JP2018066770A - Developer agitating member and developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developer conveying member capable of improving agitating performance without lowering conveying properties of a developer.SOLUTION: A developer conveying member includes: a rotating shaft part 51; a spiral-shaped blades 52 provided on the surface of the shaft part 51; plate-shaped parts 53, 54 which are provided in the axial direction so as to couple between blades 52 and provided symmetrically to the shaft part 51. Then, in a cross-sectional shape of the shaft part 51 in a cross-section perpendicular to the axial direction, the length in a direction parallel to the inner side of the plate-shaped parts 53, 54 is longer than that in the direction perpendicular to the inner inside of the plate shaped parts 53, 54.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a developer stirring member and a developing device using the same.

  In recent years, there has been a demand for downsizing and cost reduction of an apparatus, as well as higher image forming speed and higher image quality. As the image forming speed increases, image defects such as image unevenness and fogging easily occur due to insufficient conveyance of developer and insufficient stirring. Further, as the apparatus is further downsized, the developer conveying member is also reduced, and insufficient conveyance of the developer is promoted, so that image defects are more likely to occur. Means for suppressing these image defects have been conventionally proposed.

  For example, Patent Document 1 proposes a developing device in which a sub flow path different from the main circulation path is provided, and a stirring screw having a high stirring ability and a low conveyance speed is provided in the sub flow path. And the thing which provided the spiral blade | wing inside the cylindrical member as said stirring screw is proposed. However, in the developing device having such a configuration, since it is necessary to provide a sub-flow path different from the main circulation path in order to increase the stirring ability, the apparatus becomes large.

  In Patent Document 2, a hollow spiral member, a pair of rib members that support the spiral member, a protruding member that extends along the outer wall portion of the rib member from a region where the spiral member and the rib member intersect, and There has been proposed a developer transport member that has a developer and can adjust the developer transport capability. However, in the developer conveying member having such a configuration, since there is no rotation shaft, the developer conveying property is lowered.

  Further, in Patent Document 3, each of the annular portions divided into a plurality in the circumferential direction is a wheel-like rotating body supported by a spoke-like support member with respect to the rotation shaft, and is novel from the replenishing device to the developing device. A replenishment control member that can change the toner replenishment state in the longitudinal direction when replenishing toner is disclosed. However, the replenishment control member disclosed in Patent Document 3 controls toner replenishment to the developing device, and does not take into consideration developer transportability and agitation.

JP 2005-352042 A JP 2013-246273 A JP 2008-276119 A

  An object of the present invention is to provide a developer conveying member capable of improving the agitating property without deteriorating the developer conveying property.

  Another object of the present invention is to provide a developing device that is small in size and capable of obtaining a high-quality image in which image defects such as density unevenness and fog are suppressed.

  The developer conveying member according to the present invention that achieves the above object is provided in the axial direction so as to connect the rotating shaft portion, the spiral blades provided on the surface of the shaft portion, and the blades. In a cross-section perpendicular to the axial direction, the cross-sectional shape of the shaft portion is parallel to the inner side of the plate-like portion from the length in the direction perpendicular to the inner side of the plate-like portion. The length of is a longer shape.

  According to this configuration, the developer can smoothly move between the shaft portion and the plate-like portion, and the moving speed of the developer in the axial direction does not decrease. This makes it possible to improve the stirring performance while maintaining the moving speed of the developer in the axial direction. Further, the stress applied to the developer by stirring can be suppressed. Furthermore, since the developer is moved in the rotation direction by the shaft portion, the stirring performance is improved.

  In the developer conveying member having the above-described configuration, the plate-like portion is provided so as to be symmetric with respect to the shaft portion.

  In the developer conveying member having the above-described configuration, the outer peripheral shape of the shaft portion facing the plate-like portion and the shape of the inner side of the plate-like portion substantially coincide with each other in a cross section perpendicular to the axial direction. Features. Here, it is preferable that the outer peripheral shape of the shaft portion is a convex curved surface shape, and the shape of the inner side of the plate-like portion is a concave curved surface shape.

  In the developer conveying member having the above-described configuration, the outer peripheral shape of the shaft portion and the shape of the inner side of the plate-like portion are linear.

  In the developer conveying member having the above-described configuration, the shape of the outer side of the plate-like portion is a curved surface, and the curvature of the curved surface is substantially the same as the curvature of the outer periphery of the blade.

  In the developer conveying member having the above-described configuration, the end of the plate-like portion on the front end side in the rotational direction has an acute angle shape in a cross section perpendicular to the axial direction.

  In the developer conveying member having the above-described configuration, the plate-like portion is provided so as to connect between the outer peripheral ends of the blades in the axial direction.

  In the developer conveying member having the above-described configuration, the plate-like portion is provided over the entire axial direction.

