first embodiment, the downstream portion in the first direction of the conveyance capacity suppressing portion 26d does not face the first communication path 223d in the third direction. Accordingly, the toner in the staying portion 27d cannot pass through the first passage 223d without passing through the first paddle 234c. In addition, the length C in the first direction of the first paddle 234c is set to be longer than the width B in the first direction of the first passage 223d, and as a result, the transport capability suppressing portion 26d is set to be short. As a result, the portion (CB) in which the first paddle 234c protrudes in the second direction (arrow D2 direction) is longer than the first communication passage 223d, and the rotation of the portion causes the toner in the first conveyance path 221 to move. Flow in the first direction is impeded. Then, the toner in the circulation path concentrates around the first paddle 234c, and the toner in other areas decreases. For this reason, the toner replenishing port 25 is always sealed by the staying portion 27d, and the replenishing toner cannot flow into the first transport path 221. Further, in this state, if the image forming apparatus 1 continuously outputs an image with a high printing rate, the toner is partially insufficient on the developing roller 21 and an image quality defect occurs. As described above, in this comparative example, the replenishment adjustment of the replenishment toner is not suitably realized, the balance of the toner in the circulation path is lost, and the image quality defect occurs.

  Next, a third comparative example that does not have the configuration of the present invention will be described with reference to FIG. As in the first embodiment, this comparative example includes a conveyance capability suppression unit 26e on the downstream side in the first direction of the toner supply port 25, and the first direction downstream of the conveyance capability suppression unit 26e in the first direction. A paddle 235c is provided. Further, the downstream portion in the first direction of the conveyance capacity suppressing portion 26e does not face the first communication path 223e in the third direction. Since this comparative example differs from the first embodiment in the relationship of B, C, X, and Z described above, this point will be described in detail, and description of other points will be omitted.

  In this comparative example, the shape and arrangement of each member are set so as to satisfy the relational expressions X <Z <B and B <C. In this case, as described above, as compared with the first embodiment, the downstream portion in the first direction of the conveyance capacity suppressing portion 26e does not face the first communication path 223e in the third direction. Therefore, the toner in the staying portion 27e cannot pass through the first communication path 223e without passing through the first paddle 235c. In addition, the length C in the first direction of the first paddle 235c is set slightly longer than the width B in the first direction of the first communication path 223e, and the conveyance capability suppressing portion 26e is set to be short. As a result, the toner in the staying portion 27e formed by the transport capability suppressing portion 26e is small, and excessive supply toner flows into the first transport path 221. In addition, since the first paddle 235c has a shorter portion (C-B) protruding in the second direction (arrow D2) than the first communication path 223e, the first paddle 235c blocks the toner conveyed in the first direction. The stopping power is small. As a result, since there is no region where toner concentrates and stays in the circulation path, the amount of toner distributed throughout the circulation path increases. Therefore, the driving torque of the developing device 20h is increased. As described above, in this comparative example, the replenishment adjustment of the replenishment toner is not properly realized, the balance of the toner in the circulation path is lost, and the driving torque of the developing device 20h becomes defective.

  As described above, each of the above-described embodiments includes the conveyance capability suppression unit 26 (26a, 26b) on the downstream side in the first direction of the toner supply port 25, and the conveyance capability suppression unit 26 (26a, 26b) has the first one. A first paddle 23c (231c, 232c) is provided on the downstream side in one direction. Further, the downstream portion in the first direction of the conveyance capacity suppressing portion 26 (26a, 26b) and the first paddle 23c (231c, 232c) face the first communication path 223 (223a, 223b) in the third direction. doing. As a result, the toner stays stably in the staying portion 27 (27a, 27b), and the replenishment adjustment of the replenishing toner is suitably realized.

  The developing device 20 according to the embodiment of the present invention has been described above. However, the present invention is not limited to this, and for example, the following modified embodiment can be adopted.

  (1) In the above-described embodiment, the portion where the first spiral blade 23b of the first stirring screw 23 is omitted is the conveyance capacity suppressing unit 26. In addition, the first spiral blade 23b of the first stirring screw 23 is also used. A bar member parallel to the first rotating shaft 23 a may be disposed on the peripheral edge of the first and second portions, and the portion to which the bar member is attached may be the conveyance capacity suppressing unit 26. The sticking member attached to the first spiral blade 23 b suppresses the toner carrying capacity, and the toner stays in the first carrying path 221.

  (2) In the above-described embodiment, the staying portion 27 is formed on the downstream side in the first direction of the toner replenishing port 25 in order to realize the replenishment adjustment of the replenishing toner. However, the present invention is not limited to this. An upstream retention portion 29 may be formed on the upstream side in the first direction of the toner supply port. 5 to 7, a suppression paddle 28 is disposed on the first stirring screw 23 on the upstream side in the first direction of the toner supply port 25.

