JP2019049732A - Stirring and conveying member, developing device, and image forming apparatus - Google Patents

Abstract

To provide a stirring and conveying member that prevents adhesion and build-up of developer, a developing device using the same, and an image forming apparatus.SOLUTION: A spiral blade 42b1 and a spiral blade 42b2 of a developer stirring and conveying member 42 is formed such that the length of a bottom face of a blade BR in contact with a shaft 42a in the direction of the shaft 42a is continuously increased and decreased. The width H1 and the width H2 of a first area R1 and a second area R2 as inclined parts are the same or different, that is, have the relationship of H1≥H2. A developer D flowing through a portion held between the first areas R1 and made into a narrow channel is divided into a developer D1 and a developer D2 and turned into turbulent flows. The developer D1 is separated from the blade BR and thereby conveyed in one period delay, and the developer D2 is separated from the blade BR and mixed with the developer D1 separated from the blade BR one period earlier.SELECTED DRAWING: Figure 4

Description

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

In an image forming apparatus such as a copying machine or a printer, a developing device is used to develop an electrostatic latent image formed on a photosensitive member. In this developing device, a developing roll is provided opposite to the photosensitive member, and, for example, a two-component developer consisting of a magnetic carrier and a toner mainly composed of a resin is stirred by a developer stirring and conveying member to develop The developer is fed to the developing roll from the agent feeding and conveying member.

Among such developer agitating and conveying members, there are some which are constituted by a plurality of spiral blades provided with a plurality of spiral blades on the surface of a rotating shaft. In the developing device and the image forming apparatus, a developer stirring and conveying member having such a plurality of spiral blades is used to cope with axial conveyance, stirring and the like of the developer (see Patent Document 1). .

JP, 2010-256429, A

In the stirring of the developer by the stirring and conveying member having a large number of spiral blades, the stirring property, the dispersibility, and the like are not sufficient, and the fixing, retention, and the like of the developer may occur.

An object of the present invention is to provide a stirring and conveying member that prevents the developer from sticking and staying, a developing device using the same, and an image forming apparatus.

The stirring and conveying member according to claim 1 includes a spiral blade formed to extend helically around a rotation axis, a discontinuous portion provided such that the spiral blade is discontinuous, and the spiral blade. And a portion that becomes wider toward the discontinuity.

The invention according to claim 2 is characterized in that, in the stirring and conveying member according to claim 1, the axial width of the bottom surface of the spiral blade is changed, so that the space between the spiral blades is directed to the discontinuous portion. It is characterized by becoming wide.
The invention according to claim 3 is characterized in that, in the stirring and conveying member according to claim 1 or 2, the inclination of the side surface of the spiral blade is changed, and the space between the spiral blades becomes wider as it goes to the discontinuous portion. It is characterized by becoming.
The invention according to claim 4 is characterized in that, in the stirring and conveying member according to any one of claims 1 to 3, the spiral blade has different phases around the rotation axis at the discontinuous portion.
The stirring and conveying member according to claim 5 is a first and a second flow path which is sandwiched by a spiral blade which is formed to extend helically around the rotation axis and which is adjacent in the axial direction of the rotation axis;
And a connection portion to which the first flow path and the second flow path are connected,
The width of the first flow path or the second flow path becomes wider as it goes to the connection portion.
The invention according to claim 6 is characterized in that, in the stirring and conveying member according to claim 5, the first flow passage or the second flow passage changes the axial width of the bottom surface of the spiral blade. It becomes characterized by becoming wide as it goes to the said connection part.
The invention according to claim 7 is characterized in that, in the stirring and conveying member according to claim 5 or 6, the first channel or the second channel changes the inclination of the side surface of the spiral blade. It is characterized by becoming wide as it goes to a connection part.
The invention according to claim 8 is characterized in that, in the stirring and conveying member according to any one of claims 5 to 7, the spiral blade has different phases around the rotation axis at the connection portion.
The invention according to claim 9 is characterized in that, in the stirring and conveying member according to any one of claims 5 to 8, the spiral blade has a portion overlapping in the circumferential direction of the rotation shaft.

  The developing device according to claim 10 replenishes the stirring and conveying member according to any one of claims 1 to 9 and the toner provided on the upstream side of the conveying direction of the spiral blade of the stirring and conveying member. A replenishing portion, the replenished toner and the circulated developer are agitated by the spiral blade provided on the downstream side of the replenishing portion, the agitated developer is supplied, and the developing roller holds the same And.