  In the developer conveying member having the above-described configuration, a plurality of the plate-like portions are provided at predetermined intervals in the axial direction.

  The developing device according to the present invention that achieves the above object includes a plurality of conveying members that convey the developer, and a circulation path that accommodates the plurality of conveying members and circulates the developer between the plurality of conveying members. A developing device that is disposed in the housing and has a developer carried on the surface thereof and is rotatable, and at least one of the plurality of transport members is any of the above It is comprised by the developer conveyance member of the above.

  In the developing device having the above-described configuration, at least one of the plurality of transport members other than the transport member closest to the developer carrier is configured by the developer transport member according to any one of the above. It is characterized by that.

  In the developing device configured as described above, the circulation path includes a first transport path in which the developer is transported in a predetermined direction, and the developer is transported in a direction opposite to the first transport path and the first transport path. A second conveyance path that extends in parallel adjacent to the conveyance path, a partition member that partitions between the first conveyance path and the second conveyance path, and the first conveyance path and the second conveyance. And a communicating portion in which the partition member is opened so that the developer circulates in the path, and a conveying member configured by the developer conveying member according to any one of the above, a portion facing the communicating portion The plate-like portion is not provided, or the circumferential length of the plate-like portion of the portion facing the communication portion is the shortest compared to the circumferential length of the other portions of the plate-like portion. It is characterized by.

  Further, in the developing device having the above-described configuration, the shaft portion of the portion of the transport member configured by the developer transport member according to any one of the above, facing the communication portion and from which the developer is carried in from the communication portion The cross-sectional shape is a round shape.

  The developing device having the above-described configuration further includes a replenishing port for replenishing toner or developer, and a portion facing the replenishing port in the transporting member configured by the developer transporting member according to any one of the above. Is not provided with the plate-like portion, or the circumferential length of the plate-like portion of the portion facing the replenishing port is the shortest in comparison with the circumferential length of the other portion. Features.

  According to the developer transport member of the present invention, it is possible to improve the agitation without reducing the transportability of the developer.

  Further, according to the developing device of the present invention, it is possible to obtain a high-quality image that is small in size and suppresses image defects such as density unevenness and fogging.

1 is a schematic diagram illustrating an example of an image forming apparatus. It is a schematic diagram which shows an example of a developing device. FIG. 10 is a schematic cross-sectional view and a front view of a conventional developer conveying member perpendicular to the axial direction. FIG. 10 is a schematic sectional view and a front view of another conventional developer conveying member perpendicular to the axial direction. FIG. 4 is a perspective view illustrating an example of a developer conveying member according to the present invention. FIG. 6 is a cross-sectional view perpendicular to the axial direction of the developer conveying member in FIG. 5. FIG. 6 is a cross-sectional view perpendicular to the axial direction of a conventional developer conveying member in which a shaft has a round cross-sectional shape. FIG. 8 is an explanatory diagram illustrating the movement of the developer in the conventional developer transport member of FIG. 7. It is explanatory drawing which shows the motion of the developer in the developer conveyance member which concerns on this invention. FIG. 6 is a cross-sectional view perpendicular to the axial direction showing another example of the developer conveying member according to the present invention. FIG. 10 is a cross-sectional view perpendicular to the axial direction showing still another example of the developer conveying member according to the present invention. FIG. 10 is a cross-sectional view perpendicular to the axial direction showing still another embodiment of a developer conveying member according to the present invention. It is a front view explaining the installation state of the plate-shaped member in the axial direction of the developer conveyance member which concerns on this invention. 1 is a schematic diagram illustrating an embodiment of a developing device according to the present invention. It is a schematic diagram which shows other embodiment of the developing device which concerns on this invention. It is a schematic diagram which shows other embodiment of the developing device which concerns on this invention. It is a schematic diagram which shows other embodiment of the developing device which concerns on this invention. It is a schematic diagram which shows other embodiment of the developing device which concerns on this invention.

  Hereinafter, the developer conveying member and the developing device according to the present invention will be described with reference to the drawings. However, the present invention is not limited to these embodiments.

  FIG. 1 is a schematic view showing an example of an image forming apparatus equipped with a developing device according to the present invention. The image forming apparatus in FIG. 1 is a tandem digital color printer (hereinafter, simply referred to as “printer”). Of course, in addition to a printer, the present invention can also be applied to a copying machine having a scanner, a facsimile, or a multi-function machine having these functions combined. In the following, when it is necessary to clarify whether the device or member to be described is yellow (Y), magenta (M), cyan (C), or black (Bk), The description will be made by adding the characters “(Y)”, “(M)”, “(C)”, and “(Bk)” to the reference numerals, and otherwise omitting these characters.

