JP2018087924A - Developer conveyance member, development device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developer conveyance member, a development device, and an image forming apparatus capable of suppressing a decrease in conveyance performance, improving stirring performance, and suppressing rapid variation in a liquid level of developer.SOLUTION: A developer conveyance member disposed in a development device for conveying developer comprises: a rotary shaft 210 having a rotary shaft AX, which can rotate around the rotary shaft AX; and an auger 220 spirally provided on a peripheral surface of the rotary shaft 210, which rotates to convey the developer. The auger 220 is configured such that each section configuring the auger 220 draws a circular locus with a rotational center O1 as a center when viewed from a direction of the rotary shaft AX according as the rotary shaft 210 rotates, and the rotary shaft 210 includes an eccentric part having a gravity center C1 having a cross-sectional shape which is orthogonal to the rotary shaft AX at a position shifted from the rotary shaft AX at least partially in the direction of the rotary shaft AX.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a developer conveying member, a developing device, and an image forming apparatus.

  In general, in an image forming apparatus, an image carrier having a photoconductive substance is uniformly charged by a charging unit, and the surface is exposed by an exposing unit to form an electrostatic latent image with the potential difference. The electrostatic latent image is converted into a toner image by a developing device, transferred to a transfer material such as paper, and then fixed using heat or pressure to form a toner image on the transfer material.

  The image carrier is charged and discharged by applying a voltage of about 4500 to 6500 [V] as a direct current or alternating current to a corona charger or a charging roller.

  In addition, in order to clean the transfer residual toner not transferred onto the transfer material but remaining on the image carrier, the image carrier is brought into contact with a cleaning blade, a cleaning brush, a cleaning roller or the like as a cleaning means. The transfer residual toner on the body surface is scraped off.

  On the other hand, a developing device that converts an electrostatic latent image into a toner image generally uses an electrostatic force to remove toner particles from a developer carrier called a developing roller close to the image carrier. Visualize by flying toner.

  At this time, the developing device generally takes a mixing and stirring form in which a charging phenomenon due to friction occurs by mixing a magnetic material called a carrier and toner particles, thereby ensuring a desired toner charge amount. is there.

  The developing device includes, for example, a replenishment area for replenishing toner and a circulation agitation area filled with the developer. In the circulation stirring region, a transport member including an auger for transporting the developer while stirring is provided.

  By the conveying member, the toner and the developer are conveyed while being mixed from the inside of the circulating stirring region to the developing roller. On the other hand, the developer remaining on the developing roller after being used to form the toner image is collected from the developing roller and conveyed to the replenishment area. Toner is supplied to the developer conveyed to the replenishment area. The developer supplied with the toner is again conveyed to the developing roller by the conveying member.

  In such a configuration, in order to eliminate image noise such as fogging and density unevenness due to poor mixing of the toner and the developer, a means for improving the stirring property has been conventionally proposed.

  For example, a conveyance member has been proposed in which a protruding paddle is provided on the opposite side of the conveyance surface of an auger for conveying developer and the like. By applying the rotational force of the conveying member to the developer that has passed over the auger by the paddle, the developer is given a force to move in the circumferential direction. This stirs the developer.

  Even in such a case, when the paddle has a general plate shape, a rapid circumferential force acts on the developer, so that the conveying force by the auger escapes in the circumferential direction. As a result, the transport speed for feeding the developer in the longitudinal direction of the transport member decreases.

  Therefore, in the conveyance member disclosed in Japanese Patent Application Laid-Open No. 2010-39169 (Patent Document 1), the paddle part for diffusing the developer is curved, and an effect of scattering the toner by supplying the toner is attempted.

  Moreover, in the conveyance member of Unexamined-Japanese-Patent No. 2014-92731 (patent document 2), the outer diameter of an auger is decentered by changing the outer diameter of an auger continuously in a longitudinal direction. Although the purpose is to suppress vibrations, it is possible to improve the diffusibility by using the turbulent flow outside the auger.

  In addition, in the transport member disclosed in Japanese Patent Application Laid-Open No. 11-15245 (Patent Document 3), the rotating shafts arranged in an eccentric position with respect to the auger are arranged in parallel to prevent interference between adjacent augers. Stirability is improved.

JP 2010-39169 A JP 2014-92731 A Japanese Patent Laid-Open No. 11-15245

  However, in the configuration disclosed in Patent Document 1, although the mixing property of the toner and the carrier in the developer is improved, the paddle itself has a strong movement force in the rotation direction, so that the force in the longitudinal conveyance direction is cyclic. And the developer transportability is lowered.

  In the configuration disclosed in Patent Document 2, it is needless to say that the gap between the outer peripheral locus of the auger and the housing is intermittently generated, and the transportability in a wide space portion is deteriorated.

  In the configuration disclosed in Patent Document 3, it is apparent that the ability to transport the developer itself is significantly reduced due to a large space fluctuation with the housing due to the eccentricity of the auger itself.

  The present invention has been made in view of the above problems, and an object of the present invention is to suppress a decrease in transportability, increase agitation, and suppress fluctuations in the developer level. It is an object of the present invention to provide a developer conveying member, a developing device, and an image forming apparatus capable of achieving the above.

  A developer transport member according to a first aspect of the present invention is a developer transport member that is disposed in a developing device and transports a developer, and has a rotation shaft and is rotatable around the rotation shaft. A shaft, and an auger provided spirally on the peripheral surface of the rotating shaft and transporting the developer by rotating, and the auger is viewed from the direction of the rotating shaft when the rotating shaft rotates. Each part of the auger is configured to draw a circular trajectory centered on the rotation center, and the rotation shaft is at least partially in the rotation axis direction at a position shifted from the rotation axis. An eccentric portion having a center of gravity having a cross-sectional shape perpendicular to the rotation axis is included.

  In the developer conveying member according to the first aspect of the present invention, the cross-sectional shape of the eccentric portion may be a circular shape, an elliptical shape, or an egg shape.

  In the developer conveying member according to the first aspect of the present invention, the cross-sectional shape of the eccentric portion includes a first surface facing the front side in the rotational direction of the rotary shaft, and a rear side in the rotational direction. And a second surface that faces. In this case, it is preferable that the first surface has a curved shape that bulges forward in the rotational direction.

  In the developer conveying member according to the first aspect of the present invention, the eccentric portion may include a first eccentric portion and a second eccentric portion arranged along the rotation axis direction. In this case, the cross-sectional shape in the first eccentric portion may be a circular shape, an elliptical shape, or an egg shape, and the cross-sectional shape in the second eccentric portion is forward in the rotation direction of the rotary shaft. You may have the 1st surface which faces the side, and the 2nd surface which faces the back side of the above-mentioned rotation direction. Furthermore, the first surface may have a curved shape that bulges in the rotational direction.

  In the developer conveying member according to the first aspect of the present invention, the cross-sectional shape of the eccentric portion may be constant along the rotation axis direction.

  In the developer conveying member according to the first aspect of the present invention, the eccentric portion has a shape in which the cross-sectional shape is continuously rotated around the rotation axis along the rotation axis direction. May be.

  In the developer conveying member according to the first aspect of the present invention, the eccentric portion may include a first eccentric portion and a second eccentric portion that are adjacent to each other along the rotation axis direction. In this case, the cross-sectional shape of each of the first eccentric portion and the second eccentric portion may be constant along the rotation axis direction. Furthermore, the cross-sectional shape of the first eccentric portion may coincide with a shape obtained by rotating the cross-sectional shape of the second eccentric portion around the rotation axis.

  In the developer conveying member according to the first aspect of the present invention, the eccentric portion may include a first eccentric portion and a second eccentric portion arranged along the rotation axis direction. In this case, the cross-sectional shape of the first eccentric portion may be different from the cross-sectional shape of the second eccentric portion.

  In the developer conveying member according to the first aspect of the present invention, in the cross-sectional shape of the eccentric portion, a straight line connecting the center of gravity and the rotation axis is positioned with respect to the rotation axis. When the point intersecting the cross-sectional shape on the side is defined as the cross-center of gravity center, the center of gravity of the cross-sectional shape is between the rotary shaft and the mid-point of the cross-center of gravity side and the rotation axis in the cross-sectional shape. May be located.

  In the developer conveying member according to the first aspect of the present invention, the cross-sectional shape of the eccentric portion includes a curved arc portion and a connecting portion that connects both ends of the arc portion. Also good. In this case, when viewed from the rotational axis direction, in the cross-sectional shape, the first straight line that is parallel to the straight line connecting the center of the arc portion and the center of gravity and passes through the rotational axis, When the circular locus of the auger is partitioned by a second straight line that is orthogonal to the first straight line and passes through the rotation axis, the center of gravity of the cross-sectional shape at the eccentric portion is The side located on the side opposite to the side where the connecting portion is located, and the rear side in the rotational direction with respect to the first straight line of the portion located on the side opposite to the side where the connecting portion is located relative to the second straight line It may be located on the side.

  A developer transport member according to a second aspect of the present invention is a developer transport member that is disposed in a developing device and transports a developer, and has a rotation shaft and is rotatable around the rotation shaft. A shaft, and an auger provided spirally on the peripheral surface of the rotating shaft and transporting the developer by rotating, and the auger is viewed from the direction of the rotating shaft when the rotating shaft rotates. In this case, each part constituting the auger is configured to draw a circular trajectory centered on the rotation center, and the rotation shaft has a center of gravity of a cross-sectional shape of the rotation shaft perpendicular to the rotation axis. And a region where the center of gravity of the cross-sectional shape is located away from the rotation axis.

  The developer conveying member according to the third aspect of the present invention is a developer conveying member that is disposed in the developing device and conveys the developer, and each has a rotation shaft and rotates about each of the rotation shafts. A first rotating shaft and a second rotating shaft that are possible, a first auger that is spirally provided on the circumferential surface of the first rotating shaft and conveys the developer by rotating; and a circumferential surface of the second rotating shaft And a second auger that conveys the developer by rotating, and the first auger is rotated when the first rotating shaft is rotated so that the first auger is viewed from the rotation axis direction. Each part constituting the first auger is configured to draw a circular trajectory centered on the rotation center, and the second auger is viewed from the rotation axis direction when the second rotation shaft rotates. If above Each part constituting one auger is configured to draw a circular trajectory centered on the rotation center, and the rotation axis of the first rotation shaft is opposed to and parallel to the rotation axis of the second rotation shaft. And at least one of the first rotating shaft and the second rotating shaft has a center of gravity having a cross-sectional shape perpendicular to the rotating shaft at a position shifted from the rotating shaft at least partially in the rotating shaft direction. Includes eccentric part.

  A developing device according to the present invention includes the developer conveying member described above and an accommodating portion that accommodates the developer conveying member.

  An image forming apparatus according to the present invention includes the above developing device and an image carrier that carries a toner image developed by the developing device.

  According to the present invention, there are provided a developer transport member, a developing device, and an image forming apparatus capable of suppressing a decrease in transportability, increasing agitation, and suppressing a fluctuation in developer level. be able to.

