Powder storage device, and image forming apparatus including the powder storage device

Abstract

To provide a powder storage device, and an image forming apparatus including the powder storage device.SOLUTION: A powder storage device comprises: a housing that is formed with an internal space and an exhaust port located on a lower side of the internal space; a conveying screw that conveys powder from one side in an axial direction to the other side in the axial direction, and has a portion arranged on an upper side of the exhaust port; and a wall that covers the conveying screw from the outside in a radial direction, partitions the internal space into a storage chamber in which powder is stored and a conveyance path in which the conveying screw is stored and communicating with the storage chamber through an opening on one side and communicating with the exhaust port on the other side, and has a notch formed from an area where the exhaust port is formed toward one side in the axial direction.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to a powder containing device and an image forming apparatus including the powder containing device. [Background technology]

[0002] Generally, electrophotographic image forming apparatuses develop electrostatic latent images formed on an image carrier such as a photosensitive drum using developer supplied from a developing device to the surface of the image carrier. As a source of developer to the developing device, a powder containing device is provided, which includes a containing section for containing developer and having an outlet for discharging the developer, and an agitating member for agitating the developer and conveying it to the outlet. A toner cartridge that is detachably attached to the image forming apparatus is widely used as the powder containing device, for example.

[0003] For example, Patent Document 1 discloses a toner cartridge detachably attached to an image forming apparatus as a powder storage device. The toner cartridge is installed above a developing device across an intermediate transfer belt. The toner cartridge includes a toner container that stores developer, and a toner transport screw is installed inside the container as an agitator. A portion of one end of the toner transport screw downstream of the toner transport screw in the toner transport direction protrudes outward from the toner container and is located inside a toner discharge mechanism, which is a horizontal transport path for transporting a constant amount of toner (developer) from one end to the other end in the axial direction. Below one end of the toner transport screw, toner is discharged from the toner cartridge through a toner discharge port provided at the bottom of the toner discharge mechanism. The toner discharge mechanism is located so as not to overlap the image forming unit in the vertical direction, and a toner supply pipe is installed next to the image forming unit, connecting the toner discharge port to the developing device. The toner discharged from the toner discharge port is replenished to the developing device via the toner supply pipe. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-014763 Summary of the Invention [Problem to be solved by the invention]

[0005] As image forming devices become smaller, their internal volumes become smaller, creating a need for powder storage devices designed to fit within the limited space within the image forming device. However, the toner cartridge described in Patent Document 1, which includes a toner discharge mechanism that serves as a horizontal transport path for stabilizing the flow rate of developer transported by the transport screw, protrudes outward, requiring space within the image forming device to accommodate such a protrusion. Furthermore, space is also required for a toner supply pipe connecting the toner outlet and the developing device. Therefore, for example, a vertical powder storage device with a storage section that is larger vertically than horizontally may be adopted and placed to the side of the image forming unit and the developing device. In such a powder storage device, the toner supply pipe is omitted by directly connecting the powder storage device to the developing device. Furthermore, the transport screw and toner discharge mechanism are housed within the powder storage device, eliminating any protruding parts, thereby reducing the storage space within the image forming device.

[0006] However, in the vertical powder storage device described above, the horizontal dimension is small, which limits the length of the horizontal transport path provided inside the powder storage device. In order to stabilize the flow rate of the developer transported by the transport screw, it is sufficient to make the transport path longer than a certain length. However, this makes the supply port for feeding the developer into the transport path smaller, making it difficult to supply a sufficient amount of developer into the transport path, resulting in a problem of reducing the amount of developer supplied to the developing device.

[0007] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a powder storage device that stabilizes the flow rate of developer supplied to a developing device while preventing the amount of developer supplied from becoming too small, and an image forming apparatus equipped with such a powder storage device. [Means for solving the problem]

