JP6950235B2

JP6950235B2 - Transport equipment, developing equipment, and image forming equipment

Info

Publication number: JP6950235B2
Application number: JP2017064253A
Authority: JP
Inventors: 孝文若井
Original assignee: Fuji Xerox Co Ltd; Fujifilm Business Innovation Corp
Current assignee: Fujifilm Business Innovation Corp
Priority date: 2017-03-29
Filing date: 2017-03-29
Publication date: 2021-10-13
Anticipated expiration: 2037-03-29
Also published as: JP2018169418A

Description

本発明は、搬送装置、現像装置、及び画像形成装置に関する。 The present invention relates to a transport device, a developing device, and an image forming device.

特許文献１には、スパイラル状羽根部材を有し且つ現像剤を搬送する撹拌搬送部において、取り込み部のスパイラルピッチを撹拌部のスパイラルピッチより短くした構成が開示されている。 Patent Document 1 discloses a configuration in which the spiral pitch of the intake section is shorter than the spiral pitch of the stirring section in the stirring and transporting section having the spiral blade member and transporting the developer.

特開２００７−３０４２０２号公報JP-A-2007-304202

ここで、回転する軸部と、該軸部の外周面に螺旋状に形成された羽根と、を有する搬送部材で現像剤等の粉体を搬送する構成において、軸部の軸方向一部に大径部を形成して、大径部の搬送方向下流側へ搬送される粉体の単位回転数当りの搬送量を定量化したものがある。 Here, in a configuration in which a powder such as a developer is transported by a transport member having a rotating shaft portion and a blade formed spirally on the outer peripheral surface of the shaft portion, the shaft portion is partially in the axial direction. Some have formed a large-diameter portion and quantified the amount of powder transported to the downstream side in the transport direction of the large-diameter portion per unit rotation speed.

この構成では、軸部の回転数が上がると、大径部の上流側に粉体が滞留せず、大径部によって下流側への移動が制限される粉体の量が安定しないため、大径部の搬送方向下流側へ搬送される粉体の単位回転数当りの搬送量が変動する場合がある。 In this configuration, when the rotation speed of the shaft portion increases, the powder does not stay on the upstream side of the large diameter portion, and the amount of powder whose movement to the downstream side is restricted by the large diameter portion is not stable. The amount of powder transported to the downstream side in the transport direction of the diameter portion may fluctuate per unit rotation speed.

本発明は、大径部に対する直上流部分に形成された羽根の外径が、大径部に形成された羽根の外径と同じである構成に比べ、軸部の回転数が変化しても、大径部の搬送方向下流側へ搬送される粉体の単位回転数当りの搬送量の変動を抑制することを目的とする。 In the present invention, as compared with the configuration in which the outer diameter of the blade formed in the upstream portion with respect to the large diameter portion is the same as the outer diameter of the blade formed in the large diameter portion, even if the rotation speed of the shaft portion changes. The purpose is to suppress fluctuations in the amount of powder transported to the downstream side of the large-diameter portion in the transport direction per unit rotation speed.

請求項１の発明は、粉体が収容された筐体と、前記筐体の内部に配置され、軸方向の一部で大径とされた大径部を有する軸部と、前記大径部の外周面に螺旋状に形成され、前記軸部の回転により前記粉体を前記軸方向の一方へ搬送する第一羽根と、前記軸部における前記大径部に対する直上流部分の外周面に螺旋状に形成され、前記軸部の回転により前記粉体を前記一方へ搬送し、外径が前記第一羽根の外径よりも小さくされた第二羽根と、を備える。 The invention of claim 1 is a housing containing powder, a shaft portion arranged inside the housing and having a large diameter portion having a large diameter in a part in the axial direction, and the large diameter portion. The first blade, which is formed in a spiral shape on the outer peripheral surface of the shaft portion and conveys the powder in one direction in the axial direction by the rotation of the shaft portion, and the outer peripheral surface of the portion immediately upstream of the large diameter portion of the shaft portion. It is provided with a second blade which is formed in a shape and which conveys the powder to the one side by rotation of the shaft portion and whose outer diameter is smaller than the outer diameter of the first blade.

請求項３の発明では、前記第二羽根は、螺旋ピッチが前記第一羽根の螺旋ピッチよりも小さくされている。 In the invention of claim 3 , the spiral pitch of the second blade is smaller than the spiral pitch of the first blade.

請求項１の発明では、前記第二羽根は、条数が前記第一羽根の条数よりも少なくされている。 In the invention of claim 1 , the number of the second blade is smaller than the number of the first blade.

請求項２の発明では、前記筐体は、内壁が前記大径部において内側に張り出す張出部を有している。 In the invention of claim 2, the housing has an overhanging portion whose inner wall projects inward in the large-diameter portion.

請求項２の発明では、前記張出部の上流端面は、前記大径部の上流端面の上流側に配置されている。 In the invention of claim 2 , the upstream end face of the overhanging portion is arranged on the upstream side of the upstream end face of the large diameter portion.

請求項４の発明では、前記軸部における前記直上流部分に対する上流部分の外周面に螺旋状に形成され、前記軸部の回転により前記粉体を前記一方へ搬送し、外径が前記第二羽根の外径よりも大きくされた第三羽根、を備える。 In the invention of claim 4, the powder is spirally formed on the outer peripheral surface of the upstream portion of the shaft portion with respect to the immediate upstream portion, and the powder is conveyed to the one by rotation of the shaft portion, and the outer diameter is the second. A third blade, which is larger than the outer diameter of the blade, is provided.

請求項５の発明では、前記第三羽根は、螺旋ピッチが前記第二羽根の螺旋ピッチよりも大きくされている。 In the invention of claim 5 , the spiral pitch of the third blade is made larger than the spiral pitch of the second blade.

請求項６の発明では、前記第三羽根は、条数が前記第二羽根の条数よりも多くされている。 In the invention of claim 6, the number of rows of the third blade is larger than the number of rows of the second blade.

請求項７の発明は、粉体としての現像剤を搬送し、該現像剤で現像する。 In the invention of claim 7 , a developer as a powder is conveyed and developed with the developer.

請求項８の発明は、潜像を保持する保持体と、前記潜像を現像する請求項９に記載の現像装置と、前記現像装置によって現像された画像を記録媒体に転写する転写部と、を備える。 The invention of claim 8 comprises a retainer for holding a latent image, a developing device according to claim 9 for developing the latent image, and a transfer unit for transferring an image developed by the developing device to a recording medium. To be equipped.

本発明の請求項１の構成によれば、大径部に対する直上流部分に形成された第二羽根の外径が、大径部に形成された第一羽根の外径と同じである構成に比べ、軸部の回転数が変化しても、大径部の搬送方向下流側へ搬送される粉体の単位回転数当りの搬送量の変動を抑制できる。 According to the configuration of claim 1 of the present invention, the outer diameter of the second blade formed in the portion immediately upstream of the large diameter portion is the same as the outer diameter of the first blade formed in the large diameter portion. In comparison, even if the rotation speed of the shaft portion changes, it is possible to suppress fluctuations in the transport amount per unit rotation speed of the powder transported to the downstream side in the transport direction of the large diameter portion.

本発明の請求項３の構成によれば、第二羽根の螺旋ピッチが第一羽根の螺旋ピッチと同じである構成に比べ、軸部の回転数が変化しても、大径部の搬送方向下流側へ搬送される粉体の単位回転数当りの搬送量の変動を抑制できる。 According to the configuration of claim 3 of the present invention, as compared with the configuration in which the spiral pitch of the second blade is the same as the spiral pitch of the first blade, even if the rotation speed of the shaft portion changes, the transport direction of the large diameter portion Fluctuations in the amount of powder transported to the downstream side per unit rotation speed can be suppressed.

本発明の請求項１の構成によれば、第二羽根の条数が第一羽根の条数と同じである構成に比べ、軸部の回転数が変化しても、大径部の搬送方向下流側へ搬送される粉体の単位回転数当りの搬送量の変動を抑制できる。 According to the configuration of claim 1 of the present invention, as compared with the configuration in which the number of rows of the second blade is the same as the number of rows of the first blade, even if the rotation speed of the shaft portion changes, the transport direction of the large diameter portion It is possible to suppress fluctuations in the amount of powder transported to the downstream side per unit rotation speed.

本発明の請求項２の構成によれば、筐体の内壁が断面視にて直線状である構成に比べ、軸部の回転数が変化しても、大径部の搬送方向下流側へ搬送される粉体の単位回転数当りの搬送量の変動を抑制できる。 According to the configuration of claim 2 of the present invention, as compared with the configuration in which the inner wall of the housing is linear in cross-sectional view, even if the rotation speed of the shaft portion changes, the large-diameter portion is transported to the downstream side in the transport direction. It is possible to suppress fluctuations in the amount of conveyed powder per unit rotation speed.

本発明の請求項２の構成によれば、張出部の上流端面と軸部の大径部の上流端面とが同じ位置に配置される構成に比べ、軸部の回転数が変化しても、大径部の搬送方向下流側へ搬送される粉体の単位回転数当りの搬送量の変動を抑制できる。 According to the configuration of claim 2 of the present invention, even if the rotation speed of the shaft portion changes, as compared with the configuration in which the upstream end surface of the overhanging portion and the upstream end surface of the large diameter portion of the shaft portion are arranged at the same position. , It is possible to suppress fluctuations in the amount of powder transported to the downstream side in the transport direction of the large-diameter portion per unit rotation speed.

本発明の請求項４の構成によれば、第三羽根の外径が第二羽根の外径と同じである構成に比べ、軸部の回転数が変化しても、大径部の搬送方向下流側へ搬送される粉体の単位回転数当りの搬送量の変動を抑制できる。 According to the configuration of claim 4 of the present invention, as compared with the configuration in which the outer diameter of the third blade is the same as the outer diameter of the second blade, even if the rotation speed of the shaft portion changes, the transport direction of the large diameter portion Fluctuations in the amount of powder transported to the downstream side per unit rotation speed can be suppressed.