1 is a schematic sectional view of an image forming apparatus according to Embodiment 1. FIG. 1 is a schematic cross-sectional view of a developing device according to a first embodiment. 3 is a schematic cross-sectional view of a developer conveying member according to Embodiment 1. FIG. FIG. 6 is a diagram illustrating a state where the developer transport member according to the first embodiment is in a first position. It is sectional drawing along the VV line shown in FIG. It is sectional drawing along the VI-VI line shown in FIG. It is sectional drawing along the VII-VII line shown in FIG. It is sectional drawing along the VIII-VIII line shown in FIG. FIG. 7 is a diagram illustrating a state where the developer transport member according to the first embodiment is in a second position. It is sectional drawing along the XX line shown in FIG. FIG. 10 is a diagram illustrating a state where the developer transport member according to the first embodiment is in a third position. It is sectional drawing along the XII-XII line | wire shown in FIG. FIG. 10 is a diagram illustrating a state where the developer conveying member according to the first embodiment is in a fourth position. It is sectional drawing along the XIV-XIV line | wire shown in FIG. 6 is a diagram illustrating a first state in which the developer is transported by the developer transport member according to Embodiment 1. FIG. FIG. 10 is a diagram illustrating a second state in which the developer is transported by the developer transport member according to the first embodiment. FIG. 10 is a diagram illustrating a third state in which the developer is transported by the developer transport member according to the first embodiment. FIG. 10 is a diagram illustrating a fourth state in which the developer is transported by the developer transport member according to the first embodiment. FIG. 6 is a diagram for explaining a pressing force acting in a rotation axis direction when the developer conveying member according to the first embodiment rotates. FIG. 6 is a diagram for explaining a pressing force acting in a plane direction perpendicular to a rotation axis when the developer transport member according to the first embodiment rotates. It is a schematic sectional drawing of the developer conveyance member which concerns on the form of a comparison. It is a figure which shows the 1st state which conveys a developer by the developer conveyance member which concerns on the form of a comparison. It is a figure which shows the 2nd state which conveys a developer by the developer conveyance member which concerns on the form of a comparison. It is a figure which shows the 3rd state which conveys a developer by the developer conveyance member which concerns on the form of a comparison. It is a figure which shows the 4th state which conveys a developer by the developer conveyance member which concerns on the form of a comparison. 6 is a schematic cross-sectional view of a developer conveying member according to Embodiment 2. FIG. FIG. 10 is a diagram illustrating a state where a developer conveying member according to Embodiment 2 is in a first position. FIG. 28 is a cross-sectional view taken along line XXVIII-XXVIII shown in FIG. 27. It is sectional drawing along the XXIX-XXIX line | wire shown in FIG. It is sectional drawing along the XXX-XXX line shown in FIG. FIG. 28 is a cross-sectional view taken along line XXXI-XXXI shown in FIG. 27. FIG. 10 is a diagram illustrating a state where a developer conveying member according to Embodiment 2 is in a second position. FIG. 33 is a cross-sectional view taken along line XXXIII-XXXIII shown in FIG. 32. FIG. 10 is a diagram illustrating a state where a developer conveying member according to Embodiment 2 is in a third position. FIG. 35 is a cross-sectional view taken along line XXXV-XXXV shown in FIG. 34. FIG. 10 is a diagram illustrating a state where a developer conveying member according to Embodiment 2 is in a fourth position. FIG. 37 is a cross-sectional view taken along line XXXVII-XXXVII shown in FIG. 36. 6 is a schematic cross-sectional view of a developer conveying member according to Embodiment 3. FIG. FIG. 10 is a diagram illustrating a state where a developer conveying member according to Embodiment 3 is in a first position. It is sectional drawing along the XL-XL line shown in FIG. It is sectional drawing along the XLI-XLI line shown in FIG. It is sectional drawing along the XLII-XLII line shown in FIG. FIG. 40 is a cross-sectional view taken along line XLIII-XLIII shown in FIG. 39. FIG. 10 is a diagram illustrating a state where a developer conveying member according to Embodiment 3 is in a second position. It is sectional drawing along the XLV-XLV line shown in FIG. FIG. 10 is a diagram illustrating a state where a developer conveying member according to Embodiment 3 is in a third position. It is sectional drawing along the XLVII-XLVII line shown in FIG. FIG. 10 is a diagram illustrating a state where a developer conveying member according to Embodiment 3 is in a fourth position. It is sectional drawing along the XLIX-XLIX line | wire shown in FIG. 6 is a schematic cross-sectional view of a developer conveying member according to Embodiment 4. FIG. FIG. 10 is a diagram illustrating a state where a developer conveying member according to a fifth embodiment is in a first position. It is sectional drawing along the LII-LII line | wire shown in FIG. FIG. 52 is a cross-sectional view taken along line LIII-LIII shown in FIG. 51. It is sectional drawing along the LIV-LIV line | wire shown in FIG. It is sectional drawing along the LV-LV line shown in FIG. FIG. 52 is a cross-sectional view taken along line LVI-LVI shown in FIG. 51. FIG. 10 is a diagram illustrating a state where a developer conveying member according to a fifth embodiment is in a second position. FIG. 58 is a cross-sectional view taken along line LVIII-LVIII shown in FIG. 57. FIG. 58 is a cross-sectional view along the line LIX-LIX shown in FIG. 57. FIG. 58 is a cross-sectional view taken along line LX-LX shown in FIG. 57. FIG. 58 is a cross-sectional view taken along line LXI-LXI shown in FIG. 57. It is sectional drawing along the LXII-LXII line | wire shown in FIG. FIG. 10 is a diagram illustrating a state where a developer conveying member according to a fifth embodiment is in a third position. FIG. 64 is a cross-sectional view taken along line LXIV-LXIV shown in FIG. 63. FIG. 64 is a cross-sectional view taken along line LXV-LXV shown in FIG. 63. FIG. 64 is a cross-sectional view taken along line LXVI-LXVI shown in FIG. 63. FIG. 64 is a cross-sectional view taken along line LXVII-LXVII shown in FIG. 63. FIG. 64 is a cross-sectional view taken along line LXVIII-LXVIII shown in FIG. 63. FIG. 10 is a diagram illustrating a state where a developer transport member according to a fifth embodiment is in a fourth position. FIG. 70 is a cross-sectional view taken along line LXX-LXX shown in FIG. 69. FIG. 70 is a cross-sectional view taken along line LXXI-LXXI shown in FIG. 69. FIG. 70 is a cross-sectional view taken along line LXXII-LXXII shown in FIG. 69. FIG. 70 is a cross-sectional view taken along line LXXIII-LXXIII shown in FIG. 69. FIG. 70 is a cross-sectional view taken along line LXXIV-LXXIV shown in FIG. 69. FIG. 10 is a diagram illustrating a developer conveying member according to a sixth embodiment. FIG. 76 is a cross-sectional view taken along line LXXVI-LXXVI shown in FIG. 75. FIG. 10 is a diagram illustrating a state where a developer conveying member according to a sixth embodiment is in a first position. FIG. 78 is a cross-sectional view taken along line LXXVIII-LXXVIII shown in FIG. 77. FIG. 78 is a cross-sectional view taken along line LXXIX-LXXIX shown in FIG. 77. FIG. 78 is a cross-sectional view taken along line LXXX-LXXX shown in FIG. 77. FIG. 78 is a cross-sectional view taken along line LXXXI-LXXXI shown in FIG. 77. FIG. 10 is a cross-sectional view illustrating a state where a developer conveying member according to a sixth embodiment is in a second position. FIG. 83 is a cross sectional view taken along a line LXXXIII-LXXXIII shown in FIG. 82. FIG. 10 is a diagram illustrating a state where a developer conveying member according to a sixth embodiment is in a third position. FIG. 85 is a cross sectional view taken along a line LXXXV-LXXXV shown in FIG. 84. FIG. 10 is a diagram illustrating a state where a developer conveying member according to a sixth embodiment is in a fourth position. FIG. 87 is a cross sectional view taken along line LXXXVII-LXXXVII shown in FIG. 86. FIG. 10 is a diagram illustrating a developer conveying member according to a seventh embodiment. FIG. 89 is a cross sectional view taken along line LXXXIX-LXXXIX shown in FIG. 88. It is sectional drawing along the XC-XC line | wire shown in FIG. FIG. 89 is a cross-sectional view taken along line XCI-XCI shown in FIG. 88. It is sectional drawing along the XCII-XCII line | wire shown in FIG. FIG. 10 is a diagram illustrating a developer conveying member according to an eighth embodiment. FIG. 94 is a cross-sectional view taken along line XCIV-XCIV shown in FIG. 93. FIG. 94 is a cross-sectional view taken along line XCV-XCV shown in FIG. 93. FIG. 94 is a cross-sectional view taken along line XCVI-XCVI shown in FIG. 93. FIG. 94 is a cross-sectional view taken along line XCVII-XCVII shown in FIG. 93. FIG. 10 is a view illustrating a peripheral structure of a developer conveying member according to a ninth embodiment. FIG. 12 is a cross-sectional view perpendicular to the rotation axis direction of a developing device according to a tenth embodiment. It is sectional drawing along CC line shown in FIG. FIG. 12 is a cross-sectional view of a developing device according to Embodiment 11 that is parallel to the rotation axis direction. FIG. 16 is a cross-sectional view of a developing device according to Embodiment 12 that is parallel to the rotation axis direction. It is a figure which shows the movement amount of the developer which moves to the plane direction perpendicular | vertical to a rotating shaft in the simulation performed in order to verify the effect which concerns on embodiment. It is a figure which shows the movement amount of the developer which moves to the circumferential direction in the simulation performed in order to verify the effect which concerns on embodiment. It is a figure which shows the movement amount of the developer which moves to the direction parallel to a rotating shaft in the simulation performed in order to verify the effect which concerns on embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, the same or common parts are denoted by the same reference numerals in the drawings, and description thereof will not be repeated. In the embodiment described below, the case where the image forming apparatus is a color printer will be described as an example. However, the present invention is not limited to this, and the image forming apparatus may be a monochrome printer or by fax. It may be a monochrome printer, a color printer, and a multi-function peripheral (MFP).

(Embodiment 1)
FIG. 1 is a schematic diagram of an image forming apparatus according to the first embodiment. An image forming apparatus 100 according to Embodiment 1 will be described with reference to FIG.

  As shown in FIG. 1, an image forming apparatus 100 according to Embodiment 1 includes image forming units 1Y, 1M, 1C, and 1K, an intermediate transfer belt 30, a primary transfer roller 31, a secondary transfer roller 33, A cassette 37, a driven roller 38, a driving roller 39, a timing roller 40, a fixing device 50, and a control unit 101 are provided.

  The image forming units 1Y, 1M, 1C, and 1K are arranged in order along the intermediate transfer belt 30. The image forming unit 1Y receives toner from the toner bottle 15Y and forms a yellow (Y) toner image. The image forming unit 1M receives the supply of toner from the toner bottle 15M and forms a magenta (M) toner image. The image forming unit 1C receives toner from the toner bottle 15C and forms a cyan (C) toner image. The image forming unit 1K receives toner from the toner bottle 15K and forms a black (BK) toner image.

  The image forming units 1Y, 1M, 1C, and 1K are arranged along the intermediate transfer belt 30 in the rotation direction of the intermediate transfer belt 30, respectively. Each of the image forming units 1Y, 1M, 1C, and 1K includes a photoconductor 10, a charging device 11, an exposure device 12, a developing device 13, and a cleaning device 17.

  The charging device 11 uniformly charges the surface of the photoconductor 10. The exposure device 12 irradiates the photoreceptor 10 with laser light in accordance with a control signal from the control unit 101, and exposes the surface of the photoreceptor 10 in accordance with the input image pattern. Thereby, an electrostatic latent image corresponding to the input image is formed on the photoreceptor 10.

  The developing device 13 applies a developing bias to the developing roller 14 while rotating the developing roller 14, and causes the toner to adhere to the surface of the developing roller 14. As a result, the toner is transferred from the developing roller 14 to the photoreceptor 10, and a toner image corresponding to the electrostatic latent image is developed on the surface of the photoreceptor 10.

  The photoconductor 10 and the intermediate transfer belt 30 are in contact with each other at a portion where the primary transfer roller 31 is provided. The primary transfer roller 31 has a roller shape and is configured to be rotatable. A transfer voltage having a polarity opposite to that of the toner image is applied to the primary transfer roller 31, whereby the toner image is transferred from the photoreceptor 10 to the intermediate transfer belt 30. A yellow (Y) toner image, a magenta (M) toner image, a cyan (C) toner image, and a black (BK) toner image are sequentially superimposed and transferred from the photoreceptor 10 to the intermediate transfer belt 30. As a result, a color toner image is formed on the intermediate transfer belt 30.

  The intermediate transfer belt 30 is stretched around a driven roller 38 and a driving roller 39. The drive roller 39 is rotationally driven by, for example, a motor (not shown). The intermediate transfer belt 30 and the driven roller 38 rotate in conjunction with the driving roller 39. As a result, the toner image on the intermediate transfer belt 30 is conveyed to the secondary transfer roller 33.

  The cleaning device 17 is in pressure contact with the photoreceptor 10. The cleaning device 17 collects the toner remaining on the surface of the photoreceptor 10 after the transfer of the toner image.

  A sheet S is set in the cassette 37. As the paper S, concavo-convex paper or plain paper can be adopted. The paper type of the paper S is detected by a paper type detection unit 60 as a paper information acquisition unit provided on the conveyance path 41 up to the fixing device 50. Note that the paper type detection unit 60 may be provided in the cassette 37.

  The sheets S are sent one by one from the cassette 37 to the secondary transfer roller 33 along the transport path 41 by the timing roller 40. The secondary transfer roller 33 has a roller shape and is configured to be rotatable. The secondary transfer roller 33 applies a transfer voltage having a polarity opposite to that of the toner image to the sheet S being conveyed. As a result, the toner image is attracted from the intermediate transfer belt 30 to the secondary transfer roller 33, and the toner image on the intermediate transfer belt 30 is transferred. The conveyance timing of the sheet S to the secondary transfer roller 33 is adjusted by the timing roller 40 in accordance with the position of the toner image on the intermediate transfer belt 30. The toner image on the intermediate transfer belt 30 is transferred to an appropriate position on the paper S by the timing roller 40.

  The fixing device 50 pressurizes and heats the paper S passing through the fixing device 50. As a result, the toner image is fixed on the paper S. Thereafter, the sheet S is discharged to the tray 48. The control unit 101 is configured by an electric circuit including a CPU and the like, and controls operations of the fixing device and the like.

  In the above description, the image forming apparatus 100 adopting the tandem method as the printing method has been described. However, the printing method of the image forming apparatus 100 is not limited to the tandem method. The arrangement of the components in the image forming apparatus 100 can be changed as appropriate according to the employed printing method. As a printing method of the image forming apparatus 100, a rotary method or a direct transfer method may be employed. In the case of the rotary system, the image forming apparatus 100 includes a single photoconductor 10 and a plurality of developing devices 13 configured to be coaxially rotatable. At the time of printing, the image forming apparatus 100 guides each developing device 13 to the photoreceptor 10 in order to develop each color toner image. In the case of the direct transfer method, the image forming apparatus 100 directly transfers the toner image formed on the photoreceptor 10 onto the paper S. Further, a cleaning-less method without a cleaning unit may be used.

  FIG. 2 is a schematic cross-sectional view of the developing device according to the first embodiment. With reference to FIG. 2, the developing device 13 according to the first embodiment will be described.

  The developing device 13 includes a housing 130, a developing roller 14, a first developer transport member 21, and a second developer transport member 22. The housing 130 includes a first housing part 131, a second housing part 132, and a developing roller housing part 133. The housing 130 includes a wall portion 134, and the first accommodation portion 131 and the second accommodation portion 132 are partitioned by the wall portion 134.

  The first developer conveying member 21 is accommodated in the first accommodating portion 131. The second developer conveying member 22 is accommodated in the second accommodating portion 132. The first developer conveying member 21 and the second developer conveying member 22 are arranged side by side in the left-right direction, for example. A developing roller 14 is disposed in the developing roller storage portion 133. The developing roller 14 is located above the first developer transport member 21.

  A so-called two-component developer in which toner and carrier are mixed is accommodated in the housing 130. The developer moves by the second developer conveying member 22 and the first developer conveying member 21 so as to circulate between the second accommodating portion 132 and the first accommodating portion 131.

  A plurality of magnetic pole bodies (not shown) are arranged inside the developing roller 14. The developing roller 14 receives the developer conveyed by the first developer conveying member 21 by magnetic force. The developer that has moved to the outer peripheral surface of the developing roller is adjusted to the target surface layer amount by a regulating member (not shown).

  The adjusted developer is maintained attached to the outer peripheral surface of the developing roller 14 by a magnetic force, and the developing roller 14 rotates and is conveyed to the developing nip portion where the developing roller 14 and the photoconductor 10 face each other. The toner contained in the developer flies over the electrostatic latent image formed on the photoconductor 10. Thereby, the electrostatic latent image is visualized by the toner.