[0008] A powder storage device according to one aspect of the present disclosure comprises a housing having an internal space and an outlet located below the internal space, a conveying screw that transports powder from one axial side to the other axial side and has a portion located above the outlet, and a wall that covers the conveying screw from the outside in the radial direction and divides the internal space into a storage chamber in which the powder is stored and a conveying path that houses the conveying screw and communicates with the storage chamber via an opening on one side and communicates with the outlet on the other side, and has a notch formed on one side in the axial direction from the area where the outlet is formed. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is an external view of an image forming apparatus according to the present disclosure. [Figure 2] 1 is a schematic cross-sectional view showing an internal structure of an image forming apparatus according to the present disclosure. [Figure 3] FIG. 2 is a perspective view showing an external structure of a developer accommodating device according to the present disclosure. [Figure 4] FIG. 2 is a perspective view showing an external structure of a developer accommodating device according to the present disclosure. [Figure 5] FIG. 2 is a perspective view showing an external structure of a developer accommodating device according to the present disclosure. [Figure 6] FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. [Figure 7] FIG. 7 is an enlarged cross-sectional view of a part of FIG. 6. [Figure 8] FIG. 7 is an enlarged cross-sectional view of a part of FIG. 6. [Figure 9] FIG. 9 is a cross-sectional view taken along line IX-IX of FIG. 8. [Figure 10] FIG. 9 is a cross-sectional view taken along the line XX in FIG. 8. [Figure 11]FIG. 10 is a cross-sectional view taken along the line XI-XI in FIG. 9. [Figure 12] FIG. 12 is an enlarged cross-sectional view of a part of FIG. [Figure 13] FIG. 3 is a cross-sectional view taken along the line XIII-XIII in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, identical or equivalent elements are designated by the same reference numerals, and redundant explanations will be omitted. Furthermore, the embodiments described below do not unduly limit the content of the present disclosure described in the claims, and not all of the configurations described in the embodiments are necessarily essential as means for solving the problems of the present disclosure.

[0011] <Image forming device> FIG. 1 is an external view of an image forming apparatus 100 according to the present disclosure. FIG. 2 is a schematic cross-sectional view showing the internal structure of the image forming apparatus 100 of FIG. 1. In the following description, the positional relationship of each component will be shown based on FIGS. 1 and 2. For example, in FIGS. 1 and 2, the upper surface will be referred to as the upper surface, the lower surface will be referred to as the lower surface, and the surface along the vertical direction will be referred to as the side surface. Furthermore, since the image forming apparatus 100 is usually installed on a horizontal surface, the left-right and depth directions in FIGS. 1 and 2 will also be referred to as the horizontal direction.

[0012] The image forming apparatus 100 is, for example, a printing machine having a printer function, which forms a multicolor or monochrome image on printing paper by electrophotography. Note that the image forming apparatus 100 of the present disclosure is not limited to a printing machine, but may also be a multifunction machine having a copying function, a printer function, a scanner function, a facsimile function, etc. The image forming apparatus 100 includes, for example, an apparatus main body 101 including a housing that houses each of the components that make up the image forming apparatus 100.

[0013] The apparatus main body 101 includes a photosensitive member 102, an exposure device 103, a developing device 104, an intermediate transfer unit 105, a secondary transfer roller 106, a fixing unit 107, a paper feed tray 108, a paper discharge tray 109, a developer container 200, and the like.

[0014] The photoreceptor 102 comprises a cylindrical conductive substrate and a photosensitive layer provided on the circumferential surface of the substrate. The photosensitive layer is insulating when not irradiated with light, and is conductive in areas irradiated with light. The surface of the photosensitive layer is charged to a predetermined potential. The photoreceptor 102 has a rotating shaft (not shown) along its axis, and is rotated around the rotating shaft by an electric motor (not shown).

[0015] The exposure device 103 irradiates light to expose the surface of the photosensitive layer of the photoreceptor 102. The exposure device 103 irradiates the photosensitive layer of the photoreceptor 102 with light to form an image based on image data to be printed. The charged photosensitive layer is exposed to the light irradiated by the exposure device 103, and an electrostatic latent image corresponding to the image data is formed on the surface of the photosensitive layer of the photoreceptor 102.