本発明の請求項５の構成によれば、第三羽根の螺旋ピッチが第二羽根の螺旋ピッチと同じである構成に比べ、軸部の回転数が変化しても、大径部の搬送方向下流側へ搬送される粉体の単位回転数当りの搬送量の変動を抑制できる。 According to the configuration of claim 5 of the present invention, as compared with the configuration in which the spiral pitch of the third blade is the same as the spiral pitch of the second blade, even if the rotation speed of the shaft portion changes, the transport direction of the large diameter portion Fluctuations in the amount of powder transported to the downstream side per unit rotation speed can be suppressed.

本発明の請求項６の構成によれば、第三羽根の条数が第二羽根の条数と同じである構成に比べ、軸部の回転数が変化しても、大径部の搬送方向下流側へ搬送される粉体の単位回転数当りの搬送量の変動を抑制できる。 According to the configuration of claim 6 of the present invention, as compared with the configuration in which the number of rows of the third blade is the same as the number of rows of the second blade, even if the rotation speed of the shaft portion changes, the transport direction of the large diameter portion It is possible to suppress fluctuations in the amount of powder transported to the downstream side per unit rotation speed.

本発明の請求項７の構成によれば、第二羽根の外径が第一羽根の外径と同じである構成に比べ、単位回転数当りの搬送量の変動に起因する現像不良を抑制できる。 According to the configuration of claim 7 of the present invention, development defects due to fluctuations in the transport amount per unit rotation speed can be suppressed as compared with the configuration in which the outer diameter of the second blade is the same as the outer diameter of the first blade. ..

本発明の請求項８の構成によれば、第二羽根の外径が第一羽根の外径と同じである構成に比べ、現像不良に起因する画像不良を抑制できる。 According to the configuration of claim 8 of the present invention, image defects due to development defects can be suppressed as compared with the configuration in which the outer diameter of the second blade is the same as the outer diameter of the first blade.

本実施形態に係る画像形成装置の構成を示す概略図である。It is the schematic which shows the structure of the image forming apparatus which concerns on this embodiment. 本実施形態に係る現像装置の構成を示す側断面図である。It is a side sectional view which shows the structure of the developing apparatus which concerns on this embodiment. 本実施形態に係る現像装置の構成を示す平断面図である。It is a plan sectional view which shows the structure of the developing apparatus which concerns on this embodiment. 本実施形態に係る搬送部材の一部を拡大して示す平面図である。It is a top view which shows the part of the transport member which concerns on this embodiment in an enlarged manner. 第一変形例に係る現像装置の構成を示す平断面図である。It is a plan sectional view which shows the structure of the developing apparatus which concerns on the 1st modification.

以下に、本発明に係る実施形態の一例を図面に基づき説明する。なお、図中に示す矢印Ｈは、装置上方（鉛直上方）を示している。 Hereinafter, an example of the embodiment according to the present invention will be described with reference to the drawings. The arrow H shown in the figure indicates the upper side (vertically upper side) of the device.

（画像形成装置１０の構成）
まず、画像形成装置１０の構成を説明する。図１は、画像形成装置１０の構成を示す概略図である。 (Structure of image forming apparatus 10)
First, the configuration of the image forming apparatus 10 will be described. FIG. 1 is a schematic view showing the configuration of the image forming apparatus 10.

画像形成装置１０は、図１に示されるように、各構成部品が内部に収容された装置本体１１（筐体）を備えている。装置本体１１の内部には、用紙等の記録媒体Ｐが収容される収容部１２と、記録媒体Ｐに画像を形成する画像形成部１４と、画像形成部１４によって記録媒体Ｐに形成された画像を当該記録媒体Ｐに定着する定着装置５６と、収容部１２から画像形成部１４へ記録媒体Ｐを搬送する搬送部１６と、画像形成装置１０の各部の動作を制御する制御部２０と、が設けられている。また、装置本体１１の上部には、定着装置５６によって画像が定着された記録媒体Ｐが排出される排出部１８が設けられている。 As shown in FIG. 1, the image forming apparatus 10 includes an apparatus main body 11 (housing) in which each component is housed. Inside the apparatus main body 11, there is an accommodating portion 12 in which a recording medium P such as paper is housed, an image forming unit 14 that forms an image on the recording medium P, and an image formed on the recording medium P by the image forming unit 14. The fixing device 56 for fixing the image to the recording medium P, the transport unit 16 for transporting the recording medium P from the accommodating unit 12 to the image forming unit 14, and the control unit 20 for controlling the operation of each unit of the image forming device 10. It is provided. Further, an discharge unit 18 is provided on the upper part of the device main body 11 to discharge the recording medium P on which the image is fixed by the fixing device 56.

画像形成部１４は、画像（潜像）を保持する感光体ドラム３２（保持体の一例）を有している。感光体ドラム３２は、一方向（例えば、図１における反時計回り方向）へ回転するようになっている。感光体ドラム３２の周囲には、感光体ドラム３２の回転方向上流側から順に、感光体ドラム３２を帯電させる帯電装置としての帯電ロール２３と、帯電ロール２３によって帯電した感光体ドラム３２を露光して感光体ドラム３２に静電潜像を形成する露光装置３６と、露光装置３６によって感光体ドラム３２に形成された静電潜像を現像して黒色のトナー画像を形成する現像装置６０（搬送装置の一例）と、現像装置６０によって感光体ドラム３２に形成された黒色のトナー画像を記録媒体Ｐに転写する転写部の一例としての転写ロール２６と、が設けられている。なお、現像装置６０の具体的な構成は後述する。 The image forming unit 14 has a photoconductor drum 32 (an example of a holding body) that holds an image (latent image). The photoconductor drum 32 rotates in one direction (for example, in the counterclockwise direction in FIG. 1). Around the photoconductor drum 32, a charging roll 23 as a charging device for charging the photoconductor drum 32 and a photoconductor drum 32 charged by the charging roll 23 are exposed in this order from the upstream side in the rotation direction of the photoconductor drum 32. An exposure device 36 that forms an electrostatic latent image on the photoconductor drum 32, and a developing device 60 that develops the electrostatic latent image formed on the photoconductor drum 32 by the exposure device 36 to form a black toner image (conveyed). An example of the apparatus) and a transfer roll 26 as an example of a transfer unit that transfers a black toner image formed on the photoconductor drum 32 by the developing apparatus 60 to the recording medium P are provided. The specific configuration of the developing device 60 will be described later.

露光装置３６は、制御部２０から送られた画像信号に基づき静電潜像を形成するようになっている。制御部２０から送られる画像信号としては、例えば、制御部２０が外部装置から取得した画像信号がある。 The exposure apparatus 36 forms an electrostatic latent image based on the image signal sent from the control unit 20. As the image signal sent from the control unit 20, for example, there is an image signal acquired by the control unit 20 from an external device.

装置本体１１の内部には、現像装置６０へ供給されるトナーを収容するトナーカートリッジ２９が設けられている。 Inside the apparatus main body 11, a toner cartridge 29 for accommodating toner to be supplied to the developing apparatus 60 is provided.

転写ロール２６は、感光体ドラム３２に対して接触している。転写ロール２６と感光体ドラム３２との間には、記録媒体Ｐを挟むニップ領域Ｔが形成されている。転写ロール２６は、ニップ領域Ｔにおいて記録媒体Ｐを感光体ドラム３２とで挟んで上側へ搬送し、ニップ領域Ｔにおいて記録媒体Ｐに対して、感光体ドラム３２に形成されたトナー画像を転写するようになっている。すなわち、ニップ領域Ｔが、感光体ドラム３２に形成されたトナー画像が記録媒体Ｐに転写される転写位置とされている。 The transfer roll 26 is in contact with the photoconductor drum 32. A nip region T that sandwiches the recording medium P is formed between the transfer roll 26 and the photoconductor drum 32. The transfer roll 26 sandwiches the recording medium P with the photoconductor drum 32 in the nip region T and conveys it upward, and transfers the toner image formed on the photoconductor drum 32 to the recording medium P in the nip region T. It has become like. That is, the nip region T is a transfer position where the toner image formed on the photoconductor drum 32 is transferred to the recording medium P.

搬送部１６は、収容部１２に収容された記録媒体Ｐを送り出す送出ロール４６と、送出ロール４６によって送り出された記録媒体Ｐが搬送される搬送路４８と、搬送路４８に沿って設けられ送出ロール４６によって送り出された記録媒体Ｐをニップ領域Ｔへ搬送する複数の搬送ロール対５０と、を備えている。 The transport unit 16 is provided along the delivery roll 46 that sends out the recording medium P housed in the storage unit 12, the transport path 48 through which the recording medium P sent out by the delivery roll 46 is transported, and the transport path 48, and sends out. It includes a plurality of transport roll pairs 50 that transport the recording medium P delivered by the roll 46 to the nip region T.

定着装置５６では、記録媒体Ｐを加熱及び加圧することで、転写ロール２６によって記録媒体Ｐに転写されたトナー画像を、当該記録媒体Ｐへ定着するようになっている。この定着装置５６の上方側（搬送方向下流側）には、トナー画像が定着された記録媒体Ｐを排出部１８へ排出する排出ロール５２が設けられている。 In the fixing device 56, the toner image transferred to the recording medium P by the transfer roll 26 is fixed to the recording medium P by heating and pressurizing the recording medium P. An discharge roll 52 for discharging the recording medium P on which the toner image is fixed to the discharge unit 18 is provided on the upper side (downstream side in the transport direction) of the fixing device 56.