An image forming apparatus according to claim 11 has the developing device according to claim 10, and forms an image on a supplied recording medium.

According to the present invention, it is possible to provide a stirring and conveying member that prevents the developer from sticking and staying, a developing device using the same, and an image forming apparatus.

FIG. 1 is a schematic configuration view showing an image forming apparatus of an embodiment. It is a schematic diagram which shows the developing device of embodiment. FIG. 2 is a perspective view and a schematic view showing a developer stirring and conveying member of the embodiment. It is a schematic diagram which shows the developer stirring conveyance member of embodiment. It is a schematic diagram which shows the cross section of the developer stirring conveyance member of embodiment.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration view of an image forming apparatus using the stirring and conveying member and the developing device of the present invention. The image forming apparatus 1 according to the embodiment includes a control unit 2, a photoconductor 10, a charging unit 20, an exposure unit 30, a developing device 40, a transfer unit 50, a fixing unit 60, a cleaning unit 70, and a sheet storage unit 80. An image is formed on a sheet P, which is a recording medium, based on the supplied image information.

The control unit 2 includes an arithmetic device such as a CPU (Central Processing Unit) and a memory, and controls the operation of each component of the image forming apparatus 1.

The photosensitive member 10 is a cylindrical rotary member rotating in the direction of the arrow shown in FIG. 1 having a photosensitive layer formed of an organic photosensitive material for holding an image.

The charging unit 20 applies a predetermined charging voltage using a charging roll or the like that rotates in contact with the surface of the photosensitive member 10. The charging unit 20 may be a contact charging method in which charging is performed in contact with the photosensitive member 10 using a brush or the like, or a non-contact charging method in which the photosensitive member 10 is charged using corona discharge.

The exposure unit 30 irradiates light corresponding to image data on the surface of the photosensitive member 10 charged by the charging unit 20 to form an electrostatic latent image composed of a latent image potential based on a potential difference. The electrostatic latent image moves to a position where the developing device 40 is disposed as the photosensitive member 10 rotates.

The developing device 40 has a rotating developing roller 41, and the toner attracted to the developing roller 41 is transferred to the photosensitive member 10. That is, the toner moves to the surface of the photosensitive member 10 by the potential difference between the electrostatic latent image formed on the photosensitive member 10 and the charged toner. Thus, the toner image is formed on the photosensitive member 10, and this toner image moves to the position where the transfer unit 50 is disposed as the photosensitive member 10 rotates.

Further, inside the developing device 40, a developer stirring and conveying member 42 for stirring the toner T and the developer D, a developer supplying and conveying member 43 for supplying the developer D to the developing roll 41, a partition portion 44, and the toner T A replenishing unit 45 is provided for replenishing the developer agitating and conveying member 42. The detailed description of the developing device 40 and the developer stirring and conveying member 42 will be described later.

The transfer unit 50 transfers the toner image formed on the photosensitive member 10 onto the sheet P conveyed by the conveyance roll 91. The sheet P on which the toner image has been transferred is conveyed by the conveyance roll 91 to the fixing unit 60.

The fixing unit 60 includes a fixing roll 61 as a pressure-receiving body having a heat source, and a pressure roll 62 provided opposite to the fixing roll 61, and heats the unfixed toner image of the sheet P. And pressure to fix. The sheet P on which the toner image is fixed by the fixing unit 60 is conveyed and stored by the conveyance roll 91.

After the toner image is transferred onto the sheet P, the cleaning unit 70 removes toner and the like remaining on the surface of the photosensitive member 10. In the sheet storage unit 80, a plurality of sheets P are stored. The sheet P is taken out of the sheet storage unit 80 by the sheet feeding roller 90, and is conveyed to the transfer unit 50 by the conveying roller 91.

Next, the developing device 40 of the embodiment will be described. FIG. 2 is a schematic view showing the inside of the developing device 40 shown in FIG. As described above, the developing device 40 includes the developing roller 41, the developer stirring and conveying member 42, the developer supply and conveying member 43, the partition 44, and the replenishment unit 45.

The developing roller 41 is provided to face the photosensitive member 10 shown in FIG. 1 which holds and rotates the electrostatic latent image, holds the developer D, and develops the electrostatic latent image of the photosensitive member 10. The developer stirring and conveying member 42 stirs the developer D and the toner T supplied to the developer D.