[0016] The developer accommodating device 200 is a container that accommodates developer and supplies the developer to the developing device 104 as needed. Examples of the developer include a two-component developer primarily composed of toner and carrier, and a single-component developer primarily composed of toner. The developer accommodating device 200 has an internal space capable of accommodating the developer, and may be box-shaped, cylindrical, or have any other suitable shape. The developer accommodating device 200 is detachably attached to the device main body 101. When the accommodated developer runs out, the user can replace it with a new developer accommodating device 200. The replaceable developer accommodating device 200 is also referred to as a toner cartridge, for example. As can be seen from FIGS. 1 and 2, the developer accommodating device 200 is located on the near side in the depth direction relative to the photoconductor 102, exposure device 103, developing device 104, etc., and is indicated by a dotted outline in FIG. 2. The detailed structure of the developer accommodating device 200 will be described later. The developer accommodating device 200 is an example of a powder accommodating device, and the developer accommodated in the developer accommodating device 200 is an example of a powder accommodated in a powder accommodating device. The powder accommodated in the powder accommodating device may be toner alone.

[0017] The developing device 104 supplies developer to the surface of the photosensitive layer of the photoreceptor 102 and develops the electrostatic latent image on the surface of the photoreceptor layer to form a toner image. The present disclosure exemplifies an image forming apparatus 100 capable of printing full-color images, which are achieved by overlaying monochrome images corresponding to four colors: cyan, magenta, yellow, and black. Therefore, the image forming apparatus 100 of the present disclosure includes four photoreceptors 102, four exposure devices 103, four developer storage devices 200, and four developing devices 104, one for each of the four colors. For example, each of the four photoreceptors 102, four exposure devices 103, and four developing devices 104 has substantially the same structure, and only the color of the toner supplied by the developing devices 104 to the photoreceptor 102 is different. Furthermore, since the consumption of black developer is generally greater than the consumption of the developers of the other three colors, the size of the developer storage device 200 that stores black developer may be made larger than the size of the developer storage device 200 that stores the developers of the other three colors to increase the amount of black developer that can be stored. Although not illustrated in the present disclosure, an image forming apparatus that prints only monochrome images differs from a full-color image forming apparatus in that it is composed only of a photoconductor, exposure device, developer storage device, and developing device that correspond to black.

[0018] The intermediate transfer unit 105 is disposed above the four photoconductors 102. The intermediate transfer unit 105 is an integrated unit that includes four intermediate transfer rollers corresponding to the four photoconductors 102, an intermediate transfer belt onto which the toner images on the photoconductors 102 are transferred by the intermediate transfer rollers, a drive roller and a tension roller that stretch and rotate the intermediate transfer belt, etc. The intermediate transfer rollers are each axially supported by the intermediate transfer unit 105 so that they rotate in response to the rotation of the intermediate transfer belt.

[0019] When a current is supplied to the intermediate transfer roller, a transfer electric field is formed between the photoreceptor 102 and the intermediate transfer belt at the position of the intermediate transfer roller. The action of the transfer electric field causes the toner image developed on the circumferential surface of the photoreceptor 102 to be transferred onto the intermediate transfer belt. Toner images corresponding to each of the four colors, cyan, magenta, yellow, and black, are sequentially transferred and superimposed onto the intermediate transfer belt by each of the four intermediate transfer rollers, forming a full-color toner image on the intermediate transfer belt.

[0020] The secondary transfer roller 106 is a member that transfers the toner image onto the print paper, and is arranged, for example, so as to contact the intermediate transfer belt of the intermediate transfer unit 105. The print paper supplied from the paper feed tray 108 is transported by multiple rollers and passes between the secondary transfer roller 106 and the intermediate transfer belt. As the print paper passes between the secondary transfer roller 106 and the intermediate transfer belt, the toner image formed on the intermediate transfer belt is transferred to one side of the print paper. The toner image transferred to the print paper is heated and pressed by a fixing unit 107, which includes a heating roller, a pressure roller, etc., to be fixed to the print paper. In this way, the image forming apparatus 100 completes printing of an image onto the print paper based on image data. The printed print paper is discharged to the paper output tray 109.

[0021] The image forming apparatus 100 is controlled by a control unit (not shown). The control unit is composed of a microcontroller and peripheral circuits. The microcontroller has a processor and memory. The processor executes a control program stored in the memory to operate the microcontroller and peripheral circuits as a control unit. All or part of the processing performed by the microcontroller may be performed by a dedicated electronic circuit. The control unit has a communication unit and the like that receives data, signals, etc. from the outside. In response to input operations by a user, reception of data from the outside, etc., the control unit transmits various data such as images, control signals, etc. to each unit and each device of the image forming apparatus 100, causing the image forming apparatus 100 to perform various operations.