（現像装置６０の構成）
次に、現像装置６０（搬送装置の一例）の構成を説明する。図２及び図３は、現像装置６０の構成を示す側断面図及び平断面図である。 (Structure of developing device 60)
Next, the configuration of the developing device 60 (an example of the transport device) will be described. 2 and 3 are a side sectional view and a plan sectional view showing the configuration of the developing apparatus 60.

現像装置６０は、図２に示されるように、トナー及び磁性キャリアからなる現像剤Ｇ（粉体の一例）が収容された筐体６２を有している。筐体６２には、感光体ドラム３２側に向かって開口する開口部６６が形成されている。この開口部６６から一部が露出するように、感光体ドラム３２へ現像剤Ｇを供給する現像剤供給体としての現像ロール６５が筐体６２内に設けられている。 As shown in FIG. 2, the developing apparatus 60 has a housing 62 in which a developing agent G (an example of powder) composed of toner and a magnetic carrier is housed. The housing 62 is formed with an opening 66 that opens toward the photoconductor drum 32 side. A developing roll 65 as a developing agent supplier for supplying the developing agent G to the photoconductor drum 32 is provided in the housing 62 so that a part of the opening 66 is exposed.

現像ロール６５は、現像剤Ｇ中に含まれた磁性キャリアを磁力で保持し、表面に現像剤Ｇの磁気ブラシを形成し、当該現像剤Ｇを感光体ドラム３２と対向する対向位置へ搬送するようになっている。当該対向位置へ向かって搬送される現像剤Ｇは、層規制部材６３によって、現像剤Ｇの層の厚さ（現像剤量）が規制される。そして、感光体ドラム３２上に形成された静電潜像が、現像ロール６５上の現像剤Ｇ（トナー）によってトナー画像として可視化される。 The developing roll 65 magnetically holds the magnetic carriers contained in the developing agent G, forms a magnetic brush of the developing agent G on the surface, and conveys the developing agent G to a position facing the photoconductor drum 32. It has become like. The layer thickness (amount of developer) of the developer G is regulated by the layer regulating member 63 of the developer G transported toward the facing position. Then, the electrostatic latent image formed on the photoconductor drum 32 is visualized as a toner image by the developer G (toner) on the developing roll 65.

図３に示されるように、筐体６２の内部における現像ロール６５側（＋Ｙ方向側）には、現像剤Ｇを搬送しながら現像ロール６５へ現像剤Ｇを供給するための供給路６８が、現像ロール６５の軸方向（Ｘ方向）に沿って形成されている。 As shown in FIG. 3, on the developing roll 65 side (+ Y direction side) inside the housing 62, a supply path 68 for supplying the developing agent G to the developing roll 65 while conveying the developing agent G is provided. It is formed along the axial direction (X direction) of the developing roll 65.

供給路６８には、供給路６８の一端側（＋Ｘ方向端側）から他端側（−Ｘ方向端側）へ向けて現像剤Ｇを搬送する搬送部材８０が配置されている。搬送部材８０は、軸部８２と、軸部８２の外周面に軸部８２の軸周りに螺旋状に形成された二条の羽根８３、８４と、を有している。 In the supply path 68, a transport member 80 for transporting the developer G from one end side (+ X direction end side) to the other end side (−X direction end side) of the supply path 68 is arranged. The transport member 80 has a shaft portion 82 and two blades 83, 84 spirally formed around the axis of the shaft portion 82 on the outer peripheral surface of the shaft portion 82.

軸部８２の軸方向両端部は、筐体６２の側壁６２Ａ、６２Ｂに回転可能に支持されている。軸部８２の一端部（＋Ｘ方向端部）には、駆動源６１からの回転力が伝達されるギヤ（図示省略）が固定されている。これにより、軸部８２は、図２の矢印Ｂ方向（時計回り方向）に回転するようになっている。 Both ends of the shaft portion 82 in the axial direction are rotatably supported by the side walls 62A and 62B of the housing 62. A gear (not shown) to which the rotational force from the drive source 61 is transmitted is fixed to one end (+ X direction end) of the shaft portion 82. As a result, the shaft portion 82 rotates in the arrow B direction (clockwise direction) in FIG.

二条の羽根８３、８４は、軸部８２の回転により、軸部８２の軸方向の一方側（−Ｘ方向側）を向く搬送面で現像剤Ｇを押しながら、当該現像剤Ｇを軸方向の一方（−Ｘ方向）へ搬送するようになっている。これにより、現像剤Ｇ中のトナーと磁性キャリアとが攪拌されながら軸方向の一方（−Ｘ方向）へ搬送される。 The two blades 83, 84 push the developer G on the transport surface facing one side (−X direction side) of the shaft portion 82 in the axial direction due to the rotation of the shaft portion 82, and push the developer G in the axial direction. It is designed to be transported in one direction (-X direction). As a result, the toner in the developer G and the magnetic carrier are conveyed in one axial direction (−X direction) while being agitated.

供給路６８に対する現像ロール６５側とは反対側（−Ｙ方向側）には、供給路６８で搬送された現像剤Ｇを供給路６８の搬送方向（−Ｘ方向）とは反対方向（＋Ｘ方向）へ向かって搬送する搬送路６９が設けられている。搬送路６９は、軸方向両端部（搬送方向上流端部及び下流端部）において、供給路６８と通じており、搬送路６９と供給路６８とで現像剤Ｇの循環経路を構成している。搬送路６９と供給路６８とは、その搬送方向（Ｘ方向）の中間部において仕切壁６７によって仕切られている。搬送路６９及び供給路６８は、＋Ｙ方向に沿った路幅がＸ方向に一定とされている。 On the side opposite to the developing roll 65 side (−Y direction side) with respect to the supply path 68, the developer G conveyed in the supply path 68 is placed in the direction opposite to the transfer direction (−X direction) of the supply path 68 (+ X direction). ) Is provided. The transport path 69 communicates with the supply path 68 at both ends in the axial direction (upstream end and downstream end in the transport direction), and the transport path 69 and the supply path 68 form a circulation path for the developer G. .. The transport path 69 and the supply path 68 are partitioned by a partition wall 67 at an intermediate portion in the transport direction (X direction). The width of the transport path 69 and the supply path 68 along the + Y direction is constant in the X direction.

搬送路６９には、搬送路６９の一端側（−Ｘ方向端側）から他端側（＋Ｘ方向端側）へ向けてトナーを搬送する搬送部材９０が配置されている。搬送部材９０は、軸方向の一部で大径とされた大径部９２Ａを有する軸部９２を備えている。 In the transport path 69, a transport member 90 that transports toner from one end side (end side in the −X direction) to the other end side (end side in the + X direction) of the transport path 69 is arranged. The transport member 90 includes a shaft portion 92 having a large diameter portion 92A having a large diameter in a part in the axial direction.

図４に示されるように、軸部９２が大径部９２Ａで径方向外側に張り出すことで、大径部９２Ａにおける搬送方向の上流端及び下流端のそれぞれには、−Ｘ方向側を向く上流端面９２Ｅと、＋Ｘ方向側を向く下流端面９２Ｆが形成されている。 As shown in FIG. 4, the shaft portion 92 projects outward in the radial direction at the large diameter portion 92A, so that each of the upstream end and the downstream end in the transport direction of the large diameter portion 92A faces the −X direction side. An upstream end face 92E and a downstream end face 92F facing the + X direction side are formed.

軸部９２における大径部９２Ａよりも搬送方向下流側（＋Ｘ方向側）の外周面には、図３に示されるように、軸部９２の軸周りに螺旋状とされた二条の羽根９３、９４と、軸部９２の径方向外側へ突出する突出部９２４と、が形成されている。 As shown in FIG. 3, on the outer peripheral surface of the shaft portion 92 on the downstream side (+ X direction side) of the large diameter portion 92A, the two blades 93 spirally formed around the axis of the shaft portion 92, A 94 and a protruding portion 924 protruding outward in the radial direction of the shaft portion 92 are formed.

羽根９３、９４は、それぞれ、軸部９２の軸方向に複数（例えば、６個）配置されている。各羽根９３、９４は、例えば、軸部９２の周方向に３６０度の範囲（１ピッチの範囲）で形成されている。 A plurality (for example, 6) of the blades 93 and 94 are arranged in the axial direction of the shaft portion 92, respectively. Each of the blades 93 and 94 is formed, for example, in a range of 360 degrees (a range of one pitch) in the circumferential direction of the shaft portion 92.

突出部９２４は、軸部９２の径方向外側（図３の＋Ｙ方向側）とその反対側（図３の−Ｙ方向側）とに突出する一対で構成されている。この一対の突出部９２４は、軸部９２の軸方向に接近して配置された２組が、軸部９２の軸方向に間隔をおいて複数（例えば、３つ）配置されている。 The protruding portion 924 is composed of a pair of protruding portions 924 on the radial side (+ Y direction side in FIG. 3) and the opposite side (−Y direction side in FIG. 3) of the shaft portion 92. In the pair of protruding portions 924, two sets arranged close to the axial direction of the shaft portion 92 are arranged in a plurality (for example, three) at intervals in the axial direction of the shaft portion 92.

軸部９２の搬送方向下流端部（＋Ｘ方向端部）の外周面には、羽根９３、９４とは逆巻きの螺旋状とされた一条の羽根９５が形成されている。 On the outer peripheral surface of the downstream end portion (+ X direction end portion) of the shaft portion 92 in the transport direction, a single blade 95 having a spiral shape opposite to that of the blades 93 and 94 is formed.