  The printer 1 includes an intermediate transfer belt 11 at substantially the center of the inside thereof. The intermediate transfer belt 11 is wound around the outer periphery of the roller 12, the tension roller 13, and the guide rollers 14 and 15, and is driven to rotate counterclockwise. The tension roller 13 is slidably attached to the outside and is urged by the pressing spring S from the inside to the outside of the intermediate transfer belt 11. Thus, the intermediate transfer belt 11 is always in a tensioned state.

  Below the lower horizontal portion of the intermediate transfer belt 11, four image forming portions 2Y, 2M, 2C, and 2Bk corresponding to yellow (Y), magenta (M), cyan (C), and black (Bk) colors, respectively. Are arranged in this order along the intermediate transfer belt 11. Each of the image forming units 2Y, 2M, 2C, 2Bk has a photosensitive drum (electrostatic latent image carrier) 21Y, 21M, 21C, 21Bk, respectively. Around each of the photoconductive drums 21Y, 21M, 21C, and 21Bk, the chargers 22Y, 22M, 22C, and 22Bk, the print head portions 23Y, 23M, 23C, and 23Bk, and the developing device 24Y are sequentially arranged along the rotation direction. , 24M, 24C, 24Bk and cleaners (cleaning means) 25Y, 25M, 25C, 25Bk are arranged, respectively. The print head portions 23Y, 23M, 23C, and 23Bk are composed of a large number of LEDs arranged in the main scanning direction parallel to the axial direction of the photosensitive drum.

  Further, primary transfer rollers 30Y, 30M, 30C, and 30Bk are provided at positions facing the respective photosensitive drums 21Y, 21M, 21C, and 21Bk with the intermediate transfer belt 11 interposed therebetween. A secondary transfer roller 16 is pressed against the portion of the intermediate transfer belt 11 supported by the roller 12. A nip portion between the secondary transfer roller 16 and the intermediate transfer belt 11 becomes a secondary transfer region 17. The toner image formed on the intermediate transfer belt 11 in the secondary transfer region 17 is transferred onto the conveyed paper P.

  A paper feed cassette 91 is detachably disposed at the bottom of the printer 1. The sheets P stacked and housed in the sheet feeding cassette 91 are pulled out one by one from the uppermost one by the rotation of the sheet feeding roller 92 and sent out to the transport path 93. The conveyance path 93 extends from the paper feed cassette 91 to the paper discharge tray 98 through the nip portion of the timing roller pair 94, the secondary transfer region 17, and the fixing unit 95. The paper P sent out from the paper feed cassette 91 is conveyed to the timing roller pair 94 and is sent out to the secondary transfer area 17 at a predetermined timing.

  The fixing unit 95 has a hollow cylindrical shape, and includes a fixing roller 96 having a halogen heater H therein, and a pressure roller 97 that is pressed against the fixing roller 96 and rotates. A nip portion between the fixing roller 96 and the pressure roller 97 through which the sheet P on which the toner image is secondarily transferred passes is a fixing region.

  A schematic operation of the printer 1 having such a configuration will be described. First, in the full color mode for outputting a color image, when an image signal is input from an external device (for example, a personal computer) to an image signal processing unit (not shown) of the printer 1, the image signal processing unit converts the image signal to yellow, A digital image signal color-converted to cyan, magenta, and black is created, and this signal is transmitted to the LED drive circuit for the print head. This drive circuit performs exposure by causing the print head units 23Y, 23M, 23C, and 23Bk of the image forming units 2Y, 2M, 2C, and 2Bk to emit light based on the input digital signals. This exposure is performed with a time difference in the order of the print head units 23Y, 23M, 23C, and 23Bk. Thereby, electrostatic latent images for the respective colors are formed on the surfaces of the respective photosensitive drums 21Y, 21M, 21C, and 21Bk.

  The electrostatic latent images formed on the photosensitive drums 21Y, 21M, 21C, and 21Bk are respectively developed by the developing devices 24Y, 24M, 24C, and 24Bk to become toner images of the respective colors. Then, the toner images of the respective colors are sequentially primary-transferred and superimposed on the intermediate transfer belt 11 that rotates counterclockwise in the figure by the action of the primary transfer rollers 30Y, 30M, 30C, and 30Bk.

  The toner image formed on the intermediate transfer belt 11 in this way reaches the secondary transfer region 17 as the intermediate transfer belt 11 moves. On the other hand, the paper P sent out from the paper feed cassette 91 to the transport path 93 is transported to the secondary transfer region 17 by the timing roller pair 94 at the timing when the toner image reaches the secondary transfer region 17. A voltage having a polarity opposite to the charging polarity of the toner is applied to the secondary transfer roller 16. As a result, in the secondary transfer region 17, the superimposed color toner images are secondarily transferred collectively from the intermediate transfer belt 11 to the paper P. The toner remaining on the intermediate transfer belt 11 after the secondary transfer is collected by a belt cleaner (not shown).