[0022] <Developer storage device> The detailed structure of the developer accommodating device 200 of the present disclosure will be described with reference to Figures 3 to 12. Figures 3 to 5 are diagrams showing the external structure of the developer accommodating device 200, and Figures 6 to 12 are diagrams showing the internal structure of the developer accommodating device 200.

[0023] <Outline of the external structure of the developer storage device> Fig. 3 is an external view of the developer accommodating device 200 shown in Fig. 2 as viewed from diagonally above left. Fig. 4 is an external view of the developer accommodating device 200 shown in Fig. 2 as viewed from diagonally below left. Fig. 5 is an external view of the developer accommodating device 200 shown in Fig. 2 as viewed from diagonally above with the far left corner facing forward.

[0024] 3 and 4, the developer accommodating device 200 has a housing 201 having a discharge port 243 on the lower side. As will be described in detail later, the discharge port 243 communicates with an internal space 230 of the housing 201. In other words, the internal space 230 of the housing 201 is connected to the outside via the discharge port 243.

[0025] As will be described in detail later, a conveying screw 300 is provided in the internal space 230 of the housing 201. As shown in Fig. 5, a connecting portion for rotatably connecting to the conveying screw 300 is provided on the side of the housing 201. This connecting portion is connected to an electric motor (not shown) provided inside the device main body 101, and the conveying screw 300 is rotated by the electric motor.

[0026] <Details of the internal structure of the developer storage device> The internal structure of the developer accommodating device 200 will be described below with reference to Figures 6 to 12. Figures 6, 7, and 8 are cross-sectional views taken along line VI-VI in Figure 3, and show the internal structure of the developer accommodating device 200. More specifically, Figure 6 is a view of the developer accommodating device 200 shown in Figure 2 as viewed from diagonally above left, Figure 7 is an enlarged view of a portion of the developer accommodating device 200 in Figure 6 as viewed from diagonally above right, and Figure 8 is an enlarged view of a portion of the developer accommodating device 200 in Figure 6 as viewed from the front.

[0027] 9 is a cross-sectional view taken along line IX-IX in FIG. 8, and FIG. 10 is a cross-sectional view taken along line XX in FIG. 8. Both FIG. 9 and FIG. 10 are views of the developer accommodating device 200 as viewed from above. FIG. 11 is a cross-sectional view taken along line XI-XI in FIG. 9, and FIG. 12 is a cross-sectional view of an enlarged portion of FIG. 11. FIG. 11 is a view of the developer accommodating device 200 as viewed from diagonally above left, and FIG. 12 is a view of the developer accommodating device 200 as viewed from the left.

[0028] 6 to 8, the developer accommodating device 200 includes a housing 201 having a discharge port 243 formed on the bottom side. The housing 201 is box-shaped, and an internal space 230 is formed therein. More specifically, for example, the housing 201 is rectangular tubular, and is constructed of approximately six structural members consisting of a ceiling and a bottom disposed above and below, and four standing members provided between the ceiling and the bottom. The space surrounded by these structural members forms the internal space 230.

[0029] The internal space 230 has a portion at the bottom of the housing 201 that is partially recessed downward, and a conveying screw 300 is installed in the recessed portion. The conveying screw 300 has a structure in which a spiral blade 302 is fixed to the circumferential surface of a rotatably installed rotating shaft 301, and the axial direction of the rotating shaft 301 is installed parallel to the horizontal direction. The conveying screw 300 is installed, for example, with the rotating shaft 301 extending in the depth direction in Figures 6 and 7. Hereinafter, the direction in which the rotating shaft 301 extends is also referred to as the axial direction.

[0030] 6 to 8, a wall 240 is provided so as to cover the conveying screw 300 from the radial outside. The wall 240 is provided so as to extend along the axial direction, and divides the internal space 230 into a conveying path 232, which is the space in which the conveying screw 300 is accommodated, and an accommodation chamber 231, which is the other space.