  At this time, a high voltage obtained by superimposing an AC component on a DC component is applied as a developing bias voltage in the development nip portion in order to cause the toner to fly to the photoreceptor 10. The applied voltage may be only a direct current component or an alternating current component. Further, in the development nip portion, a desired gap is required between the photoconductor 10 and the development roller 14, but the amount of the gap is arbitrary and is not particularly defined.

  Although the toner in the developing device 13 is consumed by the development, the toner is replenished from a toner supply unit (not shown) as needed, and the developer can maintain a substantially constant toner density.

  FIG. 3 is a schematic cross-sectional view of the developer transport member according to the first embodiment. FIG. 4 is a diagram illustrating a state where the developer transport member according to the first embodiment is in the first position. With reference to FIGS. 3 and 4, the first developer conveying member 21 according to the first embodiment will be described. Note that the second developer conveying member 22 is configured in substantially the same manner as the first developer conveying member 21, and thus description thereof is omitted.

  As shown in FIGS. 3 and 4, the first developer conveying member 21 includes a rotating shaft 210 and an auger 220.

  The rotation shaft 210 has a rotation axis AX and is configured to be rotatable around the rotation axis AX. The rotating shaft 210 is rotatably supported.

  The rotation shaft 210 includes an eccentric portion having a center of gravity C1 having a cross-sectional shape orthogonal to the rotation axis AX at a position shifted from the rotation axis AX. That is, the rotation shaft 210 includes a portion that is offset from the rotation axis AX when the center of gravity C1 having a cross-sectional shape orthogonal to the rotation axis AX direction is viewed from the rotation axis AX direction.

  Most of the rotating shaft 210 is constituted by an eccentric portion. In addition, all of the rotating shaft 210 may be comprised by the eccentric part, and a part of rotating shaft 210 may be comprised by the eccentric part.

  In the eccentric portion, the cross-sectional shape is constant along the direction of the rotation axis AX. The eccentric part has a cylindrical shape. In the cross-sectional shape at the eccentric portion, when the point where the straight line L1 connecting the center of gravity and the rotation axis AX intersects the cross-sectional shape on the side where the center of gravity C1 is located with respect to the rotation axis AX is the intersection point P1, the center of gravity of the cross-sectional shape C1 is located between the intersection point P1 and the intermediate point M1 of the rotation axis AX and the rotation axis AX in the cross-sectional shape.

  The auger 220 is spirally provided on the peripheral surface of the rotary shaft 210. The auger 220 conveys the developer by rotating the rotating shaft 210 around the rotation axis AX.

  FIG. 5 is a cross-sectional view taken along line VV shown in FIG. 6 is a cross-sectional view taken along line VI-VI shown in FIG. 7 is a cross-sectional view taken along line VII-VII shown in FIG. 8 is a cross-sectional view taken along line VIII-VIII shown in FIG.

  FIG. 5 shows a cross section of the first developer conveying member 21 perpendicular to the rotation axis AX direction at a position where the auger 220 faces downward in FIG.

  6 shows a cross section of the first developer conveying member 21 perpendicular to the rotation axis AX direction at a position where the auger 220 faces the back side in the direction perpendicular to the paper surface in FIG. As shown in FIG. 6, at the position where the auger 220 faces in the direction perpendicular to the paper surface in FIG. 4, the protruding amount of the auger 220 protruding in the radial direction of the rotating shaft 210 from the peripheral surface of the rotating shaft 210 is as shown in FIG. Is also getting smaller. On the other hand, in FIG. 6, the distance from the rotation center O1 of the auger 220 to the tip of the auger 220 is the same as the distance from the rotation center O1 of the auger 220 to the tip of the auger 220 in FIG.

  7 shows a cross section of the first developer conveying member 21 perpendicular to the direction of the rotation axis AX at a position where the auger 220 faces upward in FIG. As shown in FIG. 7, at the position where the auger 220 faces upward in FIG. 4, the protruding amount of the auger 220 protruding in the radial direction of the rotating shaft 210 from the peripheral surface of the rotating shaft 210 is substantially the same as FIG. 5. . In FIG. 7, the distance from the rotation center O1 of the auger 220 to the tip of the auger 220 is the same as the distance from the rotation center O1 of the auger 220 to the tip of the auger 220 in FIG.

  FIG. 8 shows a cross section of the first developer conveying member 21 perpendicular to the rotation axis AX direction at a position where the auger 220 faces the front side in the direction perpendicular to the paper surface in FIG. As shown in FIG. 8, at the position where the auger 220 faces the front side in the direction perpendicular to the paper surface in FIG. 4, the protruding amount of the auger 220 protruding in the radial direction of the rotating shaft 210 from the peripheral surface of the rotating shaft 210 is Is also slightly longer. 8, the distance from the rotation center O1 of the auger 220 to the tip of the auger 220 is the same as the distance from the rotation center O1 of the auger 220 to the tip of the auger 220 in FIG.

  By configuring the auger 220 in this way, the auger 220 is configured such that each part constituting the auger 220 is centered on the rotation center O1 when viewed from the direction of the rotation axis AX as the rotation shaft 210 rotates. It is configured to draw a circular trajectory. The rotation center O1 coincides with the rotation axis AX.

  6 to 8, the cross-sectional shape of the rotation shaft 210 perpendicular to the rotation axis AX direction is constant in the rotation axis AX direction. 6 to 8, the position of the center of gravity C1 of the cross-sectional shape of the rotation shaft 210 perpendicular to the direction of the rotation axis AX is the same, and the amount of deviation from the rotation axis AX is also the same.

  FIG. 9 is a diagram illustrating a state where the developer transport member according to the first embodiment is in the second position. 10 is a cross-sectional view taken along line XX shown in FIG. With reference to FIG. 9 and FIG. 10, the state in which the first developer conveying member 21 is in the second position will be described. In addition, the position of the cross section in FIG. 10 is the same position as the cross-sectional position along the VV line in FIG.

  As shown in FIG. 9, the second position of the first developer conveying member 21 is opposite to the first position of the first developer conveying member 21 when the rotary shaft 210 is viewed from the direction of the arrow AR shown in FIG. It is a position rotated 90 ° clockwise around the rotation axis AX.

  As shown in FIG. 10, in the cross-sectional shape at the second position, the center of gravity C1 of the cross-sectional shape is located above the rotation axis AX, and the tip of the auger 220 is located on the right side of the rotation axis AX in FIG. .

  FIG. 11 is a diagram illustrating a state where the developer transport member according to the first embodiment is in the third position. 12 is a cross-sectional view taken along line XII-XII shown in FIG. With reference to FIG. 11 and FIG. 12, a state in which the first developer conveying member 21 is in the third position will be described. In addition, the cross-sectional position in FIG. 12 is the same position as the cross-sectional position along the VV line in FIG.

  As shown in FIG. 11, the third position of the first developer conveying member 21 is opposite to the first position of the first developer conveying member 21 when the rotary shaft 210 is viewed from the direction of the arrow AR shown in FIG. It is a position rotated 180 ° clockwise around the rotation axis AX.

  As shown in FIG. 12, in the cross-sectional shape at the third position, the center of gravity C1 of the cross-sectional shape is located on the left side of the rotation axis AX in the drawing, and the tip of the auger 220 is located above the rotation axis AX.

  FIG. 13 is a diagram illustrating a state where the developer transport member according to the first embodiment is in the fourth position. 14 is a cross-sectional view taken along line XIV-XIV shown in FIG. With reference to FIGS. 13 and 14, a state in which the first developer transport member 21 is in the fourth position will be described. The cross-sectional position in FIG. 14 is the same position as the cross-sectional position along the line VV in FIG.

  As shown in FIG. 13, the fourth position of the first developer conveying member 21 is determined when the rotary shaft 210 is viewed from the direction of the arrow AR shown in FIG. 4 from the first position of the first developer conveying member 21. This is a position rotated by 270 ° around the rotation axis AX.

  As shown in FIG. 14, in the cross-sectional shape at the fourth position, the center of gravity C1 of the cross-sectional shape is located on the left side of the rotation axis AX in the drawing, and the tip of the auger 220 is located above the rotation axis AX.

  FIGS. 15 to 18 are diagrams illustrating a first state to a fourth state in which the developer is transported by the developer transport member according to the first embodiment. With reference to FIG. 15 to FIG. 18, how the first developer transport member 21 transports the developer will be described. The cross-sectional positions shown in FIGS. 15 to 18 are the same, and in FIGS. 16 to 18, the position of the liquid surface in the first state shown in FIG. 15 is indicated by a broken line.

  As shown in FIG. 15, in the first state, in the cross-sectional shape of the rotation shaft 210 perpendicular to the rotation axis AX, the center of gravity C1 of the cross-sectional shape is located below the position of the rotation axis AX. In this first state, since the position of the rotary shaft 210 is away from the developer liquid level LP, the pressing force by which the rotary shaft 210 presses the developer toward the front side in the rotation direction is applied to the liquid level LP. The effect is small. As a result, the liquid level LP of the developer becomes substantially flat.

  As shown in FIG. 16, in the second state, in the cross-sectional shape of the rotation shaft 210 perpendicular to the rotation axis AX, the center of gravity C1 of the cross-sectional shape is located on the right side of the position of the rotation axis AX. In the second state, the position of the rotary shaft 210 approaches the developer level LP as compared to the first state. As a result, the pressing force with which the rotating shaft 210 presses the developer toward the front side in the rotation direction affects the liquid level LP of the developer, and the liquid level LP on the side where the center of gravity C1 of the rotating shaft 210 is located slightly. To rise.

  As shown in FIG. 17, in the third state, in the cross-sectional shape of the rotation shaft 210 perpendicular to the rotation axis AX, the center of gravity C1 of the cross-sectional shape is located above the position of the rotation axis AX. In this third state, since the rotary shaft 210 is located on the developer liquid level LP side, the liquid level LP is thereby raised. In addition, the liquid level LP further increases due to the pressing force with which the rotating shaft 210 presses the developer toward the front side in the rotation direction. The highest position of the liquid level LP in the third state is increased by a distance D1 compared to the position of the liquid level LP in the first state indicated by a broken line in the drawing.

  As shown in FIG. 18, in the fourth state, in the cross-sectional shape of the rotation shaft 210 perpendicular to the rotation axis AX, the center of gravity C1 of the cross-sectional shape is located on the left side of the position of the rotation axis AX. In the fourth state, the position of the rotary shaft 210 is separated from the liquid level LP as compared with the third state. Further, the pressing force by the rotating shaft 210 acts downward. For this reason, in the 4th state, compared with the 3rd state, the position of liquid level LP falls.

  FIG. 19 is a diagram for explaining the pressing force acting in the rotation axis direction when the developer conveying member according to the first embodiment rotates. FIG. 20 is a diagram for explaining the pressing force acting in the plane direction perpendicular to the rotation axis when the developer transport member according to the first embodiment rotates. With reference to FIGS. 19 and 20, the force with which the first developer conveying member 21 according to the first embodiment presses the developer will be described.

  As shown in FIG. 19, when the rotary shaft 210 rotates from the first position to the fourth position, the developer is pressed by the transport surface 220a by the auger 220 moving spirally. The developer is pressed in the direction perpendicular to the transport surface 220a. That is, the transport force V is applied in the direction perpendicular to the transport surface 220a. The developer transport capability is determined by the longitudinal component of the transport force V.

  As shown in FIG. 20, when the rotary shaft 210 rotates from the first position to the fourth position, the eccentric portion in which the center of gravity and the position of the rotation shaft in the cross-sectional shape are shifted rotates, thereby causing the eccentricity. The developer is pressed by the circumferential surface on the front side in the rotational direction of the part. At a position on each circumferential surface, the developer is pressed to the outside of the circumferential surface in a direction connecting each position and the rotation axis AX. That is, the moving force VR acts radially from the rotation axis.

  Further, when the auger 220 moves spirally, a circumferential moving force Vθ according to the rotation direction of the auger 220 acts on the developer.

  By pressing the developer while applying the moving force VR and the moving force Vθ as described above, the rotating shaft 210 presses the developer while radially distributing the pressing force. Thereby, the stirrability of the developer can be improved.

  Furthermore, by dispersing the pressing force, it is possible to suppress the pressing force from being concentrated in one direction. Thereby, it is possible to suppress the developer from moving abruptly, and as a result, it is possible to suppress the fluctuation of the liquid level LP of the developer.

  Further, as the auger 220 moves spirally with the rotation of the rotary shaft 210, a conveying force is applied from the auger 220. By suppressing the rapid movement of the developer, the developer can be prevented from escaping from the tip side of the auger 220 to the outside of the auger. Thereby, a considerable amount of developer can be pressed in the vertical direction by the spiral surface of the auger 220. As a result, the component in the longitudinal direction of the conveying force V can be moved in the direction of the arrow AR in FIG. 4, and a decrease in conveying property can be suppressed.

  As described above, in the first developer conveying member 21 according to the first embodiment, it is possible to suppress the decrease in the conveying property, increase the stirring property, and suppress the fluctuation of the developer level. it can. Further, even in the developing device provided with the first developer conveying member 21 and the image forming device provided with the developing device and the image forming unit, a decrease in the conveying property is suppressed and the stirring property is increased. And the liquid level fluctuation | variation of a developing agent can be suppressed.

  Further, as described above, in the cross-sectional shape at the eccentric portion, the point where the straight line L1 connecting the center of gravity and the rotation axis AX intersects the cross-sectional shape on the side where the center of gravity C1 is located with respect to the rotation axis AX is the intersection point P1. In addition, the center of gravity C1 of the cross-sectional shape is located between the intersection P1 and the intermediate point M1 of the rotation axis AX and the rotation axis AX in the cross-sectional shape.

  As a result, when the pressing force is distributed radially as described above, the force acting on the developer as the rotating shaft 210 rotates can be gradually transmitted from the downstream side in the rotational direction to the upstream side. As a result, the developer can be efficiently stirred.