軸部９２の大径部９２Ａの外周面には、軸部９２の軸周りに螺旋状とされた二条の羽根９６、９７（第一羽根の一例）が形成されている。羽根９６、９７は、羽根９３、９４と同じ巻方向とされた螺旋状とされている。各羽根９６、９７は、例えば、軸部９２の周方向に３６０度の範囲（１ピッチの範囲）で形成されている。なお、本実施形態では、羽根９６、９７の１ピッチの軸方向の長さと、大径部９２Ａの軸方向長さとが同じとされている。 Two blades 96 and 97 (an example of the first blade) spirally formed around the shaft of the shaft portion 92 are formed on the outer peripheral surface of the large diameter portion 92A of the shaft portion 92. The blades 96 and 97 have a spiral shape having the same winding direction as the blades 93 and 94. Each of the blades 96 and 97 is formed, for example, in a range of 360 degrees (a range of one pitch) in the circumferential direction of the shaft portion 92. In the present embodiment, the axial length of one pitch of the blades 96 and 97 and the axial length of the large diameter portion 92A are the same.

図４に示されるように、軸部９２における大径部９２Ａに対する直上流部分９２Ｂの外周面には、軸部９２の軸周りに螺旋状とされた一条の羽根９１（第二羽根の一例）が形成されている。羽根９１は、羽根９６、９７と同じ巻方向とされた螺旋状とされている。羽根９１は、例えば、軸部９２の周方向に７２０度の範囲（２ピッチの範囲）で形成されている。また、羽根９１は、羽根９６、９７の上流側の最も近い位置に配置された羽根であり、羽根９６、９７に対して軸方向に連続して形成されている。なお、羽根９１は、羽根９６、９７に対して、軸方向に隙間を有して（離れて）いてもよい。この隙間は、現像剤Ｇの搬送が阻害されず、現像剤Ｇの溜まりができない程度の隙間とされる。具体的には、当該隙間は、例えば、羽根９１の１ピッチ以内に収まる隙間であればよい。 As shown in FIG. 4, on the outer peripheral surface of the upstream portion 92B of the shaft portion 92 with respect to the large diameter portion 92A, a single blade 91 spirally formed around the axis of the shaft portion 92 (an example of the second blade). Is formed. The blade 91 has a spiral shape having the same winding direction as the blades 96 and 97. The blade 91 is formed, for example, in a range of 720 degrees (a range of 2 pitches) in the circumferential direction of the shaft portion 92. Further, the blade 91 is a blade arranged at the closest position on the upstream side of the blades 96 and 97, and is formed continuously in the axial direction with respect to the blades 96 and 97. The blade 91 may have (separately) a gap in the axial direction with respect to the blades 96 and 97. This gap is set so that the transport of the developer G is not hindered and the developer G cannot be accumulated. Specifically, the gap may be, for example, a gap that fits within one pitch of the blade 91.

ここで、直上流部分９２Ｂは、大径部９２Ａに対する現像剤Ｇの搬送方向の上流側に大径部９２Ａに連続して設けられた軸部９２の一部分である。また、直上流部分９２Ｂは、大径部９２Ａに対する搬送方向の上流側の部分の一部の範囲に設定される。 Here, the immediately upstream portion 92B is a part of the shaft portion 92 continuously provided on the large diameter portion 92A on the upstream side in the transport direction of the developer G with respect to the large diameter portion 92A. Further, the immediate upstream portion 92B is set to a part range of the portion on the upstream side in the transport direction with respect to the large diameter portion 92A.

軸部９２における直上流部分９２Ｂに対する上流部分９２Ｃの外周面には、軸部９２の軸周りに螺旋状とされた二条の羽根９８、９９（第三羽根の一例）が形成されている。羽根９８、９９は、羽根９１と同じ巻方向とされた螺旋状とされている。羽根９８、９９は、例えば、軸部９２の周方向に７２０度の範囲（２ピッチの範囲）で形成されている。なお、上流部分９２Ｃは、本実施形態において、直上流部分９２Ｂの上流側に直上流部分９２Ｂに連続して設けられた軸部９２の一部分である。 Two blades 98 and 99 (an example of a third blade) spirally formed around the axis of the shaft portion 92 are formed on the outer peripheral surface of the upstream portion 92C with respect to the immediately upstream portion 92B of the shaft portion 92. The blades 98 and 99 have a spiral shape having the same winding direction as the blade 91. The blades 98 and 99 are formed, for example, in a range of 720 degrees (a range of 2 pitches) in the circumferential direction of the shaft portion 92. The upstream portion 92C is a part of the shaft portion 92 provided continuously to the direct upstream portion 92B on the upstream side of the direct upstream portion 92B in the present embodiment.

軸部９２の軸方向両端部は、図３に示されるように、筐体６２の側壁６２Ａ、６２Ｂに回転可能に支持されている。軸部９２の一端部（＋Ｘ方向端部）には、駆動源６１からの回転力が伝達されるギヤ（図示省略）が固定されている。これにより、軸部９２は、図２の矢印Ｆ方向（反時計回り方向）に回転するようになっている。 As shown in FIG. 3, both ends of the shaft portion 92 in the axial direction are rotatably supported by the side walls 62A and 62B of the housing 62. A gear (not shown) to which the rotational force from the drive source 61 is transmitted is fixed to one end (+ X direction end) of the shaft portion 92. As a result, the shaft portion 92 rotates in the arrow F direction (counterclockwise direction) in FIG.

羽根９１、９３、９４、９６、９７、９８、９９は、軸部９２の回転により、軸部９２の軸方向の一方側（＋Ｘ方向側）を向く搬送面で現像剤Ｇを押しながら、当該現像剤Ｇを軸方向の一方（＋Ｘ方向）へ搬送するようになっている。これにより、現像剤Ｇ中のトナーと磁性キャリアとが攪拌されながら軸方向の一方（＋Ｘ方向）へ搬送される。また、軸部９２の回転により、軸部９２の径方向外側へ突出する各突出部９２４によっても現像剤Ｇが撹拌される。 The blades 91, 93, 94, 96, 97, 98, 99 are said to be the same while pushing the developer G on the transport surface facing one side (+ X direction side) of the shaft portion 92 in the axial direction due to the rotation of the shaft portion 92. The developer G is conveyed in one axial direction (+ X direction). As a result, the toner in the developer G and the magnetic carrier are conveyed in one axial direction (+ X direction) while being agitated. Further, due to the rotation of the shaft portion 92, the developer G is also agitated by each of the protruding portions 924 protruding outward in the radial direction of the shaft portion 92.

一方、羽根９５は、軸部９２の回転により、軸部９２の軸方向の他方側（−Ｘ方向側）を向く搬送面で現像剤Ｇを押しながら、現像剤Ｇを軸方向の他方（−Ｘ方向）へ搬送するようになっている。これにより、搬送路６９内の搬送方向下流端部（＋Ｘ方向端部）に現像剤Ｇが詰まるのを抑制し、かつ、搬送路６９から供給路６８への現像剤Ｇの流入が促進される。なお、搬送部材８０の軸部８２の搬送方向下流端部（−Ｘ方向端部）の外周面にも、羽根８３、８４とは逆巻きの螺旋状とされた羽根を形成してもよい。 On the other hand, the blade 95 pushes the developer G on the transport surface facing the other side (−X direction side) of the shaft portion 92 in the axial direction due to the rotation of the shaft portion 92, while pushing the developer G on the other side (−X direction) in the axial direction. It is designed to be transported in the X direction). As a result, the developer G is suppressed from being clogged at the downstream end (+ X direction end) in the transport direction in the transport path 69, and the inflow of the developer G from the transport path 69 to the supply path 68 is promoted. .. It should be noted that the outer peripheral surface of the downstream end portion (−X direction end portion) of the shaft portion 82 of the transport member 80 in the transport direction may also be formed with a spiral blade that is wound in the opposite direction to the blades 83 and 84.

ここで、大径部９２Ａに形成された各羽根９６、９７の外径Ｄ１は、図４に示されるように、羽根９３、９４の外径Ｄ２と同じとされている。また、各羽根９６、９７の螺旋ピッチＰ１は、各羽根９３、９４の螺旋ピッチＰ２と同じとされている。 Here, the outer diameters D1 of the blades 96 and 97 formed on the large diameter portion 92A are the same as the outer diameters D2 of the blades 93 and 94, as shown in FIG. Further, the spiral pitch P1 of the blades 96 and 97 is the same as the spiral pitch P2 of the blades 93 and 94.

直上流部分９２Ｂに形成された羽根９１の外径Ｄ３は、各羽根９６、９７の外径Ｄ１よりも小さくされている。なお、外径Ｄ３は、羽根９６、９７を含まない大径部９２Ａ自体の外径よりも大きくされている。羽根９１の螺旋ピッチＰ３は、各羽根９６、９７の螺旋ピッチＰ１よりも小さくされている。螺旋ピッチＰ３は、一例として、螺旋ピッチＰ１の略半分程度とされている。 The outer diameter D3 of the blade 91 formed in the immediately upstream portion 92B is smaller than the outer diameter D1 of each of the blades 96 and 97. The outer diameter D3 is larger than the outer diameter of the large diameter portion 92A itself, which does not include the blades 96 and 97. The spiral pitch P3 of the blades 91 is smaller than the spiral pitch P1 of the blades 96 and 97, respectively. As an example, the spiral pitch P3 is about half of the spiral pitch P1.

なお、螺旋ピッチとは、羽根における軸部９２の周方向の３６０度（一周）当たりの軸方向長さをいう。 The spiral pitch refers to the axial length per 360 degrees (one circumference) of the shaft portion 92 in the blade in the circumferential direction.

また、大径部９２Ａには、二条の羽根９６、９７が形成されているのに対して、直上流部分９２Ｂには、一条の羽根９１が形成されている。すなわち、羽根９１は、条数が羽根９６、９７の条数よりも少なくされている。 Further, the large diameter portion 92A is formed with two blades 96 and 97, whereas the immediately upstream portion 92B is formed with a single blade 91. That is, the number of the blades 91 is smaller than the number of the blades 96 and 97.