[0031] <Containment Room> The storage chamber 231 is a space in which the developer is stored. An agitation unit 400, which is a rotatably mounted plate-like member, is provided inside the storage chamber 231. The agitation unit 400 can agitate and move the developer inside the storage chamber 231. For example, the agitation unit moves the developer on the storage chamber bottom 221, which is the lower surface of the storage chamber 231, and moves it onto the transport path 232. Note that, for the purpose of explaining the internal structure of the developer storage device 200, the developer present in the internal space 230 including the storage chamber 231 is not shown in the figure.

[0032] <Transport path> The conveying path 232 is a space that accommodates the conveying screw 300. For example, as shown in FIGS. 6 to 8 , the conveying path 232 is a passage-like space extending along the rotation axis 301 and surrounded by a wall 240 located above the radially outer side of the conveying screw 300 and a housing 201 located to the sides and below the radially outer side of the conveying screw 300 and in the axial direction. More specifically, as shown in FIGS. 7 , 9 , and 10 , the conveying screw 300 is installed in a direction in which the rotation axis 300 intersects at a right angle with two opposing upright portions of the structural members that constitute the housing 201 in a plan view. Each of the two opposing upright portions is provided with a bearing structure that supports the rotation axis 301. One bearing structure supports a first end 303 of the conveying screw 300 on one axial side, and the other bearing structure supports a second end 304 of the conveying screw 300 on the other axial side, thereby rotatably supporting the conveying screw 300. 5 and 10, the second end 304 is provided on the outer side surface of the housing 201 and is connected to a coupling part that rotates together with the rotating shaft 300. The rotating shaft 300 is connected to an electric motor provided inside the device main body 101 via the coupling part and can rotate. A transport path 232 is formed between the first end 303 and the second end 304. In FIG. 10, the position of the wall 240 is indicated by a dotted outline.

[0033] A conveying path 232 is formed between a first end 303 on one axial side of the conveying screw 300 and a second end 304 on the other axial side. In Figure 10, the position of the wall 240 is indicated by a dotted outline.

[0034] In the following description, the side of the first end 303 will be referred to as one axial side, and the side of the second end 304 will also be referred to as the other axial side. In the present disclosure, as shown in Fig. 7, the conveying screw 300 is adjacent to the inner surface 220, which is the surface facing the internal space 230, at one of the erected portions that are structural members of the housing 201 in the axial direction, and is installed along the inner surface 220, but may also be installed at a position away from the inner surface 220, for example.

[0035] The wall 240 has an opening 241 on the side of the first end 303, and the storage chamber 231 and the conveying path 232 communicate with each other via the opening 241. As shown in Figures 9 and 10, the first end 303 of the rotating shaft 301 protrudes to one side in the axial direction beyond the opening 241 in a plan view, and projects outside the conveying path 232 to be received by a bearing structure.

[0036] The developer moved onto the conveying path 232 by the agitation unit 400 moves through the opening 241 into the inside of the conveying path 232. The conveying screw 300 conveys the developer from a first end 303, which is one side in the axial direction, to a second end 304, which is the other side in the axial direction, while agitating the developer that has moved into the inside of the conveying path 232 by rotation.

[0037] As shown in FIGS. 9 and 10 , a discharge port 243 is provided at the bottom of the transport path 232 on the side of the second end 304. As can be seen from FIGS. 4 , 11 , and 12 , the transport path 232 communicates with the outside of the developer accommodating device 200 via the discharge port 243. The second end 304 of the rotating shaft 301 protrudes further axially than the discharge port 243 in a plan view, protruding outside the transport path 232 and being received by a bearing structure. The developer transported to the side of the second end 304 by the transport screw 300 is discharged from the discharge port 243 to the outside of the developer accommodating device 200. The amount of developer transported by the transport screw 300 is regulated by the size of the cross-section of the transport path 232, so that the amount of developer discharged from the discharge port 243 can be stabilized.

[0038] 8, it is preferable that the cross section of the transport path 232 is circular and has the same size as the maximum diameter of the spiral blade 302 of the transport screw 300. This allows all of the developer that has entered the transport path 232 to be transported by the transport screw 300, thereby reducing the amount of developer remaining in the transport path 232.

[0039] <Developing device and developer storage device> Fig. 13 is a cross-sectional view taken along the line XIII-XIII in Fig. 2. Of the components of the image forming apparatus 100, Fig. 13 shows only a part of the developing device 104 and the developer accommodating device 200.