(Comparison form)
FIG. 21 is a schematic cross-sectional view of a developer transport member according to a comparative embodiment. 22 to 25 are diagrams showing a first state to a fourth state in which the developer is transported by the developer transport member according to the comparative embodiment. With reference to FIG. 21 to FIG. 25, how the first developer transport member 21 </ b> X according to the comparative form and the first developer transport member 21 </ b> X according to the comparative form transport the developer will be described. Note that the cross-sectional positions shown in FIGS. 22 to 25 are the same position, and in FIGS. 23 to 25, the position of the liquid surface in the first state shown in FIG. 22 is indicated by a broken line.

  As shown in FIG. 21, the first developer conveying member 21 </ b> X according to the comparative embodiment is provided with a paddle 230 when compared with the first developer conveying member 21 according to the first embodiment, the rotating shaft The position of 210X and the shape of the auger 220X are different.

  The rotating shaft 210X has a cylindrical shape. The center of gravity CX in the cross-sectional shape of the rotation shaft 210X in the direction perpendicular to the rotation axis AX of the rotation shaft 210X coincides with the rotation axis AX of the rotation shaft 210X. In the cross-sectional shape, the rotation center O1 of the auger 220X also coincides with the rotation axis AX of the rotation shaft 210X. Thereby, at an arbitrary position along the direction of the rotation axis AX, the distance from the peripheral surface of the rotation shaft 210X to the tip of the auger 220X is constant.

  The paddle 230 is provided so as to protrude in the radial direction of the rotary shaft 210X from the peripheral surface of the rotary shaft 210X. The paddle 230 has a plate shape. Paddle 230 extends along the direction of rotation axis AX.

  In the first developer conveying member 21X, the rotation axis AX of the rotation shaft 210X and the center of gravity C1 in the cross-sectional shape of the rotation shaft 210X coincide with each other, so that the pressing force by which the rotation shaft 210X itself presses the developer is performed. It becomes weaker than Form 1. On the other hand, by providing the paddle 230, the pressing force by the paddle 230 increases. Thereby, as a whole, the first developer conveying member 21X has a pressing force that presses the developer forward in the rotation direction of the rotary shaft 210X, as compared with the first embodiment.

  As shown in FIG. 22, in the first state, in the cross-sectional shape of the rotation shaft 210X perpendicular to the rotation axis AX, the center of gravity CX of the cross-sectional shape coincides with the position of the rotation axis AX. The paddle 230 is located below the rotation axis AX.

  In this first state, since the paddle 230 is separated from the developer liquid level LP, the pressing force by which the paddle 230 presses the developer toward the front side in the rotation direction has little influence on the liquid level LP. . As a result, the liquid level LP of the developer becomes substantially flat.

  As shown in FIG. 23, in the second state, the paddle 230 is positioned on the right side of the position of the rotation axis AX in the cross-sectional shape of the rotation shaft 210X perpendicular to the rotation axis AX. In this second state, the paddle 230 pushes up the developer forward in the rotational direction of the rotary shaft 210X. As a result, the developer level LP on the side where the paddle 230 is located is greatly increased.

  As shown in FIG. 24, in the third state, the paddle 230 is positioned above the position of the rotation axis AX in the cross-sectional shape of the rotation shaft 210X perpendicular to the rotation axis AX. In this third state, the paddle 230 is positioned closest to the liquid level LP. Thereby, the liquid level LP rises. In addition, the liquid level LP further increases due to the pressing force with which the paddle 230 presses the developer toward the front side in the rotation direction. The highest position of the liquid level LP in the third state is increased by a distance D2 compared to the position of the liquid level LP in the first state indicated by a broken line in the drawing.

  As shown in FIG. 25, in the fourth state, the paddle 230 is located on the left side of the position of the rotation axis AX in the cross-sectional shape of the rotation shaft 210X perpendicular to the rotation axis AX. The paddle 230 in the fourth state is separated from the liquid level LP as compared with the third state. Further, the pressing force by the paddle 230 acts downward. For this reason, in the 4th state, compared with the 3rd state, the position of liquid level LP falls.

  As described above, in the comparative embodiment, since the rotation axis AX of the rotary shaft 210X and the center of gravity C1 in the cross-sectional shape of the rotary shaft 210X coincide with each other, the pressing force with which the rotary shaft 210X itself presses the developer is performed. It becomes weaker than Form 1. On the other hand, by providing the paddle 230, the pressing force by the paddle 230 increases. Thereby, as a whole, the first developer conveying member 21X has a pressing force that presses the developer forward in the rotation direction of the rotary shaft 210X, as compared with the first embodiment.

  The pressing force of the developer by the paddle 230 is concentrated in the vertical direction of the paddle surface. As a result, the developer moves abruptly, and the fluctuation of the developer level LP increases. Further, due to the rapid movement of the developer, a considerable amount of developer escapes from the auger 220 to the outside of the auger 220. Thereby, the amount of the developer that can press the developer in the vertical direction by the spiral surface of the auger 220 is reduced, and the transportability is lowered.

(Embodiment 2)
FIG. 26 is a schematic cross-sectional view of the developer conveying member according to the second embodiment. FIG. 27 is a diagram illustrating a state where the developer transport member according to the second embodiment is in the first position. With reference to FIGS. 26 and 27, the first developer conveying member 21A according to the second embodiment will be described.

  As shown in FIGS. 26 and 27, the first developer conveying member 21A according to the second embodiment has an eccentric portion of the rotating shaft 210A when compared with the first developer conveying member 21 according to the first embodiment. The shape is different.

  The rotation shaft 210A includes an eccentric portion having a center of gravity C2 having a cross-sectional shape orthogonal to the rotation axis AX at a position shifted from the rotation axis AX. That is, the rotary shaft 210A includes a portion that is offset from the rotational axis AX when the center of gravity C2 having a cross-sectional shape orthogonal to the rotational axis AX direction is viewed from the rotational axis AX direction. Most of the rotating shaft 210A is formed of an eccentric portion.

  In the eccentric portion, the cross-sectional shape is constant along the direction of the rotation axis AX. The cross-sectional shape of the eccentric part is an elliptical shape. In the cross-sectional shape at the eccentric portion, when the point where the straight line L1 connecting the center of gravity and the rotation axis AX intersects the cross-sectional shape on the side where the center of gravity C2 is located with respect to the rotation axis AX is the intersection point P2, the center of gravity of the cross-sectional shape C2 is located between the intersection P2 and the intermediate point M2 of the rotation axis AX and the rotation axis AX in the cross-sectional shape.

  The auger 220 is spirally provided on the peripheral surface of the rotary shaft 210A. The auger 220 conveys the developer by rotating the rotary shaft 210A around the rotation axis AX.

  28 is a cross-sectional view taken along line XXVIII-XXVIII shown in FIG. 29 is a cross-sectional view taken along line XXIX-XXIX shown in FIG. 30 is a cross-sectional view taken along line XXX-XXX shown in FIG. 31 is a cross-sectional view taken along the line XXXI-XXXI shown in FIG.

  FIG. 28 shows a cross section of the first developer conveying member 21A perpendicular to the rotation axis AX direction at a position where the auger 220 faces the front side in the direction perpendicular to the paper surface in FIG.

  29 shows a cross section of the first developer conveying member 21A perpendicular to the direction of the rotation axis AX at the position where the auger 220 faces downward in FIG. As shown in FIG. 29, at the position where the auger 220 faces downward in FIG. 27, the protruding amount of the auger 220 protruding in the radial direction of the rotating shaft 210 from the peripheral surface of the rotating shaft 210A is substantially the same as FIG. . 29, the distance from the rotation center O1 of the auger 220 to the tip of the auger 220 is the same as the distance from the rotation center O1 of the auger 220 to the tip of the auger 220 in FIG.

  FIG. 30 shows a cross section of the first developer conveying member 21A perpendicular to the direction of the rotation axis AX at a position where the auger 220 faces in the direction perpendicular to the paper surface in FIG. As shown in FIG. 30, at the position where the auger 220 faces in the direction perpendicular to the paper surface in FIG. 27, the protruding amount of the auger 220 protruding in the radial direction of the rotating shaft 210A from the peripheral surface of the rotating shaft 210 is as shown in FIG. Is also getting smaller. On the other hand, in FIG. 30, the distance from the rotation center O1 of the auger 220 to the tip of the auger 220 is the same as the distance from the rotation center O1 of the auger 220 to the tip of the auger 220 in FIG.

  FIG. 31 shows a cross section of the first developer conveying member 21A perpendicular to the direction of the rotation axis AX at a position where the auger 220 faces upward in FIG. As shown in FIG. 31, at the position where the auger 220 faces upward in FIG. 27, the protruding amount of the auger 220 protruding in the radial direction of the rotating shaft 210 from the peripheral surface of the rotating shaft 210A is substantially the same as that in FIG. . 31, the distance from the rotation center O1 of the auger 220 to the tip of the auger 220 is the same as the distance from the rotation center O1 of the auger 220 to the tip of the auger 220 in FIG.

  By configuring the auger 220 in this manner, the auger 220 is configured such that each part of the auger 220 is centered on the rotation center O1 when viewed from the direction of the rotation axis AX as the rotation shaft 210A rotates. It is configured to draw a circular trajectory. The rotation center O1 coincides with the rotation axis AX.

  FIG. 32 is a diagram illustrating a state where the developer transport member according to the second embodiment is in the second position. FIG. 33 is a cross-sectional view taken along line XXXIII-XXXIII shown in FIG. With reference to FIGS. 32 and 33, the state where the first developer conveying member 21A is in the second position will be described. Note that the cross-sectional position in FIG. 33 is the same as the cross-sectional position along the line XXVIII-XXVIII shown in FIG.

  As shown in FIG. 32, the second position of the first developer conveying member 21A is opposite to the first position of the first developer conveying member 21A when the rotary shaft 210A is viewed from the direction of the arrow AR shown in FIG. It is a position rotated 90 ° clockwise around the rotation axis AX.

  As shown in FIG. 33, in the cross-sectional shape of the rotary shaft 210A in the second position, the center of gravity C2 of the cross-sectional shape is located above the rotation axis AX, and the tip of the auger 220 is located below the rotation axis AX. To do.

  FIG. 34 is a diagram illustrating a state where the developer transport member according to the second embodiment is in the third position. 35 is a cross-sectional view taken along line XXXV-XXXV shown in FIG. With reference to FIG. 34 and FIG. 35, a state where the first developer conveying member 21A is in the third position will be described. Note that the cross-sectional position in FIG. 33 is the same position as the cross-sectional position along the line XXXV-XXXV.

  As shown in FIG. 34, the third position of the first developer conveying member 21A is opposite to the first position of the first developer conveying member 21A when the rotary shaft 210A is viewed from the direction of the arrow AR shown in FIG. It is a position rotated 180 ° clockwise around the rotation axis AX.

  As shown in FIG. 35, in the cross-sectional shape of the rotary shaft 210A at the third position, the center of gravity C2 of the cross-sectional shape is located on the left side in FIG. 35 with respect to the rotation axis AX. It is located on the right side in FIG. 35 with respect to AX.

  FIG. 36 is a diagram illustrating a state where the developer transport member according to the second embodiment is in the fourth position. FIG. 37 is a cross-sectional view taken along line XXXVII-XXXVII shown in FIG. With reference to FIGS. 36 and 37, the state where the first developer conveying member 21A is in the fourth position will be described. The cross-sectional position in FIG. 37 is the same position as the cross-sectional position along the line XXVIII-XXVIII shown in FIG.

  As shown in FIG. 36, the fourth position of the first developer conveying member 21A is opposite to the first position of the first developer conveying member 21A when the rotary shaft 210A is viewed from the direction of the arrow AR shown in FIG. It is a position rotated 270 ° clockwise around the rotation axis AX.

  As shown in FIG. 37, in the cross-sectional shape of the rotary shaft 210A at the fourth position, the center of gravity C2 of the cross-sectional shape is located below the rotation axis AX, and the tip of the auger 220 is located above the rotation axis AX. To do.

  Even in such a configuration, the rotating shaft 210 presses the developer while distributing the pressing force radially. Thereby, the stirrability of the developer can be improved.

  Furthermore, by dispersing the pressing force, it is possible to suppress the pressing force from being concentrated in one direction. Thereby, it is possible to suppress the developer from moving abruptly, and as a result, it is possible to suppress fluctuations in the developer liquid level LP.

  Further, by suppressing the rapid movement of the developer, it is possible to prevent the developer from escaping from the tip side of the auger 220 to the outside of the auger. Thereby, a considerable amount of developer can be pressed in the vertical direction by the spiral surface of the auger 220. As a result, it is possible to move in the direction of the arrow AR in FIG. 27 by the longitudinal component of the transport force V described above, and it is possible to suppress a decrease in transportability.

  As described above, even in the first developer conveying member 21A according to the second embodiment, it is possible to suppress the deterioration of the developer level while suppressing the decrease in the conveying property and increasing the stirring property. it can.

(Embodiment 3)
FIG. 38 is a schematic cross-sectional view of the developer transport member according to the third embodiment. FIG. 39 is a diagram illustrating a state where the developer transport member according to the third embodiment is in the first position. With reference to FIGS. 38 and 39, the first developer conveying member 21B according to the third embodiment will be described.

  As shown in FIGS. 38 and 39, the first developer conveying member 21B according to the third embodiment has an eccentric portion of the rotary shaft 210B when compared with the first developer conveying member 21 according to the first embodiment. The shape is different.

  The rotation shaft 210B includes an eccentric portion having a center of gravity C3 having a cross-sectional shape orthogonal to the rotation axis AX at a position shifted from the rotation axis AX. That is, the rotation shaft 210B includes a portion that is offset from the rotation axis AX when the center of gravity C3 having a cross-sectional shape orthogonal to the rotation axis AX direction is viewed from the rotation axis AX direction. Most of the rotating shaft 210B is constituted by an eccentric portion.