上流部分９２Ｃに形成された羽根９８、９９の外径Ｄ４は、羽根９１の外径Ｄ３よりも大きくされている。具体的には、羽根９８、９９の外径Ｄ４は、羽根９６、９７の外径Ｄ１と同じとされている。なお、羽根９８、９９の外径Ｄ４は、羽根９１の外径Ｄ３よりも大きければ、羽根９６、９７の外径Ｄ１と異なっていてもよい。 The outer diameters D4 of the blades 98 and 99 formed on the upstream portion 92C are larger than the outer diameter D3 of the blades 91. Specifically, the outer diameter D4 of the blades 98 and 99 is the same as the outer diameter D1 of the blades 96 and 97. The outer diameter D4 of the blades 98 and 99 may be different from the outer diameter D1 of the blades 96 and 97 as long as it is larger than the outer diameter D3 of the blade 91.

上流部分９２Ｃに形成された羽根９８、９９の螺旋ピッチＰ４は、羽根９１の螺旋ピッチＰ３よりも大きくされている。具体的には、羽根９８、９９の螺旋ピッチＰ４は、羽根９６、９７の螺旋ピッチＰ１と同じとされている。なお、羽根９８、９９の螺旋ピッチＰ４は、羽根９１の螺旋ピッチＰ３よりも大きければ、羽根９６、９７の螺旋ピッチＰ１と異なっていてもよい。 The spiral pitch P4 of the blades 98 and 99 formed on the upstream portion 92C is made larger than the spiral pitch P3 of the blade 91. Specifically, the spiral pitch P4 of the blades 98 and 99 is the same as the spiral pitch P1 of the blades 96 and 97. The spiral pitch P4 of the blades 98 and 99 may be different from the spiral pitch P1 of the blades 96 and 97 as long as it is larger than the spiral pitch P3 of the blade 91.

また、直上流部分９２Ｂには、一条の羽根９１が形成されているのに対して、上流部分９２Ｃには、二条の羽根９８、９９が形成されている。すなわち、羽根９８、９９は、条数が、羽根９１の条数よりも多くされている。 Further, the straight upstream portion 92B is formed with a single blade 91, whereas the upstream portion 92C is formed with two blades 98 and 99. That is, the number of rows of the blades 98 and 99 is larger than the number of rows of the blades 91.

なお、本実施形態では、制御部２０（図１参照）が駆動源６１の駆動を制御することで、軸部８２及び軸部９２の回転数（単位時間当たりに回転する数）が制御される。本実施形態では、制御部２０は、少なくとも、予め定められた回転数で軸部８２及び軸部９２を回転させる第一モードと、第一モードの場合よりも多い回転数で軸部８２及び軸部９２を回転させる第二モードと、を有している。 In the present embodiment, the control unit 20 (see FIG. 1) controls the drive of the drive source 61 to control the rotation speed (the number of rotations per unit time) of the shaft unit 82 and the shaft unit 92. .. In the present embodiment, the control unit 20 has at least the first mode in which the shaft portion 82 and the shaft portion 92 are rotated at a predetermined rotation speed, and the shaft portion 82 and the shaft at a higher rotation speed than in the case of the first mode. It has a second mode for rotating the unit 92.

第一モードは、例えば、予め定められた基準となる動作速度（プロセススピード）で、画像形成動作を実行する場合に用いられる。 The first mode is used, for example, when the image forming operation is executed at a predetermined reference operating speed (process speed).

一方、第二モードは、例えば、予め定められた基準となる動作速度（プロセススピード）よりも速い動作速度で画像形成動作を実行する場合に用いられる。当該速い動作速度で画像形成動作を実行する場合とは、例えば、画像を定着する際に付与される加熱量が相対的に少ない薄紙に画像形成動作を実行する場合が挙げられる。 On the other hand, the second mode is used, for example, when the image forming operation is executed at an operation speed faster than a predetermined reference operation speed (process speed). The case where the image forming operation is executed at the high operating speed includes, for example, the case where the image forming operation is executed on a thin paper in which the amount of heat applied when fixing the image is relatively small.

なお、第一モードは、予め定められた基準となる動作速度（プロセススピード）よりも遅い動作速度で画像形成動作を実行する場合に用いてもよい。当該遅い動作速度で画像形成動作を実行する場合とは、例えば、画像を定着する際に付与される加熱量が相対的に多い厚紙に画像形成動作を実行する場合が挙げられる。この場合では、第二モードは、予め定められた基準となる動作速度（プロセススピード）で、画像形成動作を実行する場合に用いてもよい。 The first mode may be used when the image forming operation is executed at an operation speed slower than a predetermined reference operation speed (process speed). The case where the image forming operation is executed at the slow operation speed includes, for example, the case where the image forming operation is executed on a thick paper in which the amount of heat applied when fixing the image is relatively large. In this case, the second mode may be used when the image forming operation is executed at a predetermined reference operating speed (process speed).

（本実施形態に係る作用）
次に、本実施形態に係る作用を説明する。 (Action according to this embodiment)
Next, the operation according to this embodiment will be described.

例えば、第一モードにて軸部９２を回転させると、軸部９２の上流部分９２Ｃでは、羽根９８、９９が、現像剤Ｇを直上流部分９２Ｂへ搬送する。軸部９２の直上流部分９２Ｂでは、羽根９１が、大径部９２Ａへ向かって搬送する。大径部９２Ａの搬送方向上流端に搬送された現像剤Ｇは、一部が大径部９２Ａの上流端面９２Ｅによって移動が制限される。大径部９２Ａの上流端面９２Ｅで制限されずに、大径部９２Ａへ移動した現像剤Ｇは、羽根９６、９７、９３、９４によって、軸方向の一方（＋Ｘ方向）へ搬送される。 For example, when the shaft portion 92 is rotated in the first mode, the blades 98 and 99 convey the developer G to the immediately upstream portion 92B in the upstream portion 92C of the shaft portion 92. In the portion 92B immediately upstream of the shaft portion 92, the blade 91 conveys toward the large diameter portion 92A. The movement of the developer G transported to the upstream end of the large diameter portion 92A in the transport direction is partially restricted by the upstream end surface 92E of the large diameter portion 92A. The developer G that has moved to the large diameter portion 92A without being restricted by the upstream end surface 92E of the large diameter portion 92A is conveyed in one of the axial directions (+ X direction) by the blades 96, 97, 93, 94.

このように、現像剤Ｇの一部の移動が、大径部９２Ａの上流端面９２Ｅによって制限されることで、大径部９２Ａの搬送方向下流側へ搬送される現像剤Ｇの単位回転数当りの搬送量の変動が抑制される。 In this way, the movement of a part of the developer G is restricted by the upstream end surface 92E of the large diameter portion 92A, so that the movement of a part of the developer G is restricted per unit rotation speed of the developer G transported to the downstream side in the transport direction of the large diameter portion 92A. Fluctuations in the amount of transport are suppressed.

ここで、直上流部分９２Ｂに形成された羽根９１の外径Ｄ３が、各羽根９６、９７の外径Ｄ１と同じである第一比較例では、第一モードよりも回転数が多い第二モードにて軸部９２を回転させると、大径部９２Ａへ搬送される現像剤Ｇの量が多くなるため、直上流部分９２Ｂで現像剤Ｇが滞留しにくい。すなわち、直上流部分９２Ｂでの現像剤Ｇの嵩が低下する。これにより、直上流部分９２Ｂの現像剤Ｇが大径部９２Ａの上流端面９２Ｅによって制限される現像剤Ｇの量が変動しやすくなる。すなわち、直上流部分９２Ｂで滞留した現像剤Ｇの量のうち、大径部９２Ａの上流端面９２Ｅによって移動が制限される現像剤Ｇの量の割合が変動しやすくなる。これにより、大径部９２Ａの搬送方向下流側へ搬送される現像剤Ｇの単位回転数当りの搬送量が変動しやすくなる。特に、キャリアに対するトナーの濃度が高く、現像剤Ｇの量が多い場合では、大径部９２Ａの搬送方向下流側へ搬送される単位回転数当りの搬送量が変動しやすい。 Here, in the first comparative example in which the outer diameter D3 of the blade 91 formed in the immediately upstream portion 92B is the same as the outer diameter D1 of each of the blades 96 and 97, the second mode has a higher rotation speed than the first mode. When the shaft portion 92 is rotated, the amount of the developer G transported to the large diameter portion 92A increases, so that the developer G is unlikely to stay in the immediately upstream portion 92B. That is, the bulk of the developer G in the immediately upstream portion 92B is reduced. As a result, the amount of the developer G in which the developer G in the immediately upstream portion 92B is limited by the upstream end surface 92E in the large diameter portion 92A tends to fluctuate. That is, the ratio of the amount of the developer G whose movement is restricted by the upstream end surface 92E of the large diameter portion 92A to the amount of the developer G retained in the immediately upstream portion 92B tends to fluctuate. As a result, the amount of the developer G transported to the downstream side in the transport direction of the large diameter portion 92A is likely to fluctuate per unit rotation speed. In particular, when the toner concentration with respect to the carrier is high and the amount of the developer G is large, the amount of the large diameter portion 92A transported to the downstream side in the transport direction tends to fluctuate per unit rotation speed.

これに対して、本実施形態では、直上流部分９２Ｂに形成された羽根９１の外径Ｄ３は、各羽根９６、９７の外径Ｄ１よりも小さくされている。これにより、羽根９１において、軸部９２から径方向外側へ張り出した部分の面積が第一比較例に比べて小さくなるため、第一モードよりも回転数が多い第二モードにて軸部９２を回転させても、大径部９２Ａへ搬送される単位回転数当りの搬送量が多くなりにくい。 On the other hand, in the present embodiment, the outer diameter D3 of the blade 91 formed in the immediately upstream portion 92B is smaller than the outer diameter D1 of each of the blades 96 and 97. As a result, in the blade 91, the area of the portion protruding outward in the radial direction from the shaft portion 92 becomes smaller than that in the first comparative example. Even if it is rotated, the amount of transportation per unit rotation speed transferred to the large diameter portion 92A is unlikely to increase.