[0040] 13, the developer discharged from the developer accommodating device 200 is supplied to the developing device 104 through the path indicated by the dotted arrow. More specifically, when the image forming apparatus 100 is attached to the developer accommodating device 200, the discharge port 243 and the developer supply port 601 of the developing device 104 join together to form a passage. The developer discharged from the discharge port 243 is supplied from the developer supply port 601 into the inside of the conveying path 600 of the developing device, and is conveyed into the inside of the developing device 104 by the conveying screw 602 of the developing device. In this way, the developer in the developing device 104 that has been consumed by printing by the image forming apparatus 100 can be supplied from the developer accommodating device 200.

[0041] 3, 4, 5, and 9, the conveying screw 300 and the conveying path 232 are housed inside the housing 201 and are not configured to partially protrude from the housing 201. This makes it possible to realize the developer accommodating device 200 that is easy to incorporate inside the image forming apparatus 100 and is suitable for saving space, even when the image forming apparatus 100 is made compact and there is little room for accommodation.

[0042] <Detailed wall structure> As shown in FIGS. 7 and 9 , the wall 240 has a notch 242 formed on one side in the axial direction from the first region 501 where the discharge port 243 is formed on the other side in the axial direction. In other words, as shown in FIGS. 9 and 10 , the wall 240 has a partially cut-out portion along the axial and circumferential directions of the conveying screw 300 in a portion closer to the opening 241 than the region overlapping with the discharge port 243 in a plan view. In order to stabilize the amount of developer discharged from the discharge port 243, it is preferable that the wall 240 excluding the opening 241 is as long in the axial direction as possible from the viewpoint of regulating the amount of developer conveyed by the size of the conveying path 232. However, when the length of the conveying path 232 is limited by the dimensions of the housing 201, it is necessary to make the opening 241 small to make the wall 240 as long as possible. However, making the opening 241 small causes a problem in that the amount of developer entering the conveying path 232 from the containing chamber 231 is reduced. In the present disclosure, by providing the notch 242 in the wall 240, developer can be introduced into the transport path 232 from the notch 242 in addition to the opening 241, thereby realizing a space-saving developer accommodating device 200 while increasing the amount of developer discharged from the discharge port 243. Furthermore, the partial presence of the wall 240 in the area where the notch 242 is present also has the effect of regulating the amount of developer transported by the size of the transport path 232, and therefore the stability of the amount of developer discharged from the discharge port 243 can be maintained.

[0043] In the axial direction of the conveying screw 300, the notch 242 is within the range in which the conveying screw 300 exists in a plan view. Therefore, the conveying screw 300 can be seen through the notch 242 from the radially outer side of the conveying screw 300. As a result, the developer that enters through the notch 242 enters a position in the conveying screw 300, and can be conveyed efficiently.

[0044] 8, it is sufficient if the height of the upper surface of wall 240 and the height of storage chamber bottom 221, which is the lower surface of storage chamber 231, are similar to some extent, but it is more preferable to make the height of the upper surface of wall 240 lower than the height of storage chamber bottom 221. This makes it easier for the developer at storage chamber bottom 221 to move onto wall 240, and the amount of developer that enters conveying path 232 from notch 242 can be increased.

[0045] 9, the wall 240 may have a notch 242 formed in the axial direction from the first region 501, in which the discharge port 243 is formed, to the opening 241. When the opening 241 and the notch 242 are continuous openings, the developer can easily enter the inside of the transport path 232, and the amount of developer that enters the transport path 232 from the storage chamber 231 can be increased. Note that in the present disclosure, the notch 242 does not need to be continuous with the opening 241, and may be, for example, a hole that is partially opened in the wall 240. Furthermore, the number of notches 242 may be one or more.

[0046] 9, it is more preferable that the wall 240 has the notch 242 formed only on one side in the axial direction, rather than on the first region 501 in which the discharge port 243 is formed in the axial direction. If the notch 242 is provided in the wall 240 in a region that overlaps with the first region 501 in which the discharge port 243 is formed in a plan view, the developer that enters the inside of the conveying path 232 through the notch 242 may be discharged directly from the discharge port 243 without being conveyed by the conveying screw 300, which may cause the amount of developer to become unstable. Therefore, it is more preferable to provide the notch 242 in a position that does not overlap with the first region 501 in a plan view, from the viewpoint of maintaining the stability of the amount of developer discharged from the discharge port 243.