The developer agitating / conveying member 42 is formed so as to extend helically around the axis of rotation about an axis 42a as the axis of rotation and the axis 42a, and overlaps in a cross section in a direction orthogonal to the axis of rotation And a double spiral blade 42b consisting of two spiral blades. The double spiral blade 42b is composed of a spiral blade 42b1 and a spiral blade 42b2. That is, the double spiral blade 42b is composed of two spiral blades 42b1 and 42b2 which differ in phase by 180 ° around the rotation axis of the shaft 42a.

The spiral blade 42b1 and the spiral blade 42b2 are separated by a plurality of discontinuous portions FR formed to be discontinuous in the extending direction, and the discontinuous portion FR, and the first spiral blade and the second spiral are formed. It comprises a plurality of blades BR which are formed to oppose each other as the blades. Further, in the discontinuous portion FR, the blades BR as the first spiral blade and the second spiral blade are arranged such that the phases around the rotation axis of the shaft 42a are different. Details of the developer agitating and conveying member 42 of the embodiment will be described later.

The developer supplying and conveying member 43 is formed to supply the developer D stirred and supplied from the developer stirring and conveying member 42 to the developing roller 41. The developer supply / conveying member 43 has a rotating shaft 43a and a spiral blade 43b provided on the shaft 43a.

The partition portion 44 is provided between the developer agitating and conveying member 42 and the developer supply and conveying member 43, and is disposed so as to separate them. Both side portions of the partition portion 44 are opened, and the developer D is circulated and conveyed.

The replenishing unit 45 is provided at the upstream end of the developer stirring and conveying member 42 so as to replenish the toner T from the side, the upper side, and the like. The toner T supplied from the supply unit 45 and the circulated developer D are agitated by the developer agitating and conveying member 42 provided on the downstream side of the replenishment unit 45, and the agitated developer is supplied to the developer supplying and conveying member 43 The developer is supplied to and held by the developing roller 41 via the

That is, the toner T contained in the developer D supplied to the developing roll 41 is used for development and consumed. In order to compensate for the consumed toner T, toner T for replenishment is supplied from the side surface, the upper side, and the like to the circulated developer D in the developer agitating and conveying member 42.

Next, the developer stirring and conveying member 42 according to the embodiment will be described with reference to FIG. FIG. 3A is a perspective view showing the developer stirring and conveying member 42. As shown in FIG. FIG. 3 (b) is an enlarged view of the developer stirring and conveying member 42 shown in FIG. 3 (a). FIG. 3C is a schematic view showing the development of the developer stirring and conveying member 42 in the circumferential direction.

In the upstream spiral blade 42b1 shown in FIG. 3A, the toner T supplied from the supply unit 45 shown in FIGS. 1 and 2 is conveyed downstream. Further, on the downstream side of the developer stirring and conveying member 42, a spiral blade 42b1 and a spiral blade 42b2 are provided so as to overlap in the axial direction of the shaft 42a.

In a portion where the spiral blade 42b1 and the spiral blade 42b2 are provided so as to overlap with each other, a plurality of discontinuous portions FR are periodically provided so that the spiral blades become discontinuous. Further, the above-described spiral blades divided at the discontinuous portion FR become a plurality of blades BR.

FIG. 3B is an enlarged view of a portion where the spiral blade 42b1 and the spiral blade 42b2 shown in FIG. 3A are provided so as to overlap in the axial direction of the shaft 42a. As shown in FIG. 3B, in the discontinuous portion FR, the developer D transported with the spiral blade 42b1 and the spiral blade 42b2 and the rotation is divided into two at the discontinuous portion FR.

The developer D1, which is one of the two-differentiated developer D, separates from the blade BR and is transported by the spiral blade 42b1 and the spiral blade 42b2 as shown in FIG. 3B. The developer D1 thus transported is delayed by one cycle by being separated from the blade BR.

The developer D2, which is the other of the two-differentiated developer D, is conveyed by the blade BR, and is conveyed by the spiral blade 42b1 and the spiral blade 42b2 as shown in FIG. 3 (b). The developer D2 conveyed in this manner is separated from the blade BR and mixed with the developer D separated from the blade BR one cycle earlier.

Further, as shown in FIG. 3B, it is preferable that the cross section DM of the blade BR in contact with the discontinuous portion FR be formed substantially in parallel with the axial direction of the shaft 42a. By doing this, a circumferential force due to the cross section DM of the blade BR can be applied to the developer D to increase the stirring property.

FIG. 3C is a development of the relationship between the spiral blade 42b1 and the spiral blade 42b2, and the vertical axis shows the circumferential direction of the shaft 42a and shows from 0 degrees to 360 degrees, and the horizontal axis is The spiral blade 42b1 and the spiral blade 42b2 are illustrated from the upstream side to the downstream side of the portion where the spiral blade 42b1 and the spiral blade 42b2 overlap in the axial direction of the shaft 42a.

