JP2022110410A - Toner conveying device and image forming apparatus including the same - Google Patents

Abstract

To provide a toner conveying device that can suppress aggregation of toner stored in a toner conveying unit when the toner is conveyed by a toner conveying screw toward a toner discharge port from an upstream side to a downstream side in a conveyance direction of the toner, and an image forming apparatus including the same.SOLUTION: In a toner conveying screw of a toner conveying device, a first angle of a first surface on a downstream side in a toner conveyance direction of a blade part located in an end area among a plurality of blade parts with respect to an axis of rotation of the toner conveying screw is gradually increased from the upstream side toward the downstream side in the toner conveyance direction, alternatively, the blade part located in the end area among the plurality of blade parts becomes softer from the downstream side toward the upstream side in the toner conveyance direction.SELECTED DRAWING: Figure 4

Description

The present invention relates to a toner conveying device for conveying toner and an image forming apparatus including the same, such as a copying machine, a multifunction machine, a printer, and a facsimile machine.

A toner conveying device (toner cartridge) includes a toner conveying portion that conveys toner. The toner conveying portion is provided with a toner discharge port for discharging toner. Further, the toner conveying portion is often provided with a toner conveying screw for conveying the toner toward the toner discharge port so that the toner can be easily discharged from the toner discharge port.

In such a toner conveying device, the toner contained in the toner conveying portion is conveyed by the toner conveying screw from the upstream side toward the downstream side in the toner conveying direction toward the toner discharge port, so that the pressure applied to the toner increases. , the toner easily aggregates. As a result, the toner does not drop from the toner outlet and/or the toner is coagulated.

Regarding this point, Japanese Patent Application Laid-Open No. 2002-100001 discloses that the angle of inclination of the surface of the spiral blade located above the toner discharge port on the downstream side in the toner conveying direction with respect to the axial direction of the rotating shaft is A configuration is described in which the angle of inclination of the downstream side surface with respect to the axial direction of the rotating shaft is set to be smaller (see paragraph 0079 of Patent Document 1, FIG. 6A). Further, in Japanese Patent Laid-Open No. 2002-100002, the second inclination angle of the toner conveying screw with respect to the plane orthogonal to the rotation axis of the second spiral blade provided in the vicinity of the discharge port of the discharge portion of the conveying path is A configuration is described in which the first helical blade provided in the image forming area is set to have a larger inclination angle with respect to a plane orthogonal to the rotation axis [Patent Document 2, paragraph 0118, See FIG. 10].

Japanese Unexamined Patent Application Publication No. 2011-33702 JP 2017-215545 A

However, in the configurations described in Patent Documents 1 and 2, the toner contained in the toner conveying portion is conveyed by the toner conveying screw from the upstream side toward the downstream side in the toner conveying direction toward the toner outlet. More pressure is applied, which makes the toner more prone to agglomerate.

Therefore, according to the present invention, toner aggregation can be suppressed when the toner stored in the toner conveying portion is conveyed by the toner conveying screw from the upstream side to the downstream side in the toner conveying direction toward the toner outlet. An object of the present invention is to provide a toner conveying device and an image forming apparatus having the same.

In order to solve the above problems, the present invention provides a toner conveying device and an image forming apparatus according to the following first and second aspects.

(1) Toner Conveying Device According to First Aspect A toner conveying device according to a first aspect of the present invention is a toner conveying device that conveys toner, and includes a toner conveying portion provided with a toner discharge port for discharging the toner. and a toner conveying screw provided in the toner conveying portion for conveying the toner accommodated in the toner conveying portion toward the toner discharge port, wherein the toner conveying screw corresponds to the toner discharge port. A plurality of blade portions each corresponding to one round of the spiral blade of the toner conveying screw in a predetermined end region on the upstream side from the downstream end portion in the toner conveying direction, including at least an outlet region. Among them, the first surface of the blade portion located in the end region on the downstream side in the toner conveying direction has a first angle with respect to the rotation axis of the toner conveying screw from the upstream side to the downstream side in the toner conveying direction. It is characterized by increasing in size as it goes.

(2) Toner Conveying Device of Second Aspect A toner conveying device of a second aspect of the present invention is a toner conveying device that conveys toner, and includes a toner conveying portion provided with a toner discharge port for discharging the toner. and a toner conveying screw provided in the toner conveying portion for conveying the toner accommodated in the toner conveying portion toward the toner outlet, wherein the spiral blade of the toner conveying screw has a hardness equal to or higher than a predetermined hardness. The toner conveying screw includes at least a toner discharge port region corresponding to the toner discharge port among a plurality of blade portions each corresponding to one rotation of the spiral blade, and The vane portion located in a predetermined end region on the upstream side from the downstream end in the toner conveying direction is softened from the downstream side to the upstream side in the toner conveying direction.