  In the eccentric portion, the cross-sectional shape is constant along the direction of the rotation axis AX. The cross-sectional shape of the eccentric portion has a shape in which a part of a circle is cut in the radial direction. The cross-sectional shape in the eccentric portion has a first surface 211 facing the front side in the rotation direction of the rotation shaft 210B and a second surface 212 facing the rear side in the rotation direction. The first surface 211 has a curved shape that bulges forward in the rotational direction. The second surface 212 has a planar shape that is parallel to the rotation axis AX.

  In the cross-sectional shape at the eccentric portion, when the point where the straight line L1 connecting the center of gravity and the rotation axis AX intersects the cross-sectional shape on the side where the center of gravity C3 is located with respect to the rotation axis AX is the intersection point P3, C3 is located between the intersection P3 and the intermediate point M3 of the rotation axis AX and the rotation axis AX in the cross-sectional shape.

  The auger 220 is spirally provided on the peripheral surface of the rotating shaft 210B. The auger 220 conveys the developer by rotating the rotary shaft 210B around the rotation axis AX.

  40 is a cross-sectional view taken along line XL-XL shown in FIG. 41 is a cross-sectional view taken along line XLI-XLI shown in FIG. 42 is a cross-sectional view taken along line XLII-XLII shown in FIG. 43 is a sectional view taken along line XLIII-XLIII shown in FIG.

  40 shows a cross section of the first developer conveying member 21B perpendicular to the rotation axis AX direction at a position where the auger 220 faces the front side in the direction perpendicular to the paper surface in FIG.

  41 shows a cross section of the first developer conveying member 21B perpendicular to the direction of the rotation axis AX at a position where the auger 220 faces downward in FIG. As shown in FIG. 41, at the position where the auger 220 faces downward in FIG. 39, the protruding amount of the auger 220 protruding in the radial direction of the rotating shaft 210B from the peripheral surface of the rotating shaft 210B is slightly larger than that in FIG. ing. On the other hand, in FIG. 41, the distance from the rotation center O1 of the auger 220 to the tip of the auger 220 is the same as the distance from the rotation center O1 of the auger 220 to the tip of the auger 220 in FIG.

  42 shows a cross section of the first developer conveying member 21B perpendicular to the rotation axis AX direction at a position where the auger 220 faces the back side in the direction perpendicular to the paper surface in FIG. As shown in FIG. 42, at the position where the auger 220 faces in the direction perpendicular to the paper surface in FIG. 39, the protruding amount of the auger 220 protruding in the radial direction of the rotating shaft 210B from the peripheral surface of the rotating shaft 210B is as shown in FIG. Is also getting smaller. On the other hand, in FIG. 42, the distance from the rotation center O1 of the auger 220 to the tip of the auger 220 is the same as the distance from the rotation center O1 of the auger 220 to the tip of the auger 220 in FIG.

  FIG. 43 shows a cross section of the first developer conveying member 21B perpendicular to the direction of the rotation axis AX at a position where the auger 220 faces upward in FIG. As shown in FIG. 43, at the position where the auger 220 faces upward in FIG. 39, the protruding amount of the auger 220 protruding in the radial direction of the rotating shaft 210 from the peripheral surface of the rotating shaft 210B is substantially the same as FIG. . 43, the distance from the rotation center O1 of the auger 220 to the tip of the auger 220 is the same as the distance from the rotation center O1 of the auger 220 to the tip of the auger 220 in FIG.

  By configuring the auger 220 in this way, the auger 220 is configured such that each part of the auger 220 is centered on the rotation center O1 when viewed from the direction of the rotation axis AX as the rotation shaft 210B rotates. It is configured to draw a circular trajectory. The rotation center O1 coincides with the rotation axis AX.

  FIG. 44 is a diagram illustrating a state where the developer transport member according to the third embodiment is in the second position. 45 is a cross-sectional view taken along line XLV-XLV shown in FIG. With reference to FIGS. 44 and 45, the state where the first developer conveying member 21B is in the second position will be described. Note that the cross-sectional position in FIG. 45 is the same position as the cross-sectional position along the XL-XL line shown in FIG.

  As shown in FIG. 44, the second position of the first developer conveying member 21B is opposite to the first position of the first developer conveying member 21B when the rotary shaft 210B is viewed from the direction of the arrow AR shown in FIG. It is a position rotated 90 ° clockwise around the rotation axis AX.

  As shown in FIG. 45, in the cross-sectional shape of the rotary shaft 210B at the second position, the center of gravity C3 of the cross-sectional shape is located above the rotation axis AX, and the tip of the auger 220 is located below the rotation axis AX. To do.

  FIG. 46 is a diagram illustrating a state where the developer transport member according to the third embodiment is in the third position. 47 is a cross-sectional view taken along line XLVII-XLVII shown in FIG. With reference to FIGS. 46 and 47, the state where the first developer conveying member 21B is in the third position will be described. The cross-sectional position in FIG. 47 is the same position as the cross-sectional position along the XL-XL line shown in FIG.

  As shown in FIG. 46, the third position of the first developer conveying member 21B is opposite to the first position of the first developer conveying member 21B when the rotary shaft 210B is viewed from the direction of the arrow AR shown in FIG. It is a position rotated 180 ° clockwise around the rotation axis AX.

  As shown in FIG. 47, in the sectional shape of the rotary shaft 210B at the third position, the center of gravity C3 of the sectional shape is located on the left side in FIG. 47 with respect to the rotational axis AX, and the tip of the auger 220 is the rotational axis. It is located on the right side in FIG. 47 with respect to AX.

  FIG. 48 is a diagram illustrating a state where the developer transport member according to the third embodiment is in the fourth position. FIG. 49 is a cross-sectional view taken along line XLIX-XLIX shown in FIG. The first developer conveying member 21B will be described with reference to FIGS. 48 and 49. FIG. Note that the cross-sectional position in FIG. 49 is the same as the cross-sectional position along the line XL-XL shown in FIG.

  As shown in FIG. 48, the fourth position of the first developer transport member 21B is opposite to the first position of the first developer transport member 21B when the rotary shaft 210B is viewed from the direction of the arrow AR shown in FIG. It is a position rotated 270 ° clockwise around the rotation axis AX.

  As shown in FIG. 49, in the cross-sectional shape of the rotary shaft 210B at the fourth position, the center of gravity C3 of the cross-sectional shape is located below the rotation axis AX, and the tip of the auger 220 is located above the rotation axis AX. To do.

  Even in such a case, the first surface 211 protruding forward in the rotational direction presses the developer while radially dispersing the pressing force. Thereby, the stirrability of the developer can be improved.

  Furthermore, by dispersing the pressing force, it is possible to suppress the pressing force from being concentrated in one direction. Thereby, it is possible to suppress the developer from moving abruptly, and as a result, it is possible to suppress the fluctuation of the liquid level LP of the developer.

  Further, by suppressing the rapid movement of the developer, it is possible to prevent the developer from escaping from the tip side of the auger 220 to the outside of the auger. Thereby, a considerable amount of developer can be pressed in the vertical direction by the spiral surface of the auger 220. As a result, the component in the longitudinal direction of the conveying force V can be moved in the direction of the arrow AR in FIG. 39, and a decrease in conveying property can be suppressed.

  As described above, even in the first developer conveying member 21B according to the third embodiment, it is possible to suppress the decrease in the conveying property, increase the stirring property, and suppress the fluctuation of the developer level. it can.

  Further, in the cross-sectional shape in the eccentric portion, the cross-sectional shape described above when the straight line L1 connecting the center of gravity and the rotation axis AX intersects the cross-sectional shape on the side where the center of gravity C3 is located with respect to the rotation axis AX is the intersection point P3. Is located between the intersection point P3 and the intermediate point M3 of the rotation axis AX and the rotation axis AX in the cross-sectional shape.

  As a result, when the pressing force is distributed radially as described above, the force acting on the developer as the rotating shaft 210 rotates can be gradually transmitted from the downstream side in the rotational direction to the upstream side. As a result, the developer can be efficiently stirred.

(Embodiment 4)
FIG. 50 is a schematic cross-sectional view of the developer conveying member according to the fourth embodiment. With reference to FIG. 50, the first developer conveying member 21C according to the fourth embodiment will be described.

  As shown in FIG. 50, the first developer conveying member 21C according to the fourth embodiment is different in the cross-sectional shape of the eccentric portion when compared with the first developer conveying member 21B according to the third embodiment.

  The rotation shaft 210C includes an eccentric portion having a center of gravity C4 having a cross-sectional shape orthogonal to the rotation axis AX at a position shifted from the rotation axis AX. That is, the rotary shaft 210C includes a portion that is offset from the rotational axis AX when the center of gravity C4 having a cross-sectional shape orthogonal to the rotational axis AX direction is viewed from the rotational axis AX direction.

  In the eccentric portion, the cross-sectional shape is constant along the direction of the rotation axis AX. The cross-sectional shape of the eccentric part has a substantially crescent shape. The cross-sectional shape in the eccentric portion has a first surface 211 facing the front side in the rotation direction of the rotation shaft 210B and a second surface 212 facing the rear side in the rotation direction. The first surface 211 has a curved shape that bulges forward in the rotational direction. The second surface 212 has a curved shape that is recessed toward the front side in the rotational direction.

  In the cross-sectional shape at the eccentric portion, when the point where the straight line L1 connecting the center of gravity and the rotation axis AX intersects the cross-sectional shape on the side where the center of gravity C4 is located with respect to the rotation axis AX is the intersection point P4, C4 is located between the intersection point P4 and the intermediate point M4 of the rotation axis AX and the rotation axis AX in the cross-sectional shape.

  Even in such a case, the first developer conveying member 21C according to the fourth embodiment can obtain substantially the same effect as the first developer conveying member 21B according to the third embodiment.

(Embodiment 5)
FIG. 51 is a diagram illustrating a state where the developer transport member according to the fifth embodiment is in the first position. 52 is a cross-sectional view taken along line LII-LII shown in FIG. 53 is a cross-sectional view taken along line LIII-LIII shown in FIG. 54 is a cross-sectional view taken along line LIV-LIV shown in FIG. 55 is a cross-sectional view taken along line LV-LV shown in FIG. 56 is a cross-sectional view taken along line LVI-LVI shown in FIG. With reference to FIGS. 51 to 56, the first developer conveying member 21D according to the fifth embodiment will be described.

  As shown in FIG. 51, the first developer conveying member 21D according to the fifth embodiment is mainly different in the shape of the rotary shaft 210D when compared with the first embodiment.

  The rotation shaft 210D includes an eccentric portion having a center of gravity C5 having a cross-sectional shape orthogonal to the rotation axis AX at a position shifted from the rotation axis AX. That is, the rotation shaft 210 includes a portion that is shifted from the rotation axis AX when the center of gravity C5 having a cross-sectional shape orthogonal to the rotation axis AX direction is viewed from the rotation axis AX direction. Most of the rotating shaft 210D is constituted by an eccentric portion.

  The eccentric portion has a shape in which the cross-sectional shape is continuously rotated around the rotation axis AX along the direction of the rotation axis AX. A specific shape of the eccentric portion will be described with reference to FIGS.

  FIG. 52 shows a cross section of the first developer conveying member 21D perpendicular to the direction of the rotation axis AX at a position where the auger 220 faces downward in FIG.

  53 shows a cross section of the first developer conveying member 21D at a position where the auger 220 faces the front side in the direction perpendicular to the paper surface in FIG. As shown in FIG. 53, the cross-sectional shape of the first developer conveying member 21D at this position is obtained when the cross-sectional shape of the rotating shaft 210D in FIG. 52 is viewed from the position shown in FIG. 52 from the direction of the arrow AR shown in FIG. It is located counterclockwise at a position rotated 90 ° around the rotation axis AX.

  FIG. 54 shows a cross section of the first developer conveying member 21D at a position where the auger 220 faces the front side in the direction perpendicular to the paper surface in FIG. As shown in FIG. 54, the cross-sectional shape of the first developer conveying member 21D at this position is obtained when the cross-sectional shape of the rotary shaft 210D in FIG. 52 is viewed from the position shown in FIG. 52 from the direction of the arrow AR shown in FIG. It is located counterclockwise at a position rotated 180 ° about the rotation axis AX.

  FIG. 55 shows a cross section of the first developer conveying member 21D at the position where the auger 220 faces the front side in the direction perpendicular to the paper surface in FIG. As shown in FIG. 55, the cross-sectional shape of the first developer conveying member 21D at this position is obtained when the cross-sectional shape of the rotary shaft 210D in FIG. 52 is viewed from the position shown in FIG. 52 from the direction of the arrow AR shown in FIG. It is located counterclockwise at a position rotated 270 ° around the rotation axis AX.

  56 shows a cross section of the first developer conveying member 21D at a position where the auger 220 faces the front side in the direction perpendicular to the paper surface in FIG. As shown in FIG. 56, the cross-sectional shape of the first developer conveying member 21D at this position is obtained when the cross-sectional shape of the rotating shaft 210D in FIG. 52 is viewed from the position shown in FIG. 52 from the direction of the arrow AR shown in FIG. It is located counterclockwise at a position rotated 360 ° around the rotation axis AX.

  As described above, the eccentric portion has a shape in which a circular cross section is continuously rotated around the rotation axis AX along the direction of the rotation axis AX.

  FIG. 57 is a diagram illustrating a state where the developer transport member according to the fifth embodiment is in the second position. 58 is a cross-sectional view taken along line LVIII-LVIII shown in FIG. 59 is a cross-sectional view taken along line LIX-LIX shown in FIG. 60 is a cross-sectional view taken along line LX-LX shown in FIG. 61 is a cross-sectional view along the line LXI-LXI shown in FIG. 62 is a cross-sectional view taken along line LXII-LXII shown in FIG. The cross-sectional positions shown in FIGS. 58 to 62 are the same positions as the cross-sectional positions shown in FIGS. 52 to 56, respectively.

  As shown in FIG. 57, the second position of the first developer conveying member 21D is counterclockwise when the rotary shaft 210D is viewed from the direction of the arrow AR shown in FIG. 51 from the first position of the first developer conveying member 21D. This is a position rotated 90 ° around the rotation axis AX.