このため、第一比較例に比べて、直上流部分９２Ｂで現像剤Ｇが滞留しやすく、直上流部分９２Ｂでの現像剤Ｇの嵩が高い状態が維持される。すなわち、嵩の高さが、第一モードにおける嵩の高さと同等の高さになる。 Therefore, as compared with the first comparative example, the developer G tends to stay in the direct upstream portion 92B, and the bulk of the developer G in the direct upstream portion 92B is maintained. That is, the height of the bulk becomes the same as the height of the bulk in the first mode.

特に、羽根９１の外径Ｄ３を各羽根９６、９７の外径Ｄ１よりも小さくすることで、羽根９１における大径部９２Ａよりも径方向外側へ張り出した部分の面積が小さくなるため、大径部９２Ａと筐体６２との間の空間へ現像剤Ｇを押し込む力が低下する。このため、直上流部分９２Ｂで現像剤Ｇが滞留しやすく、直上流部分９２Ｂでの現像剤Ｇの嵩が高い状態が効果的に維持される。 In particular, by making the outer diameter D3 of the blade 91 smaller than the outer diameter D1 of each of the blades 96 and 97, the area of the portion of the blade 91 that projects outward in the radial direction is smaller than that of the large diameter portion 92A. The force for pushing the developer G into the space between the portion 92A and the housing 62 is reduced. Therefore, the developer G tends to stay in the direct upstream portion 92B, and the bulky state of the developer G in the direct upstream portion 92B is effectively maintained.

これにより、第一比較例に比べて、直上流部分９２Ｂの現像剤Ｇが大径部９２Ａの上流端面９２Ｅによって制限される現像剤Ｇの量が変動しにくい。すなわち、第一比較例に比べて、直上流部分９２Ｂに滞留した現像剤Ｇの量のうち、大径部９２Ａの上流端面９２Ｅによって制限される現像剤Ｇの量の割合が変動しにくい。これにより、軸部９２の回転数が変化しても、第一比較例に比べて、大径部９２Ａの搬送方向下流側へ搬送される現像剤Ｇの単位回転数当りの搬送量の変動が抑制される。 As a result, the amount of the developer G in which the developer G in the direct upstream portion 92B is limited by the upstream end surface 92E in the large diameter portion 92A is less likely to fluctuate as compared with the first comparative example. That is, as compared with the first comparative example, the ratio of the amount of the developer G limited by the upstream end surface 92E of the large diameter portion 92A to the amount of the developer G retained in the immediately upstream portion 92B is less likely to fluctuate. As a result, even if the rotation speed of the shaft portion 92 changes, the transfer amount of the developer G transported to the downstream side in the transport direction of the large diameter portion 92A per unit rotation speed changes as compared with the first comparative example. It is suppressed.

また、本実施形態では、羽根９１の螺旋ピッチＰ３は、各羽根９６、９７の螺旋ピッチＰ１よりも小さくされている。これにより、羽根９１の螺旋ピッチＰ３が各羽根９７の螺旋ピッチＰ１と同じである第二比較例に比べ、軸部９２の単位回転数当たりに現像剤Ｇを搬送する軸方向長さが短くなる。このため、第二比較例に比べ、第一モードよりも回転数が多い第二モードにて軸部９２を回転させても、大径部９２Ａへ搬送される現像剤Ｇの量が多くなりにくい。 Further, in the present embodiment, the spiral pitch P3 of the blades 91 is made smaller than the spiral pitch P1 of the blades 96 and 97, respectively. As a result, the axial length for transporting the developer G per unit rotation speed of the shaft portion 92 becomes shorter than that in the second comparative example in which the spiral pitch P3 of the blades 91 is the same as the spiral pitch P1 of each blade 97. .. Therefore, as compared with the second comparative example, even if the shaft portion 92 is rotated in the second mode, which has a higher rotation speed than the first mode, the amount of the developer G conveyed to the large diameter portion 92A is unlikely to increase. ..

したがって、第二比較例に比べて、直上流部分９２Ｂで現像剤Ｇが滞留しやすく、直上流部分９２Ｂでの現像剤Ｇの嵩が高い状態が維持される。すなわち、嵩の高さが、第一モードにおける嵩の高さと同等の高さになる。 Therefore, as compared with the second comparative example, the developer G is more likely to stay in the direct upstream portion 92B, and the bulkiness of the developer G in the direct upstream portion 92B is maintained. That is, the height of the bulk becomes the same as the height of the bulk in the first mode.

これにより、第二比較例に比べて、直上流部分９２Ｂの現像剤Ｇが大径部９２Ａの上流端面９２Ｅによって制限される現像剤Ｇの量が変動しにくい。すなわち、第二比較例に比べて、直上流部分９２Ｂに滞留した現像剤Ｇの量のうち、大径部９２Ａの上流端面９２Ｅによって制限される現像剤Ｇの量の割合が変動しにくい。これにより、軸部９２の回転数が変化しても、第二比較例に比べて、大径部９２Ａの搬送方向下流側へ搬送される現像剤Ｇの単位回転数当りの搬送量の変動が抑制される。 As a result, the amount of the developer G in which the developer G in the direct upstream portion 92B is limited by the upstream end surface 92E in the large diameter portion 92A is less likely to fluctuate as compared with the second comparative example. That is, as compared with the second comparative example, the ratio of the amount of the developer G limited by the upstream end surface 92E of the large diameter portion 92A to the amount of the developer G retained in the immediately upstream portion 92B is less likely to fluctuate. As a result, even if the rotation speed of the shaft portion 92 changes, the transfer amount of the developer G transported to the downstream side in the transport direction of the large diameter portion 92A fluctuates per unit rotation speed as compared with the second comparative example. It is suppressed.

また、本実施形態では、羽根９１の条数が羽根９６、９７の条数よりも少なくされている。これにより、羽根９１の条数が羽根９６、９７の条数と同じである第三比較例に比べ、現像剤Ｇを搬送方向下流側へ押す羽根の全体の面積が小さくなる。このため、第三比較例に比べ、第一モードよりも回転数が多い第二モードにて軸部９２を回転させても、大径部９２Ａへ搬送される現像剤Ｇの量が多くなりにくい。 Further, in the present embodiment, the number of blades 91 is smaller than the number of blades 96 and 97. As a result, the total area of the blades that pushes the developer G downstream in the transport direction becomes smaller than that of the third comparative example in which the number of blades 91 is the same as the number of blades 96 and 97. Therefore, as compared with the third comparative example, even if the shaft portion 92 is rotated in the second mode, which has a higher rotation speed than the first mode, the amount of the developer G conveyed to the large diameter portion 92A is unlikely to increase. ..

したがって、第三比較例に比べて、直上流部分９２Ｂで現像剤Ｇが滞留しやすく、直上流部分９２Ｂでの現像剤Ｇの嵩が高い状態が維持される。すなわち、嵩の高さが、第一モードにおける嵩の高さと同等の高さになる。 Therefore, as compared with the third comparative example, the developer G tends to stay in the immediately upstream portion 92B, and the bulkiness of the developer G in the direct upstream portion 92B is maintained. That is, the height of the bulk becomes the same as the height of the bulk in the first mode.

これにより、第三比較例に比べて、直上流部分９２Ｂの現像剤Ｇが大径部９２Ａの上流端面９２Ｅによって制限される現像剤Ｇの量が変動しにくい。すなわち、第三比較例に比べて、直上流部分９２Ｂに滞留した現像剤Ｇの量のうち、大径部９２Ａの上流端面９２Ｅによって制限される現像剤Ｇの量の割合が変動しにくい。これにより、軸部９２の回転数が変化しても、第三比較例に比べて、大径部９２Ａの搬送方向下流側へ搬送される現像剤Ｇの単位回転数当りの搬送量の変動が抑制される。 As a result, the amount of the developer G in which the developer G in the direct upstream portion 92B is limited by the upstream end surface 92E in the large diameter portion 92A is less likely to fluctuate as compared with the third comparative example. That is, as compared with the third comparative example, the ratio of the amount of the developer G limited by the upstream end surface 92E of the large diameter portion 92A to the amount of the developer G retained in the immediately upstream portion 92B is less likely to fluctuate. As a result, even if the rotation speed of the shaft portion 92 changes, the transfer amount per unit rotation speed of the developer G transported to the downstream side in the transport direction of the large diameter portion 92A changes as compared with the third comparative example. It is suppressed.

また、本実施形態では、上流部分９２Ｃに形成された羽根９８、９９の外径Ｄ４は、羽根９１の外径Ｄ３よりも大きくされている。これにより、羽根９８、９９の外径Ｄ４が、羽根９１の外径Ｄ３と同じである第四比較例に比べ、上流部分９２Ｃから直上流部分９２Ｂへ搬送される現像剤Ｇの量が多くなるため、直上流部分９２Ｂで現像剤Ｇが滞留しやすく、直上流部分９２Ｂでの現像剤Ｇの嵩が高い状態が維持される。すなわち、嵩の高さが、第一モードにおける嵩の高さと同等の高さになる。 Further, in the present embodiment, the outer diameters D4 of the blades 98 and 99 formed on the upstream portion 92C are larger than the outer diameter D3 of the blades 91. As a result, the amount of the developer G transported from the upstream portion 92C to the immediately upstream portion 92B increases as compared with the fourth comparative example in which the outer diameters D4 of the blades 98 and 99 are the same as the outer diameter D3 of the blades 91. Therefore, the developer G tends to stay in the direct upstream portion 92B, and the bulkiness of the developer G in the direct upstream portion 92B is maintained. That is, the height of the bulk becomes the same as the height of the bulk in the first mode.