(3) Image Forming Apparatus According to the present invention, there is provided an image forming apparatus including the toner conveying device according to the first aspect or the second aspect of the present invention.

According to the present invention, when the toner contained in the toner conveying portion is conveyed by the toner conveying screw from the upstream side to the downstream side in the toner conveying direction toward the toner outlet, it is possible to suppress aggregation of the toner. Become.

1 is a schematic cross-sectional view of an image forming apparatus according to an exemplary embodiment viewed from the front; FIG. FIG. 2 is a perspective view of an example of a toner conveying device as viewed obliquely from above on the front side; FIG. 2 is a perspective view of an example of a toner conveying device as viewed obliquely from below on the front side; FIG. 3 is a perspective view of the toner conveying device shown in FIGS. 2A and 2B from which a top cover is removed, as viewed obliquely from above on the front side; 3B is a cross-sectional view of the toner conveying device shown in FIG. 3A taken along line BB. FIG. 3B is a cross-sectional view of the toner conveying device shown in FIG. 3A taken along line CC. FIG. FIG. 2 is a cross-sectional view showing the pressure reducing portion side of the toner conveying screw according to the first embodiment; FIG. 11 is a cross-sectional view showing a pressure reducing portion side of a toner conveying screw according to a second embodiment; FIG. 11 is a cross-sectional view schematically showing a pressure reducing portion of a toner conveying screw according to a third embodiment; FIG. 14 is a cross-sectional view schematically showing a pressure reducing portion of a toner conveying screw according to a fourth embodiment; FIG. 14 is a cross-sectional view schematically showing a pressure reducing portion of a toner conveying screw according to a fifth embodiment; FIG. 14 is a cross-sectional view schematically showing a pressure reducing portion of a toner conveying screw according to a sixth embodiment; FIG. 14 is a cross-sectional view schematically showing a pressure reducing portion of a toner conveying screw according to a seventh embodiment; FIG. 21 is a cross-sectional view schematically showing a pressure reducing portion of a toner conveying screw according to an eighth embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments according to the present invention will be described below with reference to the drawings. In the following description, the same parts are given the same reference numerals. Their names and functions are also the same. Therefore, a detailed description thereof will not be repeated.

[Image forming apparatus]
FIG. 1 is a schematic cross-sectional view of an image forming apparatus 100 according to the present embodiment as viewed from the front. In the figure, the symbol X represents the left-right direction, the symbol Y the depth direction, and the symbol Z the up-down direction (vertical direction).

The image forming apparatus 100 according to the present embodiment is a color image forming apparatus that forms multicolor and monochromatic images on a sheet P such as paper. The image forming apparatus 100 performs image forming processing according to image data read by the document reading device 90 or image data transmitted from the outside. Note that the image forming apparatus 100 may be a color image forming apparatus of another type. Also, the image forming apparatus 100 may be a monochrome image forming apparatus.

The image forming apparatus 100 includes a document reading device 90 and an image forming apparatus main body 110 . An image forming unit 102 and a sheet conveying system 103 are provided in the image forming apparatus main body 110 .

The image forming section 102 includes an exposure unit 1, a plurality of developing devices 2 and 2 (developing units), a plurality of photoreceptor drums 3 and 3 acting as electrostatic latent image carriers, a plurality of photoreceptor cleaning units 4 and 4, A plurality of charging devices 5 to 5, an intermediate transfer belt device 6, a belt cleaning device 40, a plurality of toner conveying devices 21 to 21 (toner cartridges), and a fixing unit 7 are provided.

The image data handled by the image forming apparatus 100 corresponds to a color image using a plurality of colors (black (K), cyan (C), magenta (M), and yellow (Y) in this example). . Therefore, the developing devices 2 and 2, the photoreceptor drums 3 and 3, the photoreceptor cleaning units 4 and 4, the charging devices 5 and 5, and the intermediate transfer rollers 65 and 65 are of a plurality of types (four types in this example) corresponding to each color. A plurality (four in this example) of image forming stations Pa to Pd are configured to form a plurality of (four in this example) image forming stations Pa to Pd.