  The sheet P onto which the toner image has been secondarily transferred is sent to the fixing unit 95 through the conveyance path 93, where the toner image is fixed on the sheet P by passing through the fixing region. Then, the paper P is discharged to the paper discharge tray 98.

  Next, the developing device 24 mounted on the printer 1 in FIG. 1 will be described. FIG. 2 is a cross-sectional view of the developing device 24Bk. The developing device 24Bk in FIG. 2 develops the electrostatic latent image on the photosensitive drum 21Bk using a two-component developer D having a carrier made of magnetic particles and toner. The developing device 24Bk includes a housing 61, a developing roller (developer carrying member) 4 that includes a plurality of magnetic poles and is rotatably supported by the housing 61, and the rotation axis and the rotation axis of the developing roller 4 are substantially parallel to each other. Two developer conveying members 5a and 5b that are rotatably supported by the housing 61 at an interval are provided. The housing 61 is provided between the first conveyance path 64a and the second conveyance path 64b, and the first conveyance path 64a and the second conveyance path 64b, which respectively accommodate the developer conveyance member 5a and the developer conveyance member 5b. A partition plate 62 for partitioning and connecting portions 65a and 65b (shown in FIG. 14) formed at both ends in the longitudinal direction of the partition plate 62 are provided. The first conveyance path 64a, the second conveyance path 64b, the partition plate 62, and the communication portions 65a and 65b constitute a circulation path T (shown in FIG. 14) for the developer D.

  The two developer conveying members 5a and 5b are rotated in opposite directions by a drive mechanism (not shown). The developer D is conveyed while being agitated in the direction toward the back of the sheet by rotating the developer conveying member 5a and toward the front of the sheet by rotating the developer conveying member 5b. Then, at both end portions of the developer transport members 5a and 5b, the communication portions 65a and 65b (shown in FIG. 14) formed at both end portions of the partition plate 62 are passed through from one developer transport member to the other developer. The developer moves to the conveying member. As a result, the developer D is constantly circulated through the housing 61 and stirred. The toner is charged to a predetermined value by circulating in the housing 61 while being stirred. The circulating conveyance of the developer D by the two developer conveying members 5a and 5b will be described in detail later.

  The developing roller 4 that carries the developer D on the surface and rotates and conveys it to the developing nip portion is composed of a magnet roller (magnetic field generating means) and a cylindrical developing sleeve that houses the magnet roller, and the magnet roller is fixed. At the same time, the developing sleeve rotates relative to the magnet roller. The developing sleeve is made of a nonmagnetic material such as aluminum.

  The developing roller 4 receives the developer D from the developer conveying member 5a, conveys the developer D regulated to a desired amount by the regulating member 63 to the developing nip portion, and the latent image formed on the photosensitive drum 21Bk. Is visualized with toner. At this time, in the development nip portion, in order to cause the toner to fly to the photosensitive drum 21Bk, a rectangular wave or a sine wave having a DC component of −200 V to 900 V as a developing bias and an AC component of frequency = 3 to 7 kHz and Vpp = 1 to 3 kVpp. Is applied between the developing roller 4 and the photosensitive drum 21Bk.

  FIG. 3A shows a schematic cross-sectional view of a conventional developer conveying member perpendicular to the axial direction, and FIG. 3B shows a front view. The conventional developer conveying member has a configuration in which a spiral blade 52 is wound around a round shaft portion 511, and both ends of the shaft portion 511 are rotatably supported by a housing by bearings. By inputting driving from either one end of the shaft portion 511, the developer transport member rotates, and the developer D can be fed in the winding direction of the spiral blade 52. The conveyance of the developer D in the axial direction by the spiral blade 52 has been conventionally used in many apparatuses.

  By the way, the occurrence of image noise such as density unevenness and fogging is one of the main causes of insufficient stirring of the developer. In recent years, there has been a strong market demand for high image quality, while the miniaturization of the apparatus has progressed and the speed has increased. There is an increasing need to stir the developer more reliably.

  FIG. 4A shows a schematic cross-sectional view of another conventional developer conveying member perpendicular to the axial direction, and FIG. 4B shows a front view. The developer transport member shown in FIG. 4 includes a round shaft portion 511 and a spiral blade 52 as in the developer transport member of FIG. It is provided only on the outer sides of both axial ends, and the shaft portion 511 does not exist in the central portion in the axial direction. That is, the developer conveying member in this figure is in a state where a space is formed in a portion where the shaft portion 511 is provided in the conventional developer conveying member. Further, plate-like portions 53 and 54 extending in the axial direction are provided on the outer peripheral surface of the spiral blade 52. Since the developer is moved so as to stir in the rotation direction by the plate-like portions 53 and 54, the developer can be well mixed with the surrounding developer.