  The restraining paddle 28 is a plate-like rib member that extends between two first spiral blades 23b adjacent in the first direction (arrow D1 direction) and extends in the rotational radius direction of the first rotating shaft 23a. is there. The suppression paddle 28 is rotated in the direction of the arrow R <b> 2 in accordance with the rotation of the first stirring screw 23, and transports the toner transported in the first transport path 221 in the R <b> 2 direction. For this reason, the toner conveyance performance in the first direction is suppressed around the suppression paddle 28, and the toner stays. With this staying toner, an upstream staying portion 29 is formed in the first transport path 221 immediately upstream of the toner supply port 25. The upstream side retention portion 29 seals the upstream side in the first direction with respect to the toner replenishing port 25, so even if the fluidity of the toner in the toner container 30 attached to the developing device 20 is increased, The toner is prevented from flowing upstream of the toner supply port 25. Accordingly, the staying portion 27 (27a, 27b) is reliably formed at the start end portion located on the downstream side in the first direction by the rotation of the first paddle 23c (231c, 232c). A terminal portion located upstream in the direction is reliably formed.

  (3) Further, in the above-described embodiment, the plate-like member disposed on the first rotating shaft 23a is used as the first paddle 23c. However, the present invention is not limited to this. In other words, it may be a rod-like member disposed on the first rotating shaft 23a in parallel with the first rotating shaft 23a, and the tip of the plate-like member is bent into a square shape so that the toner The mode etc. which improved the delivery performance of may be sufficient.

20 Developing device 210 Developing housing (housing)
23 1st stirring screw (developer conveying part)
23a First rotating shaft (rotating shaft)
23b 1st spiral blade (screw blade)
23c, 231c, 232c First paddle (communication transport unit)
24 second stirring screw 24a second rotating shaft 24b second spiral blade 24c second paddle 25 toner supply port (developer receiving port)
26, 26a, 26b Conveyance capacity suppression unit 27, 27a, 27b Retention unit (developer retention unit)
28 Suppression paddle 29 Upstream side retention part 30 Toner container (replenishment developer storage part)
33 Toner outlet

Claims (7)

A housing for containing the developer;
A replenishment developer accommodating portion that is removably attached to the housing and houses a replenishment developer replenished to the housing;
Within the housing, the developer is disposed along the first transport path in which the developer is transported in the first direction, and the developer is disposed in a second direction opposite to the first direction. A second communication path that is conveyed, a first communication path that communicates the downstream side of the first conveyance path and the upstream side of the second conveyance path toward a third direction that intersects the first direction; A developer conveyance path including a second communication path that communicates the second conveyance path downstream side and the first conveyance path upstream side in a fourth direction opposite to the three directions;
A developer receiving port disposed in the casing so as to oppose a position on the downstream side in the first direction of the first conveyance path, and receiving the replenishment developer from the replenishment developer container into the developer conveyance path ,
A developer transport unit disposed in the first transport path and transporting the developer in the first direction so that the developer receiving port passes a position facing the first transport path;
The developer receiving port is disposed on the downstream side in the first direction from the developer receiving port of the developer conveying unit, and partially suppresses the developer conveying capability of the developer conveying unit, whereby the developer receiving port is A developer retention portion that adjusts the amount of the replenishment developer received at a position opposite thereto, and the downstream side in the first direction faces the first communication path in the third direction;
The developer conveying unit is connected to the downstream side in the first direction of the conveying capacity suppressing unit, and is opposed to the first communicating path in the third direction, from the first conveying path to the second conveying path. A developing device comprising: a communication transport unit that delivers the developer.   2. The developer transport unit according to claim 1, wherein the developer transport unit includes a rotation shaft and screw blades formed around the rotation shaft, and the developer is transported by rotation of the screw blades. Development device.   The developing device according to claim 2, wherein the conveyance capability suppressing unit is formed by missing the screw blade.   The developing device according to claim 2, wherein the communication conveyance unit is a plate-like member rotatably disposed on the rotation shaft. The developing device according to claim 2, wherein the following expression is satisfied.
Z <X <B
Z: distance in the first direction from the downstream end in the first direction of the developer receiving port to the upstream end in the first direction of the first communication path X: length of the transport capability suppressing portion in the first direction B: width of the first communication path in the first direction The developing device according to claim 2, wherein the following expression is satisfied.
B <A
A: Width of the second communication path in the second direction B: Width of the first communication path in the first direction An image carrier on which an electrostatic latent image is formed on the surface, and the electrostatic latent image is visualized into a developer image by the developer;
A developing device according to any one of claims 1 to 6,
An image forming apparatus comprising:

Images