Also, the sheet conveying system 103 includes a paper feeding device 81 , a discharge roller 31 and a discharge tray 14 . The intermediate transfer belt device 6 has intermediate transfer rollers 65 to 65 and an intermediate transfer belt 61 . The intermediate transfer rollers 65 to 65 are provided inside the intermediate transfer belt 61 . The intermediate transfer belt 61 rotates in a predetermined rotation direction M. As shown in FIG. The intermediate transfer rollers 65 to 65 transfer the toner images of respective colors formed on the surfaces of the photosensitive drums 3 to 3 onto the intermediate transfer belt 61 while being driven to rotate as the intermediate transfer belt 61 rotates.

A document reading device 90 for reading an image of a document (not shown) is provided on the upper portion of the image forming apparatus main body 110 . The document reader 90 includes a document table 92 on which a document is placed. The document table 92 is made of transparent glass. The document image read by the document reading device 90 is sent to the image forming apparatus main body 110 as image data, and the image is recorded on the sheet P. FIG.

A sheet conveying path W<b>1 is provided in the image forming apparatus main body 110 . The sheet feeding device 81 supplies the sheet P to the sheet conveying path W1. The sheet conveying path W1 guides the sheet P to the discharge tray 14 via the transfer roller 10 and the fixing unit 7 of the secondary transfer device. The fixing unit 7 fixes the toner image formed on the sheet P to the sheet P by heating. A pickup roller 11a, a plurality of transport rollers 12a to 12a, a registration roller 13, a transfer roller 10, a heat roller 71 and a pressure roller 72 in the fixing unit 7, and a discharge roller 31 are arranged near the sheet transport path W1. there is

In the image forming apparatus 100, the sheet P supplied by the paper feeding device 81 is conveyed to the registration roller 13 via the conveying rollers 12a to 12a. Next, the sheet P is conveyed to the transfer roller 10 at the timing when the sheet P and the toner image on the intermediate transfer belt 61 are aligned by the registration roller 13 , and the toner image is transferred onto the sheet P by the transfer roller 10 . After that, the sheet P passes through the heat roller 71 and the pressure roller 72 in the fixing unit 7 and is discharged onto the discharge tray 14 via the transport rollers 12 a and 12 a and the discharge roller 31 . When an image is formed not only on the front surface of the sheet P but also on the back surface, the sheet P is conveyed in the reverse direction from the discharge roller 31 to the reverse sheet conveying path W2. The sheet P passes through the reversing conveying rollers 12b to 12b, the front and back of the sheet P is reversed, and the sheet P is led to the registration rollers 13 again. After a toner image is formed and fixed on the back surface of the sheet P in the same manner as the front surface, the sheet P is discharged toward the discharge tray 14 .

The developing devices 2-2 develop the electrostatic latent images on the photosensitive drums 3-3 with a two-component developer containing toner and carrier as main components.

Photoreceptor cleaning units 4-4 collect residual toner remaining on intermediate transfer belt 61 without being transferred onto sheet P by intermediate transfer rollers 65-65 as waste toner. The belt cleaning device 40 collects residual toner remaining on the intermediate transfer belt 61 without being transferred onto the sheet P by the transfer roller 10 as waste toner.

In the image forming apparatus 100, the toner conveying devices 21 to 21 are detachable from the image forming apparatus main body 110. As shown in FIG. In the image forming apparatus 100, the toner is supplied from the toner conveying devices 21 to 21 to the developing devices 2 and 2 so that the toner ratio of the two-component developer is substantially constant, and the electrostatic latent on the photosensitive drums 3 and 3. The image is developed in developer units 2-2. The toner conveying devices 21 to 21 are detachably attached to the image forming apparatus main body 110 .

(toner conveying device)
Next, the toner conveying device 21 according to this embodiment will be described below with reference to FIGS. 2A to 11. FIG.

2A and 2B are a perspective view of an example of the toner conveying device 21 viewed obliquely from above the front side and a perspective view of the toner conveying device 21 viewed from obliquely below the front side, respectively. Note that FIG. 2B shows a state in which the shutter member 21b1 is open. FIG. 3A is a perspective view of the toner conveying device 21 shown in FIGS. 2A and 2B from which the top lid 212 is removed, as seen obliquely from above the front side. FIG. 3B is a cross-sectional view of the toner conveying device 21 shown in FIG. 3A along line BB. 3C is a cross-sectional view of the toner conveying device 21 shown in FIG. 3A along line CC.