これにより、第四比較例に比べて、直上流部分９２Ｂの現像剤Ｇが大径部９２Ａの上流端面９２Ｅによって制限される現像剤Ｇの量が変動しにくい。すなわち、第四比較例に比べて、直上流部分９２Ｂに滞留した現像剤Ｇの量のうち、大径部９２Ａの上流端面９２Ｅによって制限される現像剤Ｇの量の割合が変動しにくい。これにより、軸部９２の回転数が変化しても、第四比較例に比べて、大径部９２Ａの搬送方向下流側へ搬送される現像剤Ｇの単位回転数当りの搬送量の変動が抑制される。 As a result, the amount of the developer G in which the developer G in the immediately upstream portion 92B is limited by the upstream end surface 92E in the large diameter portion 92A is less likely to fluctuate as compared with the fourth comparative example. That is, as compared with the fourth comparative example, the ratio of the amount of the developer G limited by the upstream end surface 92E of the large diameter portion 92A to the amount of the developer G retained in the immediately upstream portion 92B is less likely to fluctuate. As a result, even if the rotation speed of the shaft portion 92 changes, the transfer amount of the developer G transported to the downstream side in the transport direction of the large diameter portion 92A fluctuates per unit rotation speed as compared with the fourth comparative example. It is suppressed.

また、本実施形態では、上流部分９２Ｃに形成された羽根９８、９９の螺旋ピッチＰ４は、羽根９１の螺旋ピッチＰ３よりも大きくされている。これにより、羽根９８、９９の螺旋ピッチＰ４が、羽根９１の螺旋ピッチＰ３と同じである第五比較例に比べ、軸部９２の単位回転数当たりに現像剤Ｇを搬送する軸方向長さが長くなる。 Further, in the present embodiment, the spiral pitch P4 of the blades 98 and 99 formed on the upstream portion 92C is made larger than the spiral pitch P3 of the blade 91. As a result, the axial length for transporting the developer G per unit rotation speed of the shaft portion 92 is increased as compared with the fifth comparative example in which the spiral pitch P4 of the blades 98 and 99 is the same as the spiral pitch P3 of the blade 91. become longer.

したがって、上流部分９２Ｃから直上流部分９２Ｂへ搬送される現像剤Ｇの量が多くなるため、直上流部分９２Ｂで現像剤Ｇが滞留しやすく、直上流部分９２Ｂでの現像剤Ｇの嵩が高い状態が維持される。すなわち、嵩の高さが、第一モードにおける嵩の高さと同等の高さになる。 Therefore, since the amount of the developer G transported from the upstream portion 92C to the direct upstream portion 92B increases, the developer G tends to stay in the direct upstream portion 92B, and the bulk of the developer G in the direct upstream portion 92B is high. The state is maintained. That is, the height of the bulk becomes the same as the height of the bulk in the first mode.

これにより、第五比較例に比べて、直上流部分９２Ｂの現像剤Ｇが大径部９２Ａの上流端面９２Ｅによって制限される現像剤Ｇの量が変動しにくい。すなわち、第五比較例に比べて、直上流部分９２Ｂに滞留した現像剤Ｇの量のうち、大径部９２Ａの上流端面９２Ｅによって制限される現像剤Ｇの量の割合が変動しにくい。これにより、軸部９２の回転数が変化しても、第五比較例に比べて、大径部９２Ａの搬送方向下流側へ搬送される現像剤Ｇの単位回転数当りの搬送量の変動が抑制される。 As a result, the amount of the developer G in which the developer G in the immediately upstream portion 92B is limited by the upstream end surface 92E in the large diameter portion 92A is less likely to fluctuate as compared with the fifth comparative example. That is, as compared with the fifth comparative example, the ratio of the amount of the developer G limited by the upstream end surface 92E of the large diameter portion 92A to the amount of the developer G retained in the immediately upstream portion 92B is less likely to fluctuate. As a result, even if the rotation speed of the shaft portion 92 changes, the transfer amount of the developer G transported to the downstream side in the transport direction of the large diameter portion 92A fluctuates per unit rotation speed as compared with the fifth comparative example. It is suppressed.

また、本実施形態では、羽根９８、９９の条数が、羽根９１の条数よりも多くされている。これにより、羽根９８、９９の条数が、羽根９１の条数とで同じである第六比較例に比べ、現像剤Ｇを搬送方向下流側へ押す羽根の全体の面積が大きくなる。このため、上流部分９２Ｃから直上流部分９２Ｂへ搬送される現像剤Ｇの量が多くなるため、直上流部分９２Ｂで現像剤Ｇが滞留しやすく、直上流部分９２Ｂでの現像剤Ｇの嵩が高い状態が維持される。すなわち、嵩の高さが、第一モードにおける嵩の高さと同等の高さになる。 Further, in the present embodiment, the number of blades 98 and 99 is larger than the number of blades 91. As a result, the total area of the blades that pushes the developer G downstream in the transport direction becomes larger than that of the sixth comparative example in which the number of blades 98 and 99 is the same as the number of blades 91. Therefore, since the amount of the developer G transported from the upstream portion 92C to the direct upstream portion 92B increases, the developer G tends to stay in the direct upstream portion 92B, and the bulk of the developer G in the direct upstream portion 92B increases. High condition is maintained. That is, the height of the bulk becomes the same as the height of the bulk in the first mode.

これにより、第六比較例に比べて、直上流部分９２Ｂの現像剤Ｇが大径部９２Ａの上流端面９２Ｅによって制限される現像剤Ｇの量が変動しにくい。すなわち、第六比較例に比べて、直上流部分９２Ｂに滞留した現像剤Ｇの量のうち、大径部９２Ａの上流端面９２Ｅによって制限される現像剤Ｇの量の割合が変動しにくい。これにより、軸部９２の回転数が変化しても、第六比較例に比べて、大径部９２Ａの搬送方向下流側へ搬送される現像剤Ｇの単位回転数当りの搬送量の変動が抑制される。 As a result, the amount of the developer G in which the developer G in the immediately upstream portion 92B is limited by the upstream end surface 92E in the large diameter portion 92A is less likely to fluctuate as compared with the sixth comparative example. That is, as compared with the sixth comparative example, the ratio of the amount of the developer G limited by the upstream end surface 92E of the large diameter portion 92A to the amount of the developer G retained in the immediately upstream portion 92B is less likely to fluctuate. As a result, even if the rotation speed of the shaft portion 92 changes, the transfer amount of the developer G transported to the downstream side in the transport direction of the large diameter portion 92A fluctuates per unit rotation speed as compared with the sixth comparative example. It is suppressed.

このように、本実施形態では、大径部９２Ａの搬送方向下流側へ搬送される現像剤Ｇの単位回転数当りの搬送量の変動が抑制されるので、現像剤Ｇの単位回転数当りの搬送量の変動に起因する現像不良が抑制される。この現像不良に起因する画像不良が抑制される。 As described above, in the present embodiment, the fluctuation of the transport amount per unit rotation speed of the developer G transported to the downstream side in the transport direction of the large diameter portion 92A is suppressed, so that the per unit rotation speed of the developer G is suppressed. Development defects caused by fluctuations in the transport amount are suppressed. Image defects caused by this development defect are suppressed.

（第一変形例）
上記の実施形態では、搬送路６９は、＋Ｙ方向に沿った路幅がＸ方向に一定とされていたが、これに限られない。筐体６２は、図５に示されるように、筐体６２を構成する側壁６２Ｃ及び仕切壁６７の内壁において、大径部９２Ａにおいて内側に張り出す張出部１１０を備えていてもよい。これにより、大径部９２Ａにおける供給路６８の路幅が、他の部位における路幅よりも狭くなる。張出部１１０は、大径部９２Ａの外周面に沿って、軸方向視にて円弧状に形成されている。具体的には、張出部１１０は、例えば、大径部９２Ａの下半分の外周面に沿って略半円状とされる。 (First modification)
In the above embodiment, the width of the transport path 69 along the + Y direction is constant in the X direction, but the present invention is not limited to this. As shown in FIG. 5, the housing 62 may include an overhanging portion 110 that projects inward in the large diameter portion 92A on the inner wall of the side wall 62C and the partition wall 67 that constitute the housing 62. As a result, the road width of the supply path 68 in the large diameter portion 92A becomes narrower than the road width in other portions. The overhanging portion 110 is formed in an arc shape in the axial direction along the outer peripheral surface of the large diameter portion 92A. Specifically, the overhanging portion 110 has a substantially semicircular shape along the outer peripheral surface of the lower half of the large diameter portion 92A, for example.

張出部１１０の搬送方向の上流端及び下流端のそれぞれに、−Ｘ方向側を向く上流端面１１２と、＋Ｘ方向側を向く下流端面１１４が形成されている。この張出部１１０の上流端面１１２は、大径部９２Ａの上流端面９２Ｅの上流側に配置されている。張出部１１０の下流端面１１４は、大径部９２Ａの下流端面９２Ｆの下流側に配置されている。なお、張出部１１０は、大径部９２Ａにおいて、少なくとも大径部９２Ａの羽根９６、９７の１ピッチ分以上の軸方向長さ（Ｘ方向長さ）を有していることが好ましい。 An upstream end surface 112 facing the −X direction side and a downstream end surface 114 facing the + X direction side are formed at each of the upstream end and the downstream end of the overhanging portion 110 in the transport direction. The upstream end surface 112 of the overhanging portion 110 is arranged on the upstream side of the upstream end surface 92E of the large diameter portion 92A. The downstream end face 114 of the overhanging portion 110 is arranged on the downstream side of the downstream end face 92F of the large diameter portion 92A. The overhanging portion 110 preferably has an axial length (length in the X direction) of at least one pitch of the blades 96 and 97 of the large diameter portion 92A in the large diameter portion 92A.