As shown in FIG. 3C, in the discontinuous portion FR, the upstream end T1 and the downstream end T2 of the blade BR are disposed and formed so that the phase around the rotation axis of the shaft 42a is different. . That is, as shown in FIG. 3C, an angle K1 at which the winding direction of the blade BR intersects with the axial direction of the shaft 42a intersects with the longitudinal direction of the discontinuous portion FR and the axial direction of the shaft 42a. And the angle K2, which is an angle to be formed, are formed differently. In the embodiment, the angle K2 is formed to be substantially perpendicular. The angle KI and the angle K2 may be selected optimally in the relationship between developer agitation and transport.

Next, the blade BR of the developer stirring and conveying member 42 will be described with reference to FIG. FIG. 4A is a perspective view showing the developer stirring and conveying member 42. As shown in FIG. FIG.4 (b) is a schematic diagram which shows the cross section of the blade | wing BR of Fig.4 (a). FIG. 4C is a schematic view showing the flow of the developer. FIG. 4D is a schematic view showing the movement of the developer D in a portion where the spiral blade 42b1 and the spiral blade 42b2 overlap in the axial direction of the shaft 42a.

As shown in FIG. 4A, the spiral blade 42b1 and the spiral blade 42b2 of the developer stirring and conveying member 42 have, for example, a first region R1 as a convex inclined portion provided on the side surface of the blade BR. ing. That is, the first region R1 as the inclined portion is provided on at least one surface of the blade BR adjacent in the circumferential direction of the rotation axis of the shaft 42a so that the inclination changes with respect to the extending direction . The first region R1 is formed so that the axial length of the bottom surface in contact with the rotation axis of the blade BR continuously increases and decreases in a region overlapping in the axial direction of the shaft 42a. Therefore, the first region R1 is provided between the facing surfaces of the blades BR adjacent in the circumferential direction of the shaft 42a, and is formed as a region where the distance between the facing surfaces is narrow.

FIG. 4B is a schematic view for explaining the width H1 of the first region R1 and the width H2 of the second region R2 as the above-described inclined portion, and shows respective cross sections in the direction parallel to the axis 42a. ing. In the embodiment, as shown in FIG. 4B, the relationship between the width H1 of the first region R1 and the width H2 of the second region R2 is H1 ≧ H2.

FIG. 4C shows an example in which the developer D flows into the discontinuous portion FR and is divided into the developer D1 and the developer D2. The developer D passes through the first region R1 and the second region R2 before flowing into the discontinuous portion FR.

FIG. 4D shows the moving direction of the developer in the portion overlapping the spiral blade 42b1 and the spiral blade 42b2. As shown in FIG. 4D, in the portion where the flow path of the overlapping portion is narrowed, for example, the portion sandwiched by the first region R1 as the above-mentioned inclined portion, the developer D is Turbulent flow, sticking, retention, etc. are prevented. That is, in the vicinity of the first region R1, the developer D can be turbulently flowed by the change in the direction of the force received from the spiral blades 42b1 and 42b2 as compared with the other portions.

That is, in a region where two blades BR adjacent to each other in the axial direction of the shaft 42a overlap, as shown in FIG. 4 (d), the first region R1 and the second region R2 are provided. It is configured to have a point of increasing length.

FIG. 5 is a schematic view showing a cross section of the developer stirring and conveying member 42. As shown in FIG. In FIG. 5, the end a of the blade BR in the spiral blade 42b1 located at the cross-sectional portion of the shaft 42a and the end b of the blade BR opposed to the blade BR through the discontinuous portion FR are shown. ing. Further, in FIG. 5, the end c of the blade BR in the spiral blade 42b2 located in the cross-sectional portion of the shaft 42a, and the end d of the blade BR opposed to the blade BR through the discontinuous portion FR. Is shown.

As shown in FIG. 5, the angle between the end a and the end b with respect to the center of the shaft 42a is an angle A, and the angle between the end b and the end c with the center of the shaft 42a is an angle Assuming that B, in the embodiment, the relationship of B = 180−A is satisfied. The angle A is a path along which the developer D is transported at the portion of the discontinuous portion FR, and the angle B is a portion where the blades BR overlap in the axial direction.

That is, the angle formed with respect to the center of the rotation axis of the shaft 42a as the interval at which each blade BR is provided with the first region may be smaller than B. By doing this, the first region exists at one or more places in the facing surface of the blade BR in which the angle B is formed.