  However, since the shaft portion 511 is eliminated at the central portion in the axial direction, the developer conveyed in the axial direction by the spiral blade 52 escapes to the space formed at the center of the shaft, and in the axial direction of the developer. This will reduce the transportability.

  FIG. 5 is a perspective view showing an example of the developer conveying member according to the present invention. FIG. 6 is a cross-sectional view perpendicular to the axial direction. The developer conveying member 5b of the present invention shown in these drawings is provided with spiral blades 52 around a shaft portion 51 having an elliptical cross section, and is connected so that the outer peripheral ends of the blades 52 are connected in the axial direction. The shaped portions 53 and 54 are provided over the entire axial direction of the developer conveying member 5b. The shaft portion 51 and the blade 52 may be attached after being formed separately or may be integrally formed. In addition, the blade 52 and the plate-like portions 53 and 54 may be attached after being formed separately, or may be integrally formed. In the conventional developer conveying member shown in FIG. 4, the shaft portion does not exist in the central portion in the axial direction, but in the developer conveying member of the present invention, the shaft portion 51 exists in the entire axial direction. As a result, the transport amount of the developer in the axial direction does not decrease. Furthermore, since the cross-sectional shape of the shaft portion 51 is elliptical, as shown in FIG. 6, the developer can be transported in the radial direction and the rotation direction by the shaft portion 51. As a result, a force for transporting the developer is generated in the three directions of the axial direction, the rotation direction, and the radial direction, and the stirring ability can be improved without reducing the developer transport capability. .

  FIG. 7 shows the case of a conventional developer conveying member in which the shaft portion 511 has a round cross section. FIG. 8 shows the developer conveyed between the shaft portion 511 having a round cross section and the plate portion 53. The movement of D is shown. As shown in FIG. 8, in the case of the shaft portion 511 having a round cross section, the interval between the shaft portion 511 and the plate portion 53 is abrupt before and after the developer D passes between the shaft portion 511 and the plate portion 53. Becomes narrower. For this reason, the developer D is stagnated in the portion where the two members 511 and 53 are closest to each other, and the conveying ability in the axial direction is reduced. In addition, the developer D is stressed in the narrow passage portion, which is one of the factors that shorten the life of the developer D.

  On the other hand, as shown in FIG. 9, when the cross-sectional shape of the shaft portion 51 is elliptical, the shaft portion 51 and the plate-like portion 53 are before and after the developer D passes between the shaft portion 51 and the plate-like portion 53. The interval between and becomes gradually narrower. As a result, even when the two members 51 and 53 are closest, the developer D can move smoothly without stagnation, and the transportability of the developer D in the axial direction does not deteriorate. Further, the developer D is not excessively stressed in the narrow passage width portion, and the life of the developer D is not affected.

  In addition, although the case where the cross-sectional shape of the axial part 51 was an ellipse was demonstrated so far, the axial part 51 used by this invention is not limited to this, The cross-sectional shape of the axial part 51 is a plate-shaped part. If the length in the direction substantially parallel to the inner side of the plate-like portion 53 (y direction in FIG. 9) is longer than the length in the direction substantially perpendicular to the inner side of 53 (x direction in FIG. 9). For example, the same effect can be obtained even when the shaft 51a has a rectangular cross section as shown in FIG.

  In the developer conveying member shown in FIG. 10, the shaft portion 51a and the plate-like portions 53 and 54 each having a rectangular cross-section have a predetermined distance between the long side of the shaft portion 51a and the long sides of the plate-like portions 53 and 54. They are arranged so as to be parallel to each other. The shape of the inner side of the plate-like portions 53 and 54 and the outer peripheral shape of the shaft portion 51a facing the plate-like portions 53 and 54 are both linearly matched. Two plate-like portions 53 and 54 are provided symmetrically with respect to the shaft portion 51a. The length of the two plate-like portions 53 and 54 in the axial direction may be the length of the entire developer conveying member in the axial direction, or may be shorter than the entire length of the axial direction and predetermined in the axial direction. A plurality may be provided at intervals. With the developer transport member having such a configuration, the distance between the shaft portion 51a and the plate-like portions 53, 54 is approximately before and after the developer passes between the shaft portion 51a and the plate-like portions 53, 54. Accordingly, the developer can smoothly move between the shaft portion 51a and the plate-like portions 53 and 54 without stagnation, and the transportability of the developer in the axial direction does not deteriorate. Further, excessive stress is not applied to the developer, and the shaft portion 51a and the plate-like portions 53 and 54 do not affect the life of the developer.