The image forming apparatus 100 includes a toner conveying device 21 that conveys toner. The toner conveying device 21 includes a toner conveying portion 211 (specifically, a housing), an upper lid 212, a toner stirring portion 213, and a toner conveying screw 214, which are made of resin. The toner conveying portion 211 accommodates toner. The upper lid 212 closes the upper opening 211 a of the toner conveying portion 211 . The upper lid 212 is fixed to the opening 211a of the toner conveying portion 211 with a bonding member such as an adhesive.

The toner conveying portion 211 is provided with a toner discharge port 21a for discharging toner downward. In this example, in order to prevent toner from leaking from the toner discharge port 21a when the toner conveying device 21 is detached from the image forming apparatus main body 110, the toner discharge port 21a is provided with sealing means (a shutter mechanism in this example). 21b) is provided. The shutter mechanism 21b has a shutter member 21b1. The shutter member 21b1 opens when the toner conveying device 21 is attached to the image forming apparatus main body 110 to open the toner discharge port 21a. On the other hand, the shutter member 21b1 closes when the toner conveying device 21 is detached from the image forming apparatus main body 110 to block the toner discharge port 21a.

Toner agitating portion 213 agitates toner contained in toner conveying portion 211 and sends the toner to toner conveying screw 214 . The toner stirring section 213 has a rotating shaft 213a and a stirring member 213b.

The toner agitating portion 213 agitates the toner by rotating the rotating shaft 213a and rotating the agitating member 213b. The stirring member 213b has flexibility, and stirs the toner accommodated in the toner conveying device 21 while rotating in a predetermined rotational direction R1 (counterclockwise direction in FIGS. 3A and 3B) about the rotation axis Q1. . One end of the stirring member 213b in the lateral direction is provided on the rotating shaft 213a.

The toner conveying screw 214 is provided in the toner conveying portion 211 and conveys the toner accommodated in the toner conveying portion 211 toward the toner outlet 21a. That is, the toner conveying screw 214 conveys the toner toward the end in the toner conveying direction H (back side in this example), which is the direction of the rotation axis Q1 of the toner conveying device 21 . The toner conveying screw 214 has a rotating shaft 214a and a spiral blade 214b.

The toner conveying screw 214 conveys toner by rotating a rotating shaft 214a and rotating a spiral blade 214b. The toner conveying screw 214 rotates about the rotational axis Q2 in a predetermined rotational direction R2 (clockwise direction in FIGS. 3A and 3B) and feeds the toner from the toner agitating section 213 to the toner supply port of the developing device 2 ( 2B and 3B) communicating with a toner outlet 21a (not shown). One end of the spiral blade 214b in the lateral direction is provided on the rotating shaft 214a. The toner conveying screw 214 replenishes the toner accommodated in the toner conveying portion 211 from the toner discharge port 21a to the toner supply port of the developing device 2 . When the toner conveying device 21 is detached from the image forming apparatus main body 110, the toner discharge port 21a is closed by a shutter member 21b1 (see FIGS. 2A, 2B, and 3B) so that the toner conveying device 21 is removed from the image forming apparatus main body 110. When it is attached from 110, it is opened by the shutter member 21b1.

A rotating shaft 213a of the toner stirring unit 213 and a rotating shaft 214a of the toner conveying screw 214 are rotatably supported by the toner conveying unit 211 about rotation axes Q1 and Q2 along the depth direction Y. As shown in FIG. The rotary shafts 213 a and 214 a protrude outward on both sides in the depth direction Y of the toner conveying portion 211 . Engagement portions 213c and 214c (see FIG. 3C) are provided at the rear side end portions of the rotating shafts 213a and 214a. Rotational driving force from a driving portion (not shown) is transmitted to engaging portions 213c and 214c on the rear side ends of the rotating shafts 213a and 214a.

[Structure of Toner Conveying Screw]
The toner conveying screw 214 according to the present embodiment includes at least a toner discharge port region α (see FIG. 3C) corresponding to the toner discharge port 21a, and is located upstream from the downstream end 2141 in the toner conveying direction H. has a pressure reducing portion 200 for reducing the pressure on the toner in a predetermined end region β1 (see FIG. 3C). Here, the pressure reducing portion 200 can be exemplified by about 1/5 to 1/3 of the entire length of the toner conveying screw 214 .

According to the present embodiment, the toner conveying screw 214 has the pressure reducing portion 200 in the end region β1. As the toner is conveyed from the upstream side toward the downstream side of H toward the toner discharge port 21a, the pressure applied to the toner can be reduced, and the toner can be prevented from agglomerating accordingly. Therefore, it is possible to effectively prevent the toner from falling from the toner outlet 21a and/or the toner from solidifying.