According to the above embodiment, by providing the double spiral blade 42b, compared to the configuration in which one spiral blade is provided, the conveyance surface for conveying the developer D is increased, and the conveyance capability in the axial direction is increased. Improve. Further, in the double spiral blade 42b, there is a portion overlapping in each circumferential direction, and there is a narrow portion between the spiral blade 42b1 and the spiral blade 42b2 of this portion.

In a portion where the spiral blade 42b1 having such a narrowed portion and the spiral blade 42b2 overlap, one or more locations where the bottom surfaces of these spiral blades continuously change are provided. With such a configuration, in the stirring of the developer, the direction in which the developer D is pushed by the wall surfaces of these spiral blades is continuously changed, and a turbulent flow is generated in the developer D. Is prevented.

Other Embodiments The above is the description of the developer stirring and conveying member 42, the developing device 40, and the image forming apparatus 1 according to the embodiment, but the present invention is not limited to the above embodiment, and the other embodiments are not limited. Embodiments are also possible. Hereinafter, other embodiments will be described.

In the embodiment, the developer agitating and conveying member 42 is configured to have two spiral blades, but is not limited thereto. For example, the developer stirring and conveying member 42 may be configured to have three or more spiral blades. In such a configuration having a plurality of spiral blades, the surface for conveying the developer is increased, and the conveyance capability in the axial direction is improved.

Further, the first region R1 provided on the side surface of the blade BR may be a concave inclined portion. Even in the case of such an inclined portion, the developer is conveyed in directions different from each other in the inclined portion to cause turbulent flow.

Reference Signs List 1 image forming apparatus 2 control unit 10 photosensitive member 20 charging unit 30 exposure unit 40 developing device 41 developing roller 42 developer stirring and conveying member 42a shaft 42b double spiral blade 42b1 and 42b2 spiral blade 43 developer supplying and conveying member 43a shaft 43b spiral Wings 44 Partitions 45 Refilling section 50 Transfer section 60 Fixing section 61 Fixing roll 62 Pressure roll 70 Cleaning section 80 Sheet storage section 90 Feeding roll 91 Transport roll P Paper T Toner D, D1, D2 Developer FR Discontinuous part BR Blade DM Section T1 Upstream end T2 Downstream end K1, K2 Angle R1 First area R2 Second area H1, H2 Width A, B Angle a, b, c, d End

Claims (11)

A spiral blade extending in a spiral shape around the rotation axis, a discontinuity provided such that the spiral blade is discontinuous, and a distance between the spiral blades is directed to the discontinuity An agitation conveying member characterized by having a portion that becomes wider as it extends. The stirring and conveying member according to claim 1, wherein an interval between the spiral blades becomes wider as it goes to the discontinuous portion by changing an axial width of a bottom surface of the spiral blade. 3. The stirring and conveying member according to claim 1, wherein an interval between the spiral blades becomes wider as it goes to the discontinuous portion by changing an inclination of a side surface of the spiral blade. The stirring conveyance member according to any one of claims 1 to 3, wherein in the discontinuous portion, the spiral blade has a different phase around a rotation axis. First and second flow paths adjacent to each other in the axial direction of the rotation axis, which are sandwiched between helical blades extending in a spiral shape around the rotation axis, the first flow path, and the second And a connecting portion connected to the flow path, wherein the width of the first flow path or the second flow path becomes wider toward the connecting portion. The stirring according to claim 5, wherein the first flow path or the second flow path becomes wider as it goes to the connection portion by changing an axial width of a bottom surface of the spiral blade. Conveying member. The stirring and conveying system according to claim 5 or 6, wherein the first flow path or the second flow path becomes wider as it goes to the connection portion by changing the inclination of the side surface of the spiral blade. Element. The stirring conveyance member according to any one of claims 5 to 7, wherein the spiral blade has different phases around the rotation axis at the connection portion. The stirring and conveying member according to any one of claims 5 to 8, wherein the spiral blade has a portion overlapping in a circumferential direction of the rotation shaft. A stirring and conveying member according to any one of claims 1 to 9, a replenishing unit provided on the upstream side of the conveying direction of the spiral blade of the stirring and conveying member, and a replenishing unit for replenishing the toner; And a developer roll for agitating the circulated developer with the spiral blade provided on the downstream side of the replenishing section and supplying the agitated developer and holding the developer. apparatus. An image forming apparatus comprising the developing device according to claim 10 and forming an image on a supplied recording medium.