  From the viewpoint of smoothly moving the developer between the shaft portion 51 and the plate-like portions 53, 54 before and after the developer passes between the shaft portion 51 and the plate-like portions 53, 54, What is necessary is just to make the space | interval of the axial part 51 and the plate-shaped parts 53 and 54 substantially equal. For example, as shown in FIG. 11, in the case of the shaft portion 51 having an elliptical cross-sectional shape, the concave curved surface shape is formed so that the shape of the inner side of the plate-like portions 53a and 54a matches the convex curved shape of the shaft portion 51 And Thereby, the space | interval of the axial part 51 and plate-shaped part 53a, 54a becomes substantially the same, and it becomes possible to move a developer smoothly between the shaft part 51 and plate-shaped part 53a, 54a, without stagnation. .

  FIG. 12 is a cross-sectional view perpendicular to the axial direction showing another embodiment of the developer conveying member according to the present invention. In the developer conveying member shown in this figure, similarly to the developer conveying member shown in FIG. 11, the cross-sectional shape of the shaft portion 51 is elliptical, and the shape of the inner sides of the plate-like portions 53 b and 54 b is the shape of the shaft portion 51. The concave curved surface shape coincides with the convex curved surface shape, and the outer sides of the plate-like portions 53b and 54b are convex curved surfaces, and the curvature thereof is substantially the same as the curvature of the outer periphery of the spiral blade 52. . By matching the shapes of the inner sides of the plate-like portions 53b and 54b with the outer peripheral shape of the shaft portion 51, the distance between the shaft portion 51 and the plate-like portions 53a and 54a can be made as in the developer conveying member of FIG. It becomes substantially the same, and the developer can smoothly move between the shaft portion 51 and the plate-like portions 53a and 54a without stagnation. Further, the outer sides of the plate-like portions 53b and 54b are convex curved surfaces, and the curvature thereof is substantially the same as the curvature of the outer periphery of the spiral blade 52, so that the plate-like portions 53b and 54b and the developer during rotation The contact resistance is reduced and the rotational torque of the developer conveying member is reduced. In addition, since the ends of the plate-like portions 53b and 54b on the front end side in the rotation direction have an acute-angled shape, the force that the tips of the plate-like portions 53b and 54b move the developer toward the outside of the blade 52 is weakened. Conversely, the force for scooping up the developer present outside the blade 52 toward the inside of the blade 52 is increased, and the agitation of the developer is further enhanced. In the embodiment described so far, the end of the plate-like portion on the front end side in the rotation direction may of course have an acute angle.

  FIG. 13 is a front view for explaining an installation state of the plate-like member 53 in the axial direction of the developer conveying member according to the present invention. The developer conveying member in FIG. 13A is obtained by installing the plate-like member 53 over the entire area in the axial direction, and the developer is axially, rotationally, and radially in the entire axial direction of the developer conveying member. Therefore, high agitation can be obtained. Further, the developer conveying member shown in FIG. 13B has a plurality of plate-like members 53 provided at predetermined intervals in the axial direction, and has a strong and weak movement of the developer in the axial direction of the developer conveying member. It can be mixed well with the surrounding developer.

(Developer)
The developing device according to the present invention will be described below. FIG. 14 shows a view of the inside of the developing device as seen from above. In FIG. 14, the housing 61 includes a circulation path T that rotatably supports the developing roller 4 and circulates the developer. The circulation path T is between the first transport path 64a, the second transport path 64b extending in parallel and adjacent to the first transport path 64a, and the first transport path 64a and the second transport path 64b. And a communication portion 65a, 65b opened at both ends in the longitudinal direction of the partition plate 62. The developer conveying member 5 a is accommodated in the first conveying path 64 a and is rotatably supported by the housing 61. The developer conveying member 5b is accommodated in the second conveying path 64b and is rotatably supported by the housing 61.

  The developer in the housing 61 is conveyed from the left to the right in FIG. 14 by the developer conveying member 5a, moves to the developer conveying member 5b via the communication portion 65a provided in the partition plate 62, and conveys the developer. It is conveyed from right to left by the member 5b. Then, the developer moves again to the developer transport member 5 a via the communication portion 65 b provided in the partition plate 62 and circulates in the housing 61. As described above, the toner in the developer is charged to a predetermined value while being circulated and conveyed through the housing 61. Further, the developer is supplied to the surface of the developing roller 4 from the developer conveying member 5a while being conveyed by the developer conveying member 5a.