(First embodiment)
FIG. 4 is a cross-sectional view showing the pressure reducing portion 200 (200A) side of the toner conveying screw 214 (214A) according to the first embodiment.

By the way, a plurality of blade portions 214d to 214d corresponding to one rotation of the spiral blade 214b in the toner conveying screw 214 are arranged to convey the toner on the first surfaces 214d1 to 214d1 (toner conveying surface) on the downstream side in the toner conveying direction H. The smaller the first angle .theta. of the screw 214 with respect to the rotation axis Q2, the more the toner is conveyed in the direction intersecting the rotation axis Q2. It exhibits a conveying function of conveying in the conveying direction H of the toner.

In this regard, in the present embodiment, the pressure reduction unit 200 (200A) is configured so that the first angles θ(1) to θ(n) (n is an integer of 2 or more, n=5 in this example) are used to convey the toner. The first angle θ(n)< .

As a result, the toner is gradually moved from the cross direction toward the toner discharge port 21a from the upstream side to the downstream side in the toner conveying direction H in the end region β1 in the toner conveying direction H along the direction of the rotation axis Q2. can be transferred. As a result, the toner is conveyed from the upstream side to the downstream side toward the toner discharge port 21a, so that the pressure applied to the toner can be further reduced.

In the present embodiment, the upstream second surfaces 214d2 to 214d2 (surfaces opposite to the toner transport surface) of the blade portions 214d to 214d located in the end region β1 in the toner transport direction H are rotated relative to the rotation axis Q2. The second angle γ is constant.

By doing so, the direction in which the toner moves on the second surfaces 214d2 to 214d2 of the blade portions 214d to 214d can be made constant. can be stably conveyed toward

By the way, from the viewpoint of improving the toner conveying ability, it is desirable to increase the amount of toner between the adjacent blade portions 214d, 214d as much as possible.

In this regard, in the present embodiment, the second angles γ to γ are approximately 90 degrees. By doing so, the amount of toner between the adjacent blade portions 214d, 214d can be increased as much as possible, thereby improving the toner conveying ability.

In this embodiment, the first angles θ(1) to θ(n) are set within a predetermined first angle range for each of the blade portions 214d to 214d. In this example, the first angle θ(1) is over 80° and 90° or less, the first angle θ(2) is over 70° and 80° or less, and the first angle θ(3) is 60°. The first angle θ(4) is set in a first angle range of more than 50° and 60° or less, and the first angle θ(5) is set in a first angle range of more than 40° and 50° or less.

By doing so, the first angles θ(1) to θ(n) can be reliably increased from the upstream side toward the downstream side in the toner transport direction H.

By the way, in the region β2 other than the end region β1, the toner is less affected by pressure than in the end region β1.

In this regard, in the present embodiment, the first angle θ The first angle range set to .theta. Same as range.

By doing so, in the blade portions 214d to 214d (214x) located in the region β2 other than the end region β1 where the toner is less affected by pressure among the plurality of blade portions 214d to 214d, the region β2 other than the end region β1 Toner can be transported with the same or substantially the same transport function as the vane portion 214d (214y) located at the most upstream position in . As a result, the toner transport state can be gradually changed between the end region β1 and the region β2 other than the end region β1. Accordingly, the toner can be smoothly conveyed between the end region β1 and the region β2 other than the end region β1.

(Second embodiment)
FIG. 5 is a cross-sectional view showing the pressure reducing portion 200 (200A) side of the toner conveying screw 214 (214B) according to the second embodiment. In the toner conveying screw 214 (214B) according to the second embodiment, different points from the first embodiment will be mainly described.

In the second embodiment, the first angles θ to θ of the blade portions 214d to 214d (214x) located in the region β2 other than the end region β1 among the plurality of blade portions 214d to 214d in the toner conveying screw 214 (214B) The set first angle range is the same as the first angle range set for the first angle θ(1) of the blade portion 214d (214z) located at the most downstream position in the toner conveying direction H of the end region β1. is.

By doing so, in the blade portions 214d to 214d (214x) located in the region β2 other than the end region β1 where the toner is less affected by pressure among the plurality of blade portions 214d to 214d, the region β2 other than the end region β1 Toner can be transported by the same or substantially the same transport function as the blade portion 214d (214z) located at the most downstream position in the . By doing so, it is possible to differentiate the toner conveying state between the end region β1 and the region β2 other than the end region β1. As a result, the toner can be reliably dispersed between the end region β1 and the region β2 other than the end region β1.