第一変形例では、軸部９２の直上流部分９２Ｂでは、羽根９１が、大径部９２Ａへ向かって搬送する。張出部１１０の搬送方向上流端に搬送された現像剤Ｇは、張出部１１０の上流端面１１２によって移動が制限される。このように、現像剤Ｇの移動が、大径部９２Ａの上流端面９２Ｅに加えて、張出部１１０の上流端面１１２によっても制限されることで、大径部９２Ａの搬送方向下流側へ搬送される現像剤Ｇの単位回転数当りの搬送量の変動が効果的に抑制される。 In the first modification, in the portion 92B immediately upstream of the shaft portion 92, the blade 91 conveys toward the large diameter portion 92A. The movement of the developer G transported to the upstream end in the transport direction of the overhanging portion 110 is restricted by the upstream end surface 112 of the overhanging portion 110. In this way, the movement of the developer G is restricted not only by the upstream end surface 92E of the large diameter portion 92A but also by the upstream end surface 112 of the overhanging portion 110, so that the developer G is transported to the downstream side in the transport direction of the large diameter portion 92A. Fluctuations in the amount of the developer G transported per unit rotation speed are effectively suppressed.

これにより、筐体６２の内壁が平断面視で直線状である構成（搬送路６９の路幅がＸ方向に一定である構成）に比べ、軸部９２の回転数が変化しても、大径部９２Ａの搬送方向下流側へ搬送される現像剤Ｇの単位回転数当りの搬送量の変動が抑制される。 As a result, even if the rotation speed of the shaft portion 92 changes, it is larger than the configuration in which the inner wall of the housing 62 is linear in a plan view (the configuration in which the width of the transport path 69 is constant in the X direction). Fluctuations in the amount of the developer G transported to the downstream side in the transport direction of the diameter portion 92A per unit rotation speed are suppressed.

さらに、第一変形例では、張出部１１０の上流端面１１２は、大径部９２Ａの上流端面９２Ｅの上流側に配置されている。ここで、直上流部分９２Ｂでは、羽根９１の下流端（大径部９２Ａの上流端面９２Ｅ）ではなく、羽根９１の下流端から羽根９１の半ピッチから１ピッチ程度上流側の位置で、現像剤Ｇが最も滞留した状態となりやすい。したがって、直上流部分９２Ｂにおける現像剤Ｇの嵩のピークが、直上流部分９２Ｂの下流端よりも上流側の位置で生じやすい。 Further, in the first modification, the upstream end surface 112 of the overhanging portion 110 is arranged on the upstream side of the upstream end surface 92E of the large diameter portion 92A. Here, in the direct upstream portion 92B, the developer is not at the downstream end of the blade 91 (upstream end surface 92E of the large diameter portion 92A), but at a position on the upstream side from the downstream end of the blade 91 by about one pitch from the half pitch of the blade 91. G is most likely to stay in the state. Therefore, the peak of the bulk of the developer G in the immediately upstream portion 92B is likely to occur at a position on the upstream side of the downstream end of the immediately upstream portion 92B.

張出部１１０の上流端面１１２は、大径部９２Ａの上流端面９２Ｅの上流側に配置されているので、現像剤Ｇの嵩のピークにおいて、張出部１１０の上流端面１１２で現像剤Ｇの移動が制限される。これにより、大径部９２Ａの搬送方向下流側へ搬送される現像剤Ｇの単位回転数当りの搬送量の変動が効果的に抑制される。 Since the upstream end face 112 of the overhanging portion 110 is arranged on the upstream side of the upstream end face 92E of the large diameter portion 92A, at the peak of the bulk of the developing agent G, the upstream end face 112 of the overhanging portion 110 of the developing agent G Movement is restricted. As a result, fluctuations in the amount of the developer G transported to the downstream side in the transport direction of the large diameter portion 92A per unit rotation speed are effectively suppressed.

（他の変形例）
本実施形態では、羽根９１の螺旋ピッチＰ３は、各羽根９６、９７の螺旋ピッチＰ１よりも小さくされていたが、これに限られない。例えば、羽根９１の螺旋ピッチＰ３は、各羽根９６、９７の螺旋ピッチＰ１と同じであってもよい。 (Other variants)
In the present embodiment, the spiral pitch P3 of the blades 91 is smaller than the spiral pitch P1 of the blades 96 and 97, but the present invention is not limited to this. For example, the spiral pitch P3 of the blade 91 may be the same as the spiral pitch P1 of the blades 96 and 97, respectively.

また、本実施形態では、羽根９１の条数は、羽根９６、９７の条数よりも少なくされていたが、これに限られない。例えば、羽根９１の条数は、羽根９６、９７の条数と同じであってもよい。 Further, in the present embodiment, the number of the blades 91 is smaller than the number of the blades 96 and 97, but the number is not limited to this. For example, the number of blades 91 may be the same as the number of blades 96 and 97.

また、本実施形態では、羽根９８、９９の螺旋ピッチＰ４は、羽根９１の螺旋ピッチＰ３よりも大きくされていたが、これに限られない。例えば、羽根９８、９９の螺旋ピッチＰ４は、羽根９１の螺旋ピッチＰ３と同じであってもよい。 Further, in the present embodiment, the spiral pitch P4 of the blades 98 and 99 is made larger than the spiral pitch P3 of the blade 91, but the present invention is not limited to this. For example, the spiral pitch P4 of the blades 98 and 99 may be the same as the spiral pitch P3 of the blade 91.

また、本実施形態では、羽根９８、９９の条数は、羽根９１の条数よりも多くされていたが、これに限られない。例えば、羽根９８、９９の条数は、羽根９１の条数と同じであってもよい。 Further, in the present embodiment, the number of the blades 98 and 99 is larger than the number of the blades 91, but the number is not limited to this. For example, the number of blades 98 and 99 may be the same as the number of blades 91.

本実施形態では、粉体として、現像剤Ｇを用いたがこれに限られない。粉体としては、粉状のものであればよい。 In the present embodiment, the developer G is used as the powder, but the present invention is not limited to this. The powder may be powdery.

本発明は、上記の実施形態に限るものではなく、その主旨を逸脱しない範囲内において種々の変形、変更、改良が可能である。 The present invention is not limited to the above-described embodiment, and various modifications, changes, and improvements can be made within a range that does not deviate from the gist thereof.

１０画像形成装置
２６転写ロール（転写部の一例）
３２感光体ドラム（保持体の一例）
６０現像装置（搬送装置の一例）
６２筐体
９１羽根（第二羽根の一例）
９６、９７羽根（第一羽根の一例）
９２軸部
９２Ａ大径部
９２Ｂ直上流部分
９２Ｃ上流部分
９２Ｅ上流端面
９８、９８羽根（第三羽根の一例）
１１０張出部
１１２上流端面
Ｇ現像剤（粉体の一例） 10 Image forming device 26 Transfer roll (example of transfer unit)
32 Photoreceptor drum (example of holder)
60 Developing equipment (an example of transport equipment)
62 Housing 91 blades (an example of the second blade)
96, 97 blades (an example of the first blade)
92 Shaft part 92A Large diameter part 92B Direct upstream part 92C Upstream part 92E Upstream end face 98, 98 blades (example of third blade)
110 Overhanging part 112 Upstream end face G developer (example of powder)

Claims

A housing containing powder and
A shaft portion arranged inside the housing and having a large diameter portion having a large diameter in a part in the axial direction, and a shaft portion having a large diameter portion.
A first blade formed spirally on the outer peripheral surface of the large-diameter portion and transporting the powder in one direction in the axial direction by rotation of the shaft portion.
The powder is spirally formed on the outer peripheral surface of the upstream portion of the shaft portion with respect to the large diameter portion, and the powder is conveyed to the one by the rotation of the shaft portion, and the outer diameter is larger than the outer diameter of the first blade. With the second blade made smaller,
With
The second blade is a transport device in which the number of rows is smaller than the number of rows of the first blade.

A housing containing powder and
A shaft portion arranged inside the housing and having a large diameter portion having a large diameter in a part in the axial direction, and a shaft portion having a large diameter portion.
A first blade formed spirally on the outer peripheral surface of the large-diameter portion and transporting the powder in one direction in the axial direction by rotation of the shaft portion.
The powder is spirally formed on the outer peripheral surface of the upstream portion of the shaft portion with respect to the large diameter portion, and the powder is conveyed to the one by the rotation of the shaft portion, and the outer diameter is larger than the outer diameter of the first blade. With the second blade made smaller,
With
The housing has an overhanging portion whose inner wall projects inward in the large diameter portion.
The upstream end face of the overhanging portion is arranged on the upstream side of the upstream end face of the large diameter portion.
Transport device.

The spiral pitch of the second blade is smaller than the spiral pitch of the first blade.
The transport device according to claim 1 or 2.

The powder is spirally formed on the outer peripheral surface of the upstream portion of the shaft portion with respect to the immediate upstream portion, and the powder is conveyed to the one by the rotation of the shaft portion, and the outer diameter is larger than the outer diameter of the second blade. The third blade,
The transport device according to any one of claims 1 to 3.

The spiral pitch of the third blade is larger than the spiral pitch of the second blade.
The transport device according to claim 4.

The number of rows of the third blade is larger than the number of rows of the second blade.
The transport device according to claim 4 or 5.

The developing apparatus as a conveying apparatus according to any one of claims 1 to 6, wherein a developing agent as a powder is conveyed and developed with the developing agent.

A holder that holds a latent image and
The developing apparatus according to claim 7, which develops the latent image, and
A transfer unit that transfers the image developed by the developing device to a recording medium, and
An image forming apparatus comprising.