  In the developing device having such a configuration, a conventionally known transport member, here, a transport member having a structure in which a spiral blade is provided on the surface of the shaft portion is used as the developer transport member 5a, and the developer transport member 5b is used as the developer transport member 5b. The developer conveying member of the invention is used. As described above, by using the developer conveying member of the present invention, it is possible to improve the agitation property without reducing the developer conveying property. On the other hand, the developer conveying member 5a provided adjacent to the developing roller 4 is required to play a role of supplying the developer to the developing roller 4 in addition to the role of stirring and conveying the developer. When the plate-like portion is provided so as to connect the spiral blades like the developer conveying member of the present invention, it is difficult to smoothly supply the developer to the developing roller 4. Therefore, it is recommended to use a conventionally known conveying member as the developer conveying member 5a and use the developer conveying member of the present invention as the developer conveying member 5b. In the developer conveying member 5 b shown in FIG. 14, the plate-like portion 54 is at a position that exactly overlaps the plate-like portion 53.

  Further, in the developing device shown in FIG. 14, the plate-like portion 53 (54) is not provided in a portion of the developer conveying member 5b facing the communication portions 65a and 65b. When the plate-like portion 53 (54) is provided, the developer movement (stirability) in the developer conveying member 5b is improved, but the force for moving the developer from the inside to the outside of the developer conveying member 5b. Becomes weaker. Therefore, by not providing the plate-like portions 53 and 54 at the portions facing the communication portions 65a and 65b, it is possible to smoothly transfer the developer between the developer conveying members in the communication portions 65a and 65b.

  Alternatively, as shown in FIG. 15, the circumferential lengths of the portions 531 (541) of the plate-like portions 53 and 54 facing the communication portions 65a and 65b in the developer conveying member 5b are set to the plate-like portions 53 and 54, respectively. You may make it become shortest compared with the length of the circumferential direction of other parts. Even with such a structure, the developer can be smoothly transferred between the developer conveying members in the communication portions 65a and 65b.

  Furthermore, in addition to the configuration of the developing device of FIGS. 14 and 15, a cross-sectional shape perpendicular to the axial direction of the shaft portion of the developer conveying member 5 b facing the communication portion 65 a may be round. The communication portion 65a is an area where the developer is transferred from the developer conveying member 5a to the developer conveying member 5b. By making the cross-sectional shape of the shaft portion 51 of the developer conveying member 5b in this area round, The force for moving the developer from the inside to the outside of the developer conveying member 5b by the portion 51 becomes weak, so that the developer can be smoothly transferred from the developer conveying member 5a to the developer conveying member 5b in the communication portion 65a. Become.

  16 to 18 are views of the inside of the developing device provided with the supply port 66 as seen from above. The basic configuration of this embodiment is the same as that of the above-described embodiment. Therefore, the same components as those in the previous embodiment are denoted by the same name and the same reference numerals as those in the previous embodiment, and detailed description thereof will be given. May be omitted.

  In the developing device shown in FIGS. 16 to 18, the second transport path 64 b is expanded upstream in the developer transport direction, and a replenishing port 66 for replenishing toner to the expanded portion (indicated by a broken line in FIGS. 16 to 18). (Shown) is formed. Since the toner in the developing device is consumed by toner image formation, when the toner density in the developing device decreases, the toner is replenished to the developing device via a replenishing port 66 from a toner hopper or a toner bottle (not shown). The toner supplied to the developing device needs to be taken in faster.

  Therefore, in the developing device shown in FIG. 16, the plate-like portion 53 (54) is not provided in the portion of the developer conveying member 5b that faces the supply port 66. This is because if the plate-like portion 53 (54) is provided in a portion facing the replenishing port 66, the toner replenished from the replenishing port 66 is not easily taken into the developer conveying member 5b. The toner replenished into the developing device from the replenishing port 66 is agitated and conveyed by the developer conveying member 5b to the communicating portion 65a, where it merges with the existing developer and is agitated and mixed, and the developer as described above. It is circulated and conveyed through the circulation path T by the conveying members 5a and 5b. During this time, the toner is charged to a predetermined value.

  In the developing device shown in FIG. 17, the second plate-like portion 532 (542) is provided in a portion of the developer conveying member 5b that faces the replenishing port 66. The second plate-like portion 532 (542) is circumferential. Is designed to be shorter than the circumferential length of the plate-like portions 53 and 54. With such a configuration, the toner replenished from the replenishing port 66 is smoothly taken into the developer conveying member 5b.

  Further, in the developing device shown in FIG. 18, a plurality of third plate-like portions 533 (543) are provided at predetermined intervals in a portion facing the supply port 66 in the developer conveying member 5b. The third plate-like portion 533 (543) has a circumferential length shorter than the circumferential length of the plate-like portions 53, 54, and each axial length is the second plate-like portion 532 (542). Designed to be shorter. Even with such a configuration, the toner replenished from the replenishing port 66 is smoothly taken into the developer conveying member 5b.