  Each of the cross-sectional shapes of the first developer conveying member 21D in FIGS. 58 to 62 is opposite to the cross-sectional shape of the first developer conveying member 21D in FIGS. 52 to 56 when viewed from the direction of the arrow AR shown in FIG. It is located at a position rotated 90 ° clockwise around the rotation axis AX.

  FIG. 63 is a diagram illustrating a state where the developer transport member according to the fifth embodiment is in the third position. 64 is a cross-sectional view taken along line LXIV-LXIV shown in FIG. FIG. 65 is a cross-sectional view along the line LXV-LXV shown in FIG. 66 is a cross-sectional view taken along line LXVI-LXVI shown in FIG. 67 is a cross-sectional view taken along line LXVII-LXVII shown in FIG. 68 is a cross-sectional view taken along line LXVIII-LXVIII shown in FIG.

  As shown in FIG. 63, the third position of the first developer conveying member 21D is counterclockwise when the rotary shaft 210D is viewed from the direction of the arrow AR shown in FIG. 51 from the first position of the first developer conveying member 21D. This is a position rotated 180 ° around the rotation axis AX.

  Each of the cross-sectional shapes of the first developer conveying member 21D in FIGS. 64 to 68 is opposite to the cross-sectional shape of the first developer conveying member 21D in FIGS. 52 to 56 when viewed from the arrow AR direction shown in FIG. It is located at a position rotated 180 ° clockwise around the rotation axis AX.

  FIG. 69 is a diagram illustrating a state where the developer transport member according to the fifth embodiment is in the fourth position. 70 is a cross-sectional view taken along line LXX-LXX shown in FIG. 69. 71 is a cross-sectional view taken along line LXXI-LXXI shown in FIG. 72 is a cross-sectional view taken along line LXXII-LXXII shown in FIG. 69. 73 is a cross-sectional view taken along line LXXIII-LXXIII shown in FIG. 69. 74 is a cross-sectional view along the line LXXIV-LXXIV shown in FIG.

  As shown in FIG. 69, the fourth position of the first developer conveying member 21D is counterclockwise when the rotary shaft 210D is viewed from the direction of the arrow AR shown in FIG. 51 from the first position of the first developer conveying member 21D. This is a position rotated by 270 ° around the rotation axis AX.

  As shown in FIGS. 70 to 74, each of the cross-sectional shapes of the first developer transport member 21D in FIGS. 70 to 74 is the cross-sectional shape of the first developer transport member 21D in FIGS. When viewed from the direction of the arrow AR shown, it is located at a position rotated 270 ° around the rotation axis AX counterclockwise.

  Even when configured as described above, the rotating shaft 210D presses the developer while radially distributing the pressing force. Thereby, the stirrability of the developer can be improved.

  Furthermore, by dispersing the pressing force, it is possible to suppress the pressing force from being concentrated in one direction. Thereby, it is possible to suppress the developer from moving abruptly, and as a result, it is possible to suppress the fluctuation of the liquid level LP of the developer.

  Further, by suppressing the rapid movement of the developer, it is possible to prevent the developer from escaping from the tip side of the auger 220 to the outside of the auger. Thereby, a considerable amount of developer can be pressed in the vertical direction by the spiral surface of the auger 220. As a result, the component in the longitudinal direction of the conveying force V can be moved in the direction of the arrow AR in FIG. 51, and a decrease in conveying property can be suppressed.

  As described above, even in the first developer conveying member 21B according to the fifth embodiment, it is possible to suppress the decrease in the conveying property, increase the stirring property, and suppress the fluctuation of the developer level. it can.

  Further, in the cross-sectional shape in the eccentric portion, the cross-sectional shape described above when the straight line L1 connecting the center of gravity and the rotation axis AX intersects the cross-sectional shape on the side where the center of gravity C5 is located with respect to the rotation axis AX is the intersection point P5. The center of gravity C5 is located between the intersection point P5 and the intermediate point M5 of the rotation axis AX and the rotation axis AX in the cross-sectional shape.

  As a result, when the pressing force is distributed radially as described above, the force acting on the developer as the rotating shaft 210 rotates can be gradually transmitted from the downstream side in the rotational direction to the upstream side. As a result, the developer can be efficiently stirred.

(Embodiment 6)
FIG. 75 is a diagram illustrating a developer conveying member according to the sixth embodiment. 76 is a cross-sectional view taken along line LXXVI-LXXVI shown in FIG. FIG. 77 is a diagram illustrating a state where the developer transport member according to the sixth embodiment is in the first position. With reference to FIGS. 75 to 77, the state where the first developer conveying member 21E is in the first position will be described.

  As shown in FIGS. 75 to 77, the first developer conveying member 21E according to the sixth embodiment has a shape of the rotary shaft 210E when compared with the first developer conveying member 21 according to the first embodiment. Is different.

  The rotating shaft 210E includes a first eccentric part 213, a second eccentric part 214, a third eccentric part 215, and a fourth eccentric part 216. The 1st eccentric part 213, the 2nd eccentric part 214, the 3rd eccentric part 215, and the 4th eccentric part 216 are arrange | positioned along with the rotating shaft AX axial direction of the rotating shaft 210E. The cross-sectional shapes of the first eccentric part 213, the second eccentric part 214, the third eccentric part 215, and the fourth eccentric part 216 perpendicular to the rotational axis AX of the rotary shaft 210E are constant along the rotational axis AX. .

  78 is a cross-sectional view taken along line LXXVIII-LXXVIII shown in FIG. 77. FIG. 78 is a cross-sectional view of the first eccentric portion 213. Specifically, FIG. 78 shows a cross section of the first developer conveying member 21E perpendicular to the rotation axis AX direction at the position where the auger 220 faces the back side in the direction perpendicular to the paper surface in FIG.

  The cross-sectional shape of the first eccentric part 213 has an elliptical shape. In the cross section of the first eccentric portion 213, the center of gravity C6 of the cross sectional shape is located at a position shifted from the rotation axis AX. In the cross-sectional shape in the first eccentric portion 213, when the point where the straight line L1 connecting the center of gravity C6 and the rotation axis AX intersects the cross-sectional shape on the side where the center of gravity C6 is located with respect to the rotation axis AX is the intersection point P6, The center of gravity C6 of the cross-sectional shape is located between the intersection point P6 and the intermediate point M6 of the rotation axis AX and the rotation axis AX in the cross-sectional shape.

  79 is a cross-sectional view taken along line LXXIX-LXXIX shown in FIG. 77. FIG. 79 is a cross-sectional view of the second eccentric portion 214. Specifically, FIG. 79 shows a cross section of the first developer conveying member 21E perpendicular to the rotation axis AX direction at a position where the auger 220 faces downward in FIG. The cross-sectional shape of the second eccentric portion 214 has a shape obtained by rotating the cross-sectional shape of the first eccentric portion 213 by 90 ° clockwise around the rotation axis AX.

  80 is a cross-sectional view taken along line LXXX-LXXX shown in FIG. 77. FIG. 80 is a cross-sectional view of the third eccentric portion 215. Specifically, FIG. 80 shows a cross section perpendicular to the direction of the rotation axis AX in the position where the auger 220 faces the front side in the direction perpendicular to the paper surface in FIG. The cross-sectional shape of the third eccentric portion 215 has a shape obtained by rotating the cross-sectional shape of the second eccentric portion 214 by 90 ° clockwise around the rotation axis AX.

  81 is a cross sectional view taken along line LXXXI-LXXXI shown in FIG. FIG. 81 is a cross-sectional view of the fourth eccentric portion 216. Specifically, FIG. 81 shows a cross section of the first developer conveying member 21E perpendicular to the direction of the rotation axis AX at the position where the auger 220 faces downward in FIG. The cross-sectional shape of the fourth eccentric portion 216 has a shape obtained by rotating the cross-sectional shape of the third eccentric portion 215 by 90 ° clockwise around the rotation axis AX.

  The auger 220 is configured such that each part of the auger 220 draws a circular trajectory centered on the rotation center O1 when viewed from the direction of the rotation axis AX as the rotation shaft 210 rotates. The rotation center O1 coincides with the rotation axis AX.

  FIG. 82 is a cross-sectional view showing a state where the developer transport member according to Embodiment 6 is in the second position. FIG. 83 is a cross sectional view taken along line LXXXIII-LXXXIII shown in FIG. With reference to FIGS. 82 and 83, the state where the first developer transport member 21E is in the second position will be described. Note that the cross-sectional position in FIG. 83 is the same as the cross-sectional position along the line LXXX-LXXX shown in FIG.

  As shown in FIG. 82, the second position of the first developer conveying member 21E is counterclockwise when the rotary shaft 210E is viewed from the direction of the arrow AR shown in FIG. 77 from the first position of the first developer conveying member 21E. This is a position rotated 90 ° around the rotation axis AX.

  As shown in FIG. 83, in the cross-sectional shape of the rotary shaft 210D at the second position, the center of gravity C6 of the cross-sectional shape is located above the rotation axis AX, and the tip of the auger 220 is located below the rotation axis AX. To do.

  FIG. 84 is a diagram illustrating a state where the developer transport member according to the sixth embodiment is in the third position. FIG. 85 is a cross sectional view taken along line LXXXV-LXXXV shown in FIG. A state where the first developer conveying member 21E is in the third position will be described with reference to FIGS. Note that the cross-sectional position in FIG. 85 is the same position as the cross-sectional position along the line LXXX-LXXX shown in FIG. 77.

  As shown in FIG. 84, the third position of the first developer conveying member 21E is counterclockwise when the rotary shaft 210E is viewed from the direction of the arrow AR shown in FIG. 77 from the first position of the first developer conveying member 21E. This is a position rotated 180 ° around the rotation axis AX.

  As shown in FIG. 85, in the cross-sectional shape of the rotary shaft 210D at the second position, the center of gravity C6 of the cross-sectional shape is located on the left side in FIG. 85 with respect to the rotary axis AX, and the tip of the auger 220 It is located on the right side in FIG. 85 with respect to AX.

  FIG. 86 is a diagram illustrating a state where the developer transport member according to the sixth embodiment is in the fourth position. FIG. 87 is a cross sectional view taken along line LXXXVII-LXXXVII shown in FIG. With reference to FIGS. 86 and 87, the state where the first developer conveying member 21E is in the fourth position will be described. Note that the cross-sectional position in FIG. 85 is the same position as the cross-sectional position along the line LXXX-LXXX shown in FIG. 77.

  As shown in FIG. 86, the fourth position of the first developer conveying member 21E is counterclockwise when the rotary shaft 210E is viewed from the direction of the arrow AR shown in FIG. 51 from the first position of the first developer conveying member 21E. This is a position rotated by 270 ° around the rotation axis AX.

  As shown in FIG. 87, in the cross-sectional shape of the rotation shaft 210D at the fourth position, the center of gravity C6 of the cross-sectional shape is located below the rotation axis AX, and the tip of the auger 220 is located above the rotation axis AX. To do.

  Even when configured as described above, the rotating shaft 210E presses the developer while radially distributing the pressing force. Thereby, the stirrability of the developer can be improved.

  Furthermore, by dispersing the pressing force, it is possible to suppress the pressing force from being concentrated in one direction. Thereby, it is possible to suppress the developer from moving abruptly, and as a result, it is possible to suppress the fluctuation of the liquid level LP of the developer.

  Further, by suppressing the rapid movement of the developer, it is possible to prevent the developer from escaping from the tip side of the auger 220 to the outside of the auger. Thereby, a considerable amount of developer can be pressed in the vertical direction by the spiral surface of the auger 220. As a result, it is possible to move in the direction of the arrow AR in FIG. 77 due to the longitudinal component of the transport force V described above, and it is possible to suppress a decrease in transportability.

  In addition, a plurality of eccentric portions including a first eccentric portion 213 and a second eccentric portion 214 arranged in the direction of the rotation axis AX are provided, and a cross-sectional shape perpendicular to the rotation axis AX in the first eccentric portion 213 is provided as the second eccentricity. By matching the cross-sectional shape of the portion 214 with the shape rotated about the rotation axis, the developer can be diffused more efficiently.

(Embodiment 7)
FIG. 88 is a diagram illustrating a developer conveying member according to the seventh embodiment. With reference to FIG. 88, the first developer conveying member 21F according to the seventh embodiment will be described.

  As shown in FIG. 88, the first developer conveying member 21F according to the seventh embodiment is different in the configuration of the rotating shaft 210F when compared with the first embodiment.

  The rotating shaft 210F includes a first eccentric part 210F1 and a second eccentric part 210F2. The first eccentric portion 210F1 and the second eccentric portion 210F2 are arranged side by side along the direction of the rotation axis AX of the rotation shaft 210F. The cross-sectional shape of the first eccentric portion 210F1 perpendicular to the rotation axis AX is different from the cross-sectional shape of the second eccentric portion 210F2 perpendicular to the rotation axis AX.

  The cross-sectional shape of the first eccentric portion 210F1 has a circular shape. The first eccentric portion 210F1 has a shape in which the cross-sectional shape is continuously rotated around the rotation axis AX along the direction of the rotation axis AX. In the cross section of the first eccentric portion 210F1, the center of gravity C71 (see FIG. 89) is located at a position shifted from the rotation axis AX.

  89 is a cross-sectional view taken along line LXXXIX-LXXXIX shown in FIG. 88. Specifically, FIG. 89 shows a cross section perpendicular to the direction of the rotation axis AX at a position where the auger 220 faces upward in FIG. As shown in FIG. 89, in the cross-sectional shape of the first eccentric portion 210F1 at the above position, the center of gravity C71 of the cross-sectional shape is located on the left side in the drawing of the rotation axis AX, and the tip of the auger 220 is the rotation axis AX Located above.