[0047] The rotation shaft 301 of the conveying screw 300 rotates in a predetermined first direction corresponding to the direction in which the developer is conveyed from the opening 241 toward the discharge port 243. For example, in the present disclosure, as shown in FIG. 8 , the first direction, which is the rotation direction of the rotation shaft 301 of the conveying screw 300, is counterclockwise. In this case, as shown in FIG. 9 , the wall 240 preferably has a notch 242 formed in a second region 502 that is downstream of the rotation around the first direction, based on an imaginary line 500 on which the rotation shaft 301 is projected. In the second region 502, the spiral blade 302 moves in the radial direction of the conveying screw 300 toward the structure of the housing 201 that constitutes the conveying path 232. Therefore, the developer that enters through the notch 242 is smoothly taken into the conveying path 232 by the spiral blade 302, making it easier for the developer to enter the conveying path 232, thereby increasing the amount of developer that enters the conveying path 232 from the storage chamber 231.

[0048] As shown in FIG. 7 , the housing 201 has an inner surface 220 on the side facing the internal space 230, for example, in a vertically erected portion of a structural member constituting the housing 201. The conveying screw 300 is disposed adjacent to the inner surface 220 in the axial direction and along the inner surface 220. In this case, as shown in FIGS. 7 and 9 , the wall 240 preferably has a notch 242 formed in a third region 503 on the side closer to the inner surface 220, with reference to an imaginary line 500 onto which the rotation axis is projected. Developer attempting to enter the conveying path 232 through the notch 242 may be returned to the outside of the conveying path 232 by the spiral blade 302 depending on the timing of the rotation of the conveying screw 300. However, even in such a case, the developer hits the inner surface 220, falls downward, and can re-enter the conveying path 232 through the notch 242 below. This allows the developer to easily enter the inside of the transport path 232, and the amount of developer that enters the transport path 232 from the storage chamber 231 can be increased.

[0049] As shown in FIGS. 10 and 12 , the conveying screw 300 has a helical blade 302 fixed to the circumferential surface of the rotating shaft 301 at a constant pitch of length Ls. In this case, it is preferable that the axial length Lw of the wall 240, excluding the opening 241, is equal to or greater than the length Ls of one pitch of the helical blade 302. In order to regulate the amount of developer conveyed by the conveying screw 300 by the size of the conveying path 232 and stabilize the amount of developer conveyed, it is preferable that the developer make one or more revolutions around the rotating shaft 301 while being conveyed while the conveying path 232 is regulated by the size of the conveying path 232. When the developer is conveyed by the conveying screw 300 in the axial direction a distance Ls, which is the length of one pitch of the helical blade 302, it makes one revolution around the rotating shaft 301. Therefore, if the axial length Lw of the wall 240, including the portion where the notch 242 is formed, is equal to or greater than the length Ls of one pitch of the helical blade 302, the amount of developer conveyed can be more stabilized.

[0050] The present disclosure is not limited to the configurations of the above-described embodiments and modified examples, and may be replaced with a configuration that is substantially the same as the configurations shown in the above-described embodiments and modified examples, a configuration that has the same effect, or a configuration that can achieve the same purpose. [Explanation of symbols]

[0051] 100: Image forming device 101: Device body 102: Photoreceptor 103: Exposure equipment 104: Developing device 105: Intermediate transfer unit 106: Secondary transfer roller 107: Fuser unit 108: Paper tray 109: Paper output tray 200: Developer storage device 201: Cabinet 220:Inside 221: Bottom of containment chamber 230:Interior space 231: Containment Room 232: Transport path 240: Wall 241:Aperture 242: Notch 243: Outlet 300: Conveying screw 301: Rotating shaft 302: Spiral blade 303: First end 304:Second end 400: Mixing unit 500: Virtual line projected onto the rotation axis 501:First area 502:Second area 503: Third area 600: Developing device transport path 601: Developer supply port 602: Developing device conveying screw

Claims

1. a housing having an internal space and an outlet located below the internal space; a conveying screw that conveys the powder from one side in an axial direction to the other side in the axial direction and has a portion that is positioned