(Third embodiment)
FIG. 6 is a cross-sectional view schematically showing the pressure reducing portion 200 (200B) portion of the toner conveying screw 214 (214C) according to the third embodiment. The toner conveying screw 214 (214C) according to the third embodiment will be described with a focus on the differences from the first and second embodiments.

In the third embodiment, the spiral blade 214b of the toner conveying screw 214 (214C) is made of an elastic member having a predetermined hardness or more. Here, the elastic member can typically be a rubber member such as urethane rubber and chloroprene rubber (CR rubber). The hardness of the elastic member can be about 70 degrees to 90 degrees, more preferably 80 degrees to 87 degrees. In this example, the blade portions 214d to 214d are formed in a rectangular shape when viewed in cross section.

The pressure reducing portion 200 (200B) gradually or stepwisely decreases the blade portions 214d to 214d located in the end region β1 among the plurality of blade portions 214d to 214d from the downstream side to the upstream side in the toner conveying direction H. softened. For example, as the spiral blade 214b, a plurality of (for example, five or more) spiral members having different hardness gradually or stepwise can be connected. In this example, the blade portions 214d to 214d are formed in a rectangular shape when viewed in cross section.

By doing so, the flexibility (flexibility) of the blade portions 214d to 214d can be decreased from the upstream side to the downstream side in the toner conveying direction H in the end region β1 toward the toner discharge port 21a. Therefore, in the end region β1, the toner is gradually transferred from the upstream side to the downstream side in the toner conveying direction H toward the toner discharge port 21a in the direction intersecting the rotation axis Q2. can be transferred to H. As a result, the toner is conveyed from the upstream side to the downstream side toward the toner discharge port 21a, so that the pressure applied to the toner can be further reduced.

(Fourth embodiment)
FIG. 7 is a cross-sectional view schematically showing the pressure reducing portion 200 (200C) portion of the toner conveying screw 214 (214D) according to the fourth embodiment. In the toner conveying screw 214 (214D) according to the fourth embodiment, different points from the first to third embodiments will be mainly described.

In the fourth embodiment, the spiral blade 214b of the toner conveying screw 214 (214D) is made of an elastic member having a predetermined hardness or more. Here, the same material as that of the third embodiment can be used as the elastic member. The hardness of the elastic member can also be the same hardness as in the third embodiment.

In the pressure reducing portion 200 (200C), the roots (rotation shaft 214a side) of the blade portions 214d to 214d located in the end region β1 among the plurality of blade portions 214d to 214d are arranged from the upstream side to the downstream side in the toner conveying direction H. It becomes thicker gradually or step by step as it goes to . For example, as the spiral blade 214b, a plurality of (for example, five or more) spiral members having different hardness gradually or stepwise can be connected. In this example, the blade portions 214d to 214d are formed in a rectangular shape and a trapezoidal shape when viewed in cross section.

By doing so, the flexibility (flexibility) of the blade portions 214d to 214d can be decreased from the upstream side to the downstream side in the toner conveying direction H in the end region β1 toward the toner discharge port 21a. Therefore, in the end region β1, the toner is gradually conveyed along the direction of the rotation axis Q2 from the direction intersecting the rotation axis Q2 toward the toner discharge port 21a from the upstream side to the downstream side in the toner conveyance direction H. It can be moved in direction H. As a result, the toner is conveyed from the upstream side to the downstream side toward the toner discharge port 21a, so that the pressure applied to the toner can be further reduced.

(Fifth embodiment)
FIG. 8 is a cross-sectional view schematically showing the pressure reducing portion 200 (200D) portion of the toner conveying screw 214 (214E) according to the fifth embodiment.

The toner conveying screw 214 (214E) according to the fifth embodiment is a combination of the third embodiment and the fourth embodiment.

By doing so, it is possible to easily adjust the hardness of each of the blade portions 214d to 214d in the end region β1.

(Sixth embodiment)
FIG. 9 is a cross-sectional view schematically showing the pressure reducing portion 200 (200E) portion of the toner conveying screw 214 (214F) according to the sixth embodiment. In the toner conveying screw 214 (214F) according to the sixth embodiment, different points from the first to fifth embodiments will be mainly described.

In the sixth embodiment, the end region β1 is composed of a first end region β11 including at least the toner outlet region α, and a second end region β12 other than the first end region β11. Among the plurality of blade portions 214d to 214d, the blade portions 214d to 214d located in the first end region β11 are made of a rigid member having a hardness smaller than a predetermined hardness, and the blade portions 214d to 214d located in the second end region β12 214d is composed of an elastic member having a predetermined hardness or more. Here, for the elastic member, materials similar to those used in the third and fourth embodiments can be used. The hardness of the elastic member can also be in the same hardness range as in the third and fourth embodiments. As the rigid member, for example, resin materials and metal materials that have been generally used in the past can be used.