  90 is a cross-sectional view taken along line XC-XC shown in FIG. Specifically, FIG. 90 shows a cross section perpendicular to the direction of the rotation axis AX at the position where the auger 220 faces the back side in the direction perpendicular to the paper surface in FIG. As shown in FIG. 90, in the cross-sectional shape of the first eccentric portion 210F1 at the above position, the center of gravity C71 of the cross-sectional shape is located above the rotation axis AX in the drawing, and the tip of the auger 220 is the rotation axis AX. Located on the right side of the figure. The protruding amount of the auger 220 protruding in the radial direction of the first eccentric portion 210F1 from the peripheral surface of the first eccentric portion 210F1 is longer than that in FIG. On the other hand, in FIG. 90, the distance from the rotation center O1 of the auger 220 to the tip of the auger 220 is the same as the distance from the rotation center O1 of the auger 220 to the tip of the auger 220 in FIG.

  The cross-sectional shape of the second eccentric part 210F2 has an elliptical shape. The cross-sectional shape of the second eccentric portion 210F2 has a certain shape along the rotation axis AX direction. In the cross section of the second eccentric portion 210F2, the center of gravity C72 (see FIG. 91) is located at a position shifted from the rotation axis AX.

  FIG. 91 is a cross sectional view taken along line XCI-XCI shown in FIG. Specifically, FIG. 91 shows a cross section perpendicular to the direction of the rotation axis AX at a position where the auger 220 faces downward in FIG. As shown in FIG. 91, in the cross-sectional shape of the second eccentric portion 210F2 at the above position, the center of gravity C72 of the cross-sectional shape is located on the right side in the drawing of the rotation axis AX, and the tip of the auger 220 is the rotation axis AX Located below.

  FIG. 92 is a cross sectional view taken along line XCII-XCII shown in FIG. Specifically, FIG. 88 shows a cross section perpendicular to the rotation axis AX direction at a position where the auger 220 faces the front side in the direction perpendicular to the paper surface. As shown in FIG. 92, in the cross-sectional shape of the second eccentric portion 210F2 at the above position, the center of gravity C72 of the cross-sectional shape is located above the rotation axis AX in the drawing, and the tip of the auger 220 is positioned on the rotation axis AX. Located on the right side of the figure. The protruding amount of the auger 220 protruding in the radial direction of the second eccentric portion 210F2 from the peripheral surface of the second eccentric portion 210F2 is substantially the same. 92, the distance from the rotation center O1 of the auger 220 to the tip of the auger 220 is the same as the distance from the rotation center O1 of the auger 220 to the tip of the auger 220 in FIG.

  Even in the case configured as described above, the rotating shaft 210F presses the developer while distributing the pressing force radially. Thereby, the stirrability of the developer can be improved.

  Furthermore, by dispersing the pressing force, it is possible to suppress the pressing force from being concentrated in one direction. Thereby, it is possible to suppress the developer from moving abruptly, and as a result, it is possible to suppress the fluctuation of the liquid level LP of the developer.

  Further, by suppressing the rapid movement of the developer, it is possible to prevent the developer from escaping from the tip side of the auger 220 to the outside of the auger. Thereby, a considerable amount of developer can be pressed in the vertical direction by the spiral surface of the auger 220. As a result, it is possible to move in the direction of the arrow AR in FIG. 77 due to the longitudinal component of the transport force V described above, and it is possible to suppress a decrease in transportability.

  In addition, a plurality of eccentric portions including a first eccentric portion 210F1 and a second eccentric portion 210F2 arranged along the direction of the rotation axis AX are provided, and a cross-sectional shape perpendicular to the rotation axis AX in the first eccentric portion 210F1 is changed to the second eccentricity. By making the shape different from the cross-sectional shape of the portion 210F2, the developer can be diffused more efficiently.

(Embodiment 8)
FIG. 93 is a diagram illustrating a developer conveying member according to the eighth embodiment. With reference to FIG. 93, the first developer conveying member 21G according to the eighth embodiment will be described.

  As shown in FIG. 93, the first developer conveying member 21G according to the eighth embodiment is different in the configuration of the rotating shaft 210G from the first developer conveying member 21F according to the seventh embodiment.

  The rotating shaft 210G includes a first eccentric part 210F1, a second eccentric part 210G2, and a third eccentric part 210G3. The first eccentric portion 210F1, the second eccentric portion 210G2, and the third eccentric portion 210G3 are arranged side by side along the direction of the rotation axis AX of the rotation shaft 210G.

  First eccentric portion 210F1 has substantially the same shape as first eccentric portion 210F1 according to the eighth embodiment.

  FIG. 94 is a cross sectional view taken along line XCIV-XCIV shown in FIG. Specifically, FIG. 94 shows a cross section perpendicular to the direction of the rotation axis AX at a position where the auger 220 faces upward in FIG. As shown in FIG. 94, in the cross-sectional shape of the first eccentric portion 210F1 at the above position, the center of gravity C81 of the cross-sectional shape is located above the rotation axis AX in the drawing, and the tip of the auger 220 is the rotation axis AX. Located above.

  95 is a cross sectional view taken along line XCV-XCV shown in FIG. Specifically, FIG. 95 shows a cross section perpendicular to the direction of the rotation axis AX in the position where the auger 220 faces the back side in the direction perpendicular to the paper surface in FIG. As shown in FIG. 95, in the cross-sectional shape of the first eccentric portion 210F1 at the above position, the center of gravity C81 of the cross-sectional shape is located above the rotation axis AX in the figure, and the tip of the auger 220 is the rotation axis AX. Located on the right side of the figure.

  The cross-sectional shapes of the second eccentric part 210G2 and the third eccentric part 210G3 are constant along the rotation axis AX.

  FIG. 96 is a cross sectional view taken along line XCVI-XCVI shown in FIG. FIG. 96 shows a cross section perpendicular to the direction of the rotation axis AX at a position facing the front side of the auger 220 in the direction perpendicular to the paper surface in FIG.

  The cross-sectional shape of the second eccentric portion 210G2 has an elliptical shape. In the cross section of the second eccentric portion 210G2, the center of gravity C82 of the cross sectional shape is located at a position shifted from the rotation axis AX. In the cross-sectional shape of the second eccentric portion 210G2, when the point where the straight line L1 connecting the center of gravity C82 and the rotation axis AX intersects the cross-sectional shape on the side where the center of gravity C6 is located with respect to the rotation axis AX is the intersection P8, The center of gravity C82 of the cross-sectional shape is located between the intersection point P8 and the intermediate point M8 of the rotation axis AX and the rotation axis AX in the cross-sectional shape.

  97 is a cross-sectional view taken along line XCVII-XCVII shown in FIG. FIG. 97 shows the cross-sectional shape of the third eccentric portion 210G3 at the position where the auger 220 faces downward in FIG. The cross-sectional shape of the third eccentric portion 210G3 has a shape obtained by rotating the cross-sectional shape of the second eccentric portion 210G2 by 90 ° clockwise around the rotation axis AX.

  Even in the case configured as described above, the rotating shaft 210G presses the developer while distributing the pressing force radially. Thereby, the stirrability of the developer can be improved.

  Furthermore, by dispersing the pressing force, it is possible to suppress the pressing force from being concentrated in one direction. Thereby, it is possible to suppress the developer from moving abruptly, and as a result, it is possible to suppress the fluctuation of the liquid level LP of the developer.

  Further, by suppressing the rapid movement of the developer, it is possible to prevent the developer from escaping from the tip side of the auger 220 to the outside of the auger. Thereby, a considerable amount of developer can be pressed in the vertical direction by the spiral surface of the auger 220. As a result, it is possible to move in the direction of the arrow AR in FIG. 93 by the longitudinal component of the transport force V described above, and it is possible to suppress a decrease in transportability.

  In addition, the first eccentric portion 210F1, the second eccentric portion 210G2, and the third eccentric portion 210G3 having the above-described shape are arranged along the direction of the rotation axis AX, so that the developer is more efficiently performed. Can diffuse.

(Embodiment 9)
FIG. 98 is a view showing the peripheral structure of the developer conveying member according to the ninth embodiment. With reference to FIG. 98, the first developer conveying member 21H according to the ninth embodiment will be described.

  The first developer conveying member 21H is assembled in the developing device. The developing device includes a drive mechanism 300 that drives the first developer conveying member 21H.

  Drive mechanism 300 includes a drive motor M, a first gear portion 310, and a second gear portion 320. The second gear unit 320 is rotationally driven by the drive motor M. The first gear part 310 is provided so as to mesh with the second gear part 320. The first gear unit 310 rotates as the second gear unit 320 rotates. The first gear portion 310 is fixed to the first developer conveying member 21H, and the first developer conveying member 21H rotates about the rotation axis AX when the first gear portion 310 rotates.

  The first developer conveying member 21H includes a rotating shaft 210H and an auger 220. The rotating shaft 210 </ b> H has a first eccentric part 213, a second eccentric part 214, a third eccentric part 215, a fourth eccentric part 216, and a support shaft 217.

  The first eccentric part 213, the second eccentric part 214, the third eccentric part 215, and the fourth eccentric part 216 have substantially the same configuration as that of the sixth embodiment. The support shafts 217 are located at both ends in the axial direction of the rotary shaft 210H. The support shaft 217 has a cylindrical shape. The center axis of the support shaft 217 coincides with the rotation axis AX of the rotation shaft 210H. That is, the center of gravity of the cross-sectional shape of the support shaft 217 orthogonal to the rotation axis AX coincides with the rotation axis AX. The support shaft 217 is rotatably supported by a bearing portion 400 provided in the developing device.

  Thus, the rotation shaft 210H includes a region where the center of gravity of the cross-sectional shape of the rotation shaft 210H orthogonal to the rotation axis AX coincides with the rotation axis AX, and a region where the center of gravity of the cross-sectional shape is located away from the rotation axis AX.

  The auger 220 is spirally provided on the peripheral surfaces of the first eccentric part 213, the second eccentric part 214, the third eccentric part 215, and the fourth eccentric part 216, and conveys the developer by rotating.

  Even when configured as described above, the rotating shaft 210H presses the developer while radially distributing the pressing force. Thereby, the stirrability of the developer can be improved.

  Furthermore, by dispersing the pressing force, it is possible to suppress the pressing force from being concentrated in one direction. Thereby, it is possible to suppress the developer from moving abruptly, and as a result, it is possible to suppress the fluctuation of the liquid level LP of the developer.

  Further, by suppressing the rapid movement of the developer, it is possible to prevent the developer from escaping from the tip side of the auger 220 to the outside of the auger. Thereby, a considerable amount of developer can be pressed in the vertical direction by the spiral surface of the auger 220. As a result, the component in the longitudinal direction of the transport force V can be moved in the direction of the rotation axis AX, and a decrease in transportability can be suppressed.

(Embodiment 10)
FIG. 99 is a cross-sectional view perpendicular to the rotation axis direction of the developing device according to the tenth embodiment. 100 is a cross-sectional view taken along the line CC shown in FIG. A developing device 13I according to the tenth embodiment will be described with reference to FIG. 99 and FIG.

  As shown in FIG. 99, in the developing device 13I, the first developer conveying member 21 and the second developer conveying member 22 are arranged side by side in the vertical direction as compared with the developing device 13 according to the first embodiment. Is mainly different.

  The first developer conveying member 21 includes a first rotating shaft 210I and a first auger 220I. The first rotation shaft 210I has a rotation axis AX1 and is configured to be rotatable around the rotation axis AX1. The cross-sectional shape of the first rotation shaft 210I perpendicular to the rotation axis AX direction has an elliptical shape. A rotation axis AX1 of the first rotation shaft 210I is opposed to a rotation axis AX2 of the second rotation shaft 250 described later and is disposed in parallel.

  The first auger 220I is spirally provided on the peripheral surface of the first rotating shaft 210I. The first auger 220I is configured such that each part of the first auger 220I draws a circular trajectory centered on the rotation center when viewed from the rotation axis AX direction when the first rotation shaft 210I rotates. Has been.

  The second developer conveying member 22 includes a second rotating shaft 250 and a second auger 260. The second rotation shaft 250 has a rotation axis AX2 and is configured to be rotatable around the rotation axis AX2. The cross-sectional shape of the second rotation shaft 250 perpendicular to the direction of the rotation axis AX2 has an elliptical shape.

  The second auger 260 is spirally provided on the peripheral surface of the second rotating shaft 250. The second auger 260 is configured such that each part of the second auger 260 draws a circular trajectory centered on the rotation center when viewed from the direction of the rotation axis AX2 when the second rotation shaft 250 rotates. Has been.

  As described above, the first developer conveying member 21 and the second developer conveying member 22 have substantially the same configuration as the first developer conveying member 21A according to the second embodiment, and the first rotating shaft 210I and the first developer conveying member 21A. At least one of the two rotation shafts 250 includes an eccentric portion having a center of gravity having a cross-sectional shape perpendicular to the rotation axis at a position deviated from the rotation axis at least at a part in the rotation axis direction.

  Even when configured as described above, the first rotating shaft 210I and the second rotating shaft 250 press the developer while radially distributing the pressing force. Thereby, the stirrability of the developer can be improved.

  Furthermore, by dispersing the pressing force, it is possible to suppress the pressing force from being concentrated in one direction. Thereby, it is possible to suppress the developer from moving abruptly, and as a result, it is possible to suppress the fluctuation of the liquid level LP of the developer.

  Further, by suppressing the rapid movement of the developer, it is possible to prevent the developer from escaping from the first auger 220I and the second auger 260 to the outside of the first auger 220I and the second auger 260. Accordingly, a considerable amount of developer can be pressed in the vertical direction by the spiral surfaces of the first auger 220I and the second auger 260. As a result, the developer can be moved in the direction of the rotation axis by the component in the longitudinal direction of the transport force V described above, and a decrease in transportability can be suppressed.

(Embodiment 11)
FIG. 101 is a cross-sectional view parallel to the rotation axis direction of the developing device according to the eleventh embodiment. With reference to FIG. 101, a developing device 13J according to Embodiment 11 will be described.

  As shown in FIG. 101, the developing device 13J according to the eleventh embodiment is different from the developing device 13I according to the tenth embodiment in the shape of the second rotating shaft 250J in the second developer conveying member 22J. . Other configurations are almost the same.