  In the embodiment shown in FIGS. 16 to 18, the toner is supplied from the supply port 66. However, when the developing device shown in these drawings is a so-called trickle type developing device, the developer is supplied from the supply port 66. It may be configured to replenish the developing device.

  The developer conveying member and the developing device of the present invention can be used in image forming apparatuses such as monochrome and color copying machines, printers, facsimiles, and multi-functional machines having a plurality of these functions.

  When the developing device has three or more transport members that transport the developer, the developer transport member of the present invention is preferably used as a transport member other than the transport member closest to the developing roller.

  According to the developer conveying member of the present invention, the stirring property can be improved without reducing the developer conveying property, which is useful.

1 Printer (image forming device)
4 Development roller (developer carrier)
D Developer T Circulation Path 5a Developer Conveying Member 5b Developer Conveying Member 24Bk Developing Device 51 Shaft 52 Blade 53, 54 Plate 531, 541 Plate 532, 542 Second Plate 533, 543 Third Plate Shaped part 61 Housing 62 Partition member 64a 1st conveyance path 64b 2nd conveyance path 65a, 65b Communication part 66 Supply port

Claims (15)

A conveying member for conveying the developer,
A rotating shaft,
A spiral blade provided on the surface of the shaft,
A plate-like portion provided in the axial direction so as to connect the blades,
In the cross section perpendicular to the axial direction,
The cross-sectional shape of the shaft portion is such that the length in the direction substantially parallel to the inner side of the plate-like part is longer than the length in the direction substantially perpendicular to the inner side of the plate-like part. Developer transport member.   The developer conveying member according to claim 1, wherein the two plate-like portions are provided so as to be symmetrical with respect to the shaft portion. In the cross section perpendicular to the axial direction,
The developer conveying member according to claim 1 or 2, wherein an outer peripheral shape of the shaft portion facing the plate-like portion and an inner side shape of the plate-like portion substantially coincide with each other.   The developer conveying member according to claim 3, wherein an outer peripheral shape of the shaft portion is a convex curved surface shape, and a shape of an inner side of the plate-like portion is a concave curved surface shape.   The developer conveying member according to claim 3, wherein the outer peripheral shape of the shaft portion and the shape of the inner side of the plate-like portion are linear.   The developer conveying member according to claim 1, wherein the shape of the outer side of the plate-like portion is a curved surface, and the curvature of the curved surface is substantially the same as the curvature of the outer periphery of the blade. In the cross section perpendicular to the axial direction,
The developer conveying member according to claim 1, wherein an end of the plate-like portion on the front side in the rotation direction has an acute-angle shape.   The developer conveying member according to claim 1, wherein the plate-like portion is provided so as to connect between the outer peripheral ends of the blades in the axial direction.   The developer conveying member according to claim 1, wherein the plate-like portion is provided over the entire axial direction.   The developer conveying member according to claim 1, wherein a plurality of the plate-like portions are provided at predetermined intervals in the axial direction. A plurality of conveying members for conveying the developer;
A housing in which a plurality of conveying members are accommodated and a circulation path for circulating the developer between the plurality of conveying members is formed;
A developer carrying member disposed in the housing and carrying a developer on a surface and being rotatable;
In a developing device comprising:
The developing device according to claim 1, wherein at least one of the plurality of transport members includes the developer transport member according to claim 1.   The developer transport member according to any one of claims 1 to 10, wherein at least one of the transport members other than the transport member closest to the developer carrier among the plurality of transport members is configured by the developer transport member according to any one of claims 1 to 10. Development device. The circuit is
A first conveyance path through which the developer is conveyed in a predetermined direction;
A second transport path in which the developer is transported in a direction opposite to the first transport path and extends parallel to and adjacent to the first transport path;
A partition member that partitions between the first transport path and the second transport path;
A communicating portion in which the partition member is opened so that the developer circulates in the first conveyance path and the second conveyance path;
With
The conveyance member comprised by the developer conveyance member in any one of Claims 1-10 WHEREIN: The said plate-shaped part is not provided in the part facing the said communication part, or it opposes the said communication part. The developing device according to claim 11 or 12, wherein a length in a circumferential direction of the plate-like portion of the portion is the shortest in comparison with a length in a circumferential direction of another portion of the plate-like portion.   The cross-sectional shape of the shaft portion of the conveying member constituted by the developer conveying member according to any one of claims 1 to 10 that faces the communicating portion and into which the developer is carried from the communicating portion is round. The developing device according to claim 13. A replenishing port for replenishing toner or developer;
The conveyance member comprised by the developer conveyance member in any one of Claims 1-10 WHEREIN: The said plate-shaped part is not provided in the part facing the said supply port, or it opposes the said supply port. The developing device according to claim 11 or 12, wherein the circumferential length of the plate-like portion of the portion is the shortest compared to the circumferential length of the other portion.