The pressure reducing portion 200 (200E) is gradually reduced as the blade portions 214d to 214d located in the second end region β12 among the plurality of blade portions 214d to 214d move upstream from the toner discharge port 21a in the toner conveying direction H. Or it is getting softer in stages. For example, as the spiral blade 214b, a plurality of (for example, five or more) spiral members having different hardness gradually or stepwise can be connected. In this example, the blade portions 214d to 214d are formed in a rectangular shape when viewed in cross section.

By doing this, the flexibility (flexibility) of the blade portions 214d to 214d made of an elastic member increases in the second end region β12 from the upstream side to the downstream side in the toner conveying direction H toward the toner discharge port 21a. can be made smaller. Therefore, in the second end region β12, the toner is gradually distributed along the direction of the rotation axis Q2 from the direction intersecting the rotation axis Q2 toward the toner discharge port 21a from the upstream side to the downstream side in the toner conveying direction H. can be shifted in the conveying direction H of . As a result, the toner is conveyed from the upstream side to the downstream side toward the toner discharge port 21a, so that the pressure applied to the toner can be further reduced. Further, the blades 214d to 214d made of a rigid member in the first end region β11 can reliably convey the toner toward the toner discharge port 21a.

(Seventh embodiment)
FIG. 10 is a cross-sectional view schematically showing the pressure reducing portion 200 (200F) portion of the toner conveying screw 214 (214G) according to the seventh embodiment. In the toner conveying screw 214 (214G) according to the seventh embodiment, different points from the sixth embodiment will be mainly described.

In the present embodiment, the blade portions 214d to 214d located in the first end region β11 are made of a rigid member having a hardness smaller than a predetermined hardness, and the blade portions 214d to 214d located in the second end region β12 The blade portions 214d to 214d located are made of an elastic member having a predetermined hardness or more. Here, the same material as that of the seventh embodiment can be used as the elastic member. The hardness of the elastic member can also be in the same hardness range as in the seventh embodiment.

In the pressure reducing portion 200 (200F), the roots (rotation shaft 214a side) of the blade portions 214d to 214d located in the second end region β12 among the plurality of blade portions 214d to 214d are positioned from the upstream side in the toner conveying direction H. It gradually or stepwise widens as it approaches the toner discharge port 21a toward the downstream side. For example, as the spiral blade 214b, a plurality of (for example, five or more) spiral members having different hardness gradually or stepwise can be connected.
In this example, the blade portions 214d to 214d are formed in a trapezoidal shape when viewed in cross section.

By doing this, the flexibility (flexibility) of the blade portions 214d to 214d made of an elastic member increases in the second end region β12 from the upstream side to the downstream side in the toner conveying direction H toward the toner discharge port 21a. can be made smaller. Therefore, in the second end region β12, the toner is gradually distributed along the direction of the rotation axis Q2 from the direction intersecting the rotation axis Q2 toward the toner discharge port 21a from the upstream side to the downstream side in the toner conveying direction H. can be shifted in the conveying direction H of . As a result, the toner is conveyed from the upstream side to the downstream side toward the toner discharge port 21a, so that the pressure applied to the toner can be further reduced. Further, the blades 214d to 214d made of a rigid member in the first end region β11 can reliably convey the toner toward the toner discharge port 21a.

(Eighth embodiment)
FIG. 11 is a cross-sectional view schematically showing the pressure reducing portion 200 (200G) portion of the toner conveying screw 214 (214H) according to the eighth embodiment.

The toner conveying screw 214 (214H) according to the eighth embodiment is a combination of the sixth embodiment and the seventh embodiment.

By doing so, it is possible to easily adjust the hardness of each of the blade portions 214d to 214d in the second end region β12.

The present invention is not limited to the embodiments described above, but can be implemented in various other forms. Therefore, the embodiment concerned is merely an example in all respects, and should not be construed in a restrictive manner. The scope of the present invention is indicated by the claims and is not restricted by the text of the specification. Furthermore, all modifications and changes within the equivalence range of claims are within the scope of the present invention.