  The second developer conveying member 22J includes a second rotating shaft 250J and a second auger 260. The second rotating shaft 250J has a first eccentric part 250J1 and a second eccentric part 250J2. First eccentric portion 250J1 is configured in substantially the same manner as the eccentric portion of rotary shaft 210A according to the second embodiment. Second eccentric portion 250J2 is configured in substantially the same manner as the eccentric portion of rotary shaft 210D according to the fifth embodiment.

  Even in such a case, the developing device 13J according to the eleventh embodiment has substantially the same effect as the developing device 13I according to the tenth embodiment.

(Embodiment 12)
FIG. 102 is a cross-sectional view parallel to the rotation axis direction of the developing device according to the twelfth embodiment. A developing device 13K according to the twelfth embodiment will be described with reference to FIG.

  As shown in FIG. 102, the developing device 13K according to the twelfth embodiment is different from the developing device 13I according to the tenth embodiment in the shape and the second shape of the first rotating shaft 210K in the first developer conveying member 21K. The shape of the second rotating shaft 250K in the developer conveying member 22K is different. Other configurations are almost the same.

  The first developer conveying member 21K includes a first rotating shaft 210K and a first auger 220I. The first rotating shaft 210K includes a first eccentric part 213, a second eccentric part 214, a third eccentric part 215, a fourth eccentric part 216, and a fifth eccentric part 210K1. The first eccentric part 213, the second eccentric part 214, the third eccentric part 215, and the fourth eccentric part 216 have substantially the same configuration as that of the sixth embodiment. The fifth eccentric portion 210K1 has substantially the same configuration as the eccentric portion of the rotary shaft 210A according to the first embodiment.

  The second developer conveying member 22K includes a second rotating shaft 250K and a second auger 260. The second rotating shaft 250K has a first eccentric portion 250K1 and a second eccentric portion 250K2. The first eccentric portion 250K1 is configured in substantially the same manner as the eccentric portion of the rotary shaft 210A according to the second embodiment. Second eccentric portion 250K2 is configured in substantially the same manner as the eccentric portion of rotary shaft 210D according to the fifth embodiment.

  Even in such a case, the developing device 13J according to the eleventh embodiment has substantially the same effect as the developing device 13I according to the tenth embodiment.

(simulation result)
FIG. 103 is a diagram illustrating the amount of movement of the developer that moves in the plane direction perpendicular to the rotation axis in the simulation performed to verify the effect according to the embodiment. FIG. 104 is a diagram illustrating the amount of movement of the developer that moves in the circumferential direction in a simulation performed to verify the effect according to the embodiment. FIG. 105 is a diagram illustrating the amount of movement of the developer that moves in a direction parallel to the rotation axis in a simulation performed to verify the effect according to the embodiment. With reference to FIG. 103 to FIG. 105, a description will be given of a simulation result performed to verify the effect according to the embodiment.

  For the developing devices provided with the conveying members in Comparative Example 1, Comparative Example 2, Example 1, and Example 2, the amount of developer movement was simulated using CAE analysis. That is, in each of Comparative Example 1, Comparative Example 2, Example 1, and Example 2, how much each of the developer particles moved during a certain period of time was traced. The average of the movement amount in the range between 25% and 75% in the range from the minimum to the maximum is shown in FIGS.

  In the developing device in Comparative Example 1, the shape of the rotating shaft was a columnar shape, and the center of gravity in the cross-sectional shape of the rotating shaft perpendicular to the rotating shaft of the rotating shaft was matched with the rotating shaft of the rotating shaft. An auger was provided on the peripheral surface of the rotating shaft. The rotation center of the auger and the rotation axis of the rotation shaft were matched.

  In the developing device in Comparative Example 2, the conveying member has substantially the same configuration as that of the comparative example described above. That is, in addition to Comparative Example 1, a paddle projecting in the radial direction of the rotating shaft from the peripheral surface of the rotating shaft was provided.

  In the developing device in Example 1, the conveying member has substantially the same configuration as that of the first embodiment. Specifically, the rotating shaft includes an eccentric portion in which the center of gravity in the sectional shape of the rotating shaft perpendicular to the rotating shaft and the position of the rotating shaft are shifted, and the sectional shape of the rotating shaft in the eccentric portion is circular. .

  In the developing device in Example 2, the conveying member has substantially the same configuration as that of the first embodiment. Specifically, the rotating shaft includes an eccentric portion having a center of gravity having a cross-sectional shape orthogonal to the rotating shaft at a position shifted from the rotating shaft, and the cross-sectional shape of the rotating shaft in the eccentric portion is circular.

  In the developing device in Example 2, the conveying member has substantially the same configuration as that of the second embodiment. Specifically, the rotating shaft includes an eccentric portion having a center of gravity having a cross-sectional shape orthogonal to the rotating shaft at a position shifted from the rotating shaft, and the cross-sectional shape of the rotating shaft in the eccentric portion is an elliptical shape.

  FIG. 103 shows the amount of developer movement based on the moving force VR shown in FIG. The movement amount based on the moving force VR includes a vector that moves in a direction different from the direction away from the rotation axis of the rotation shaft and the direction used for the rotation axis. In this simulation, an absolute value is used as the movement amount. It represents as. FIG. 104 shows the amount of developer movement based on the moving force Vθ shown in FIG.

  As shown in FIGS. 103 and 104, in both Example 1 and Example 2, the amount of movement was larger than in Comparative Example 1 and Comparative Example 2.

  From these results, it was confirmed that the stirrability of the developer can be improved by shifting the center of gravity in the cross-sectional shape of the rotating shaft perpendicular to the rotating shaft and the position of the rotating shaft.

  In FIG. 105, the moving amount based on the moving force VZ shown in FIG. 19 is shown. In Example 1, although the movement amount was slightly lower than that in Comparative Example 1, an equivalent conveyance amount was obtained. In addition, the amount of movement in Example 1 was greater than that in Comparative Example 2. In Example 2, the amount of movement decreased compared to Comparative Example 1, but the amount of movement increased compared to Comparative Example 2.

  From these results, as in Example 1 and Example 2, the configuration in which the center of gravity in the cross-sectional shape of the rotating shaft perpendicular to the rotating shaft and the position of the rotating shaft are shifted is compared with Comparative Example 2. It can be said that the developer can be prevented from escaping from the front end side of the auger 220 to the outside of the auger, and a considerable amount of the developer can be pressed in the vertical direction by the helical surface of the auger. Thereby, it can be said that it was able to move to the arrow AR direction (refer FIG. 4) by the component of the longitudinal direction of the above-mentioned conveyance force V, and it was able to suppress the fall of conveyance property.

  In the above-described embodiment, when referring to the number, amount, and the like, the scope of the present invention is not necessarily limited to the number, amount, and the like unless otherwise specified. In the above-described embodiment, each component is not necessarily essential to the present invention unless otherwise specified. In addition, when there are a plurality of embodiments as described above, it is planned from the beginning to appropriately combine the features of each embodiment unless otherwise specified. For example, each of the developer conveying members according to the second to twelfth embodiments can be appropriately used for the developing device and the image forming apparatus according to the first embodiment.

  As described above, the embodiment invented this time is illustrative in all points and is not restrictive. The scope of the present invention is defined by the terms of the claims, and includes meanings equivalent to the terms of the claims and all modifications within the scope.

  1C, 1K, 1M, 1Y Image forming unit, 10 photoconductor, 11 charging device, 12 exposure device, 13, 13I, 13J, 13K developing device, 14 developing roller, 15C, 15K, 15M, 15Y toner bottle, 17 cleaning device 21, 21A, 21B, 21C, 21D, 21E, 21F, 21G, 21H, 21K, 21X First developer conveying member, 22, 22J, 22K Second developer conveying member, 30 intermediate transfer belt, 31 primary transfer roller , 33 Secondary transfer roller, 37 cassette, 38 driven roller, 39 drive roller, 40 timing roller, 41 transport path, 48 tray, 50 fixing device, 60 paper type detection unit, C1, C2, C3, C4, C5, C6 , C71, C72, C81, C82, CX center of gravity, 100 image forming apparatus , 101 control unit, 130 housing, 131 first storage unit, 132 second storage unit, 133 developing roller storage unit, 134 wall unit, 210, 210A, 210B, 210C, 210D, 210E, 210F, 210F1, 210G, 210H , 210X rotary shaft, 210F1, 213, 250J1, 250K1, 250F1 first eccentric part, 210F2, 210G2, 214, 250J2, 250K2 second eccentric part, 210G3, 215 third eccentric part, 210I, 210K first rotary shaft, 210K1 5th eccentric part, 211 1st surface, 212 2nd surface, 216 4th eccentric part, 217 Support shaft, 220, 220X auger, 220a Conveying surface, 220I 1st auger, 230 paddle, 250, 250J, 250K Second rotation Shaft, 260 2nd O , 300 drive mechanism 310 first gear portion 320 second gear portion, 400 bearing unit.

Claims (14)

A developer conveying member disposed in the developing device for conveying the developer,
A rotating shaft having a rotating shaft and rotatable about the rotating shaft;
An auger provided spirally on the peripheral surface of the rotating shaft, and transporting the developer by rotating;
The auger is configured such that when the rotary shaft rotates, each part constituting the auger draws a circular locus centering on the rotation center when viewed from the rotation axis direction.
The developer transport member, wherein the rotation shaft includes an eccentric portion having a center of gravity of a cross-sectional shape perpendicular to the rotation axis at a position shifted from the rotation axis at least at a part in the rotation axis direction.   The developer conveying member according to claim 1, wherein the cross-sectional shape in the eccentric portion is a circular shape, an elliptical shape, or an egg shape. The cross-sectional shape in the eccentric part has a first surface facing the front side in the rotational direction of the rotating shaft and a second surface facing the rear side in the rotational direction,
The developer conveying member according to claim 1, wherein the first surface has a curved shape that bulges in the rotation direction. The eccentric portion includes a first eccentric portion and a second eccentric portion arranged along the rotation axis direction,
The cross-sectional shape in the first eccentric portion is a circular shape, an elliptical shape, or an egg shape,
The cross-sectional shape of the second eccentric portion has a first surface facing the front side in the rotation direction of the rotating shaft and a second surface facing the rear side in the rotation direction,
The developer conveying member according to claim 1, wherein the first surface has a curved shape that bulges to the front side in the rotation direction.   The developer conveying member according to claim 1, wherein the cross-sectional shape of the eccentric portion is constant along the rotation axis direction.   4. The developer conveying member according to claim 1, wherein the eccentric portion has a shape in which the cross-sectional shape is continuously rotated around the rotation axis along the rotation axis direction. 5. The eccentric portion includes a first eccentric portion and a second eccentric portion that are adjacent to each other along the rotation axis direction,
The cross-sectional shape of each of the first eccentric portion and the second eccentric portion is constant along the rotation axis direction,
4. The developer conveyance according to claim 1, wherein the cross-sectional shape of the first eccentric portion matches a shape obtained by rotating the cross-sectional shape of the second eccentric portion around the rotation axis. 5. Element. The eccentric portion includes a first eccentric portion and a second eccentric portion arranged along the rotation axis direction,
The developer conveying member according to claim 1, wherein the cross-sectional shape of the first eccentric portion is different from the cross-sectional shape of the second eccentric portion. In the cross-sectional shape in the eccentric portion, when a straight line connecting the center of gravity and the rotation axis intersects the cross-sectional shape on the side where the center of gravity is located with respect to the rotation axis,
9. The developer transport according to claim 1, wherein the center of gravity of the cross-sectional shape is located between the intersection and the intermediate point of the rotation shaft and the rotation shaft in the cross-sectional shape. Element. The cross-sectional shape of the eccentric part includes a curved arc part and a connection part that connects both ends of the arc part,
When viewed from the direction of the rotation axis, the cross-sectional shape is parallel to a straight line connecting the center of the arc portion and the center of gravity, and is orthogonal to the first straight line and passes through the rotation axis. When the circular trajectory of the auger is partitioned by the second straight line passing through the rotating shaft, the connecting portion is located with respect to the second straight line with respect to the center of gravity of the cross-sectional shape in the eccentric portion. A side located on the side opposite to the side, and located on the rear side in the rotational direction with respect to the first straight line of the portion located on the side opposite to the side on which the connecting portion is located with respect to the second straight line, The developer conveying member according to claim 1. A developer conveying member disposed in the developing device for conveying the developer,
A rotating shaft having a rotating shaft and rotatable about the rotating shaft;
An auger provided spirally on the peripheral surface of the rotating shaft, and transporting the developer by rotating;
The auger is configured such that when the rotary shaft rotates, each part constituting the auger draws a circular locus centering on the rotation center when viewed from the rotation axis direction.
The rotating shaft includes a region where the center of gravity of the cross-sectional shape of the rotating shaft perpendicular to the rotating shaft coincides with the rotating shaft, and a region where the center of gravity of the cross-sectional shape is located away from the rotating shaft. Conveying member. A developer conveying member disposed in the developing device for conveying the developer,
A first rotating shaft and a second rotating shaft each having a rotating shaft and rotatable about each rotating shaft;
A first auger that is spirally provided on the circumferential surface of the first rotating shaft and conveys the developer by rotating;
A second auger provided spirally on the peripheral surface of the second rotating shaft and transporting the developer by rotating;
The first auger is configured such that each part of the first auger draws a circular trajectory centered on the rotation center when viewed from the direction of the rotation axis when the first rotation shaft rotates. And
The second auger is configured such that each of the parts constituting the first auger draws a circular trajectory centered on the rotation center when viewed from the direction of the rotation axis when the second rotation shaft rotates. And
The rotation axis of the first rotation shaft is opposed to and parallel to the rotation axis of the second rotation shaft;
At least one of the first rotating shaft and the second rotating shaft includes an eccentric portion having a center of gravity having a cross-sectional shape orthogonal to the rotating shaft at a position shifted from the rotating shaft at least at a part in the rotating shaft direction. Developer transport member.   A developing device comprising: the developer conveying member according to claim 1; and an accommodating portion that accommodates the developer conveying member. A developing device according to claim 13;
An image forming apparatus comprising: an image carrier that carries a toner image developed by the developing device.

Images