100 Image forming apparatus 2 Developing device 200 Pressure reducing unit 21 Toner conveying device 211 Toner conveying unit 211a Opening 212 Top cover 213 Toner stirring unit 213a Rotating shaft 213b Stirring member 213c Engaging unit 214 Toner conveying screw 2141 End 214a Rotating shaft 214b Spiral blade 214d Blade portion 214d1 First surface 214d2 Second surface 21a Toner discharge port 21b Shutter mechanism 21b1 Shutter member H Conveyance direction P Sheet Q1 Rotational axis Q2 Rotational axis R1 Rotational direction R2 Rotational direction X Horizontal direction Y Depth direction Z Vertical direction α Toner discharge Exit region β1 End region β11 First end region β12 Second end region β2 Region other than end region θ First angle γ Second angle

Claims (11)

A toner conveying device for conveying toner,
a toner conveying portion provided with a toner discharge port for discharging the toner; and a toner conveying screw provided in the toner conveying portion for conveying the toner accommodated in the toner conveying portion toward the toner discharge port. prepared,
The toner conveying screw includes at least a toner discharge port region corresponding to the toner discharge port, and has a spiral shape in a predetermined end region on the upstream side from the downstream end in the toner conveying direction. Among the plurality of blade portions each corresponding to one rotation of the blade, the first surface of the blade portion located in the end region on the downstream side in the toner conveying direction is the first surface with respect to the rotation axis of the toner conveying screw. A toner conveying device, wherein the angle increases from the upstream side toward the downstream side in the toner conveying direction. The toner conveying device according to claim 1,
A toner conveying device, wherein a second angle of a second surface on an upstream side in the toner conveying direction of the blade portion located in the end region with respect to the rotation axis is constant. The toner conveying device according to claim 2,
The toner conveying device, wherein the second angle is approximately 90 degrees. The toner conveying device according to any one of claims 1 to 3,
The toner conveying device, wherein the first angle is set within a predetermined first angle range for each of the plurality of blade portions. The toner conveying device according to claim 4,
Among the plurality of blade portions, the first angle range set to the first angle of the blade portion located in a region other than the end region is the most upstream in the toner conveying direction of the end region. and the first angle range is the same as the first angle range set for the first angle of the blade portion located at the position. The toner conveying device according to claim 4,
Among the plurality of blade portions, the first angle range set to the first angle of the blade portion positioned in a region other than the end region is the most downstream of the end region in the toner conveying direction. and the first angle range is the same as the first angle range set for the first angle of the blade portion located at the position. A toner conveying device for conveying toner,
a toner conveying portion provided with a toner discharge port for discharging the toner; and a toner conveying screw provided in the toner conveying portion for conveying the toner accommodated in the toner conveying portion toward the toner discharge port. prepared,
The spiral blade of the toner conveying screw is composed of an elastic member having a predetermined hardness or higher,
The toner conveying screw includes at least a toner discharge port region corresponding to the toner discharge port among a plurality of blade portions each corresponding to one rotation of the spiral blade, and has a downstream side in the toner conveying direction. The toner conveying device, wherein the blade portion located in a predetermined end region on the upstream side from the end portion becomes softer from the downstream side toward the upstream side in the toner conveying direction. The toner conveying device according to claim 7,
The spiral blade of the toner conveying screw is composed of an elastic member having a predetermined hardness or higher,
Among a plurality of blade portions each corresponding to one round of the spiral blade, the base of the blade portion located in the end region is thickened from the upstream side to the downstream side in the toner conveying direction. A toner transport device characterized by: The toner conveying device according to claim 7 or 8,
The end region is composed of a first end region including at least the toner outlet region and a second end region other than the first end region,
A plurality of blade portions each corresponding to one turn of a spiral blade in the toner conveying screw are configured such that the blade portion positioned in the first end region is made of a rigid member having a hardness smaller than a predetermined hardness, and the blade portion located in the end region is made of an elastic member having a hardness equal to or higher than the predetermined hardness;
The toner conveying device, wherein the blade portion located in the second end region among the plurality of blade portions becomes softer as it becomes farther upstream from the toner outlet in the toner conveying direction. The toner conveying device according to any one of claims 7 to 9,
The end region is composed of a first end region including at least the toner outlet region and a second end region other than the first end region,
A plurality of blade portions each corresponding to one turn of a spiral blade in the toner conveying screw are configured such that the blade portion positioned in the first end region is made of a rigid member having a hardness smaller than a predetermined hardness, and the blade portion located in the end region is made of an elastic member having a hardness equal to or higher than the predetermined hardness;
Among the plurality of blade portions, the base of the blade portion located in the second end region is thickened toward the toner discharge port from the upstream side to the downstream side in the toner conveying direction. Toner transport device. An image forming apparatus comprising the toner conveying device according to any one of claims 1 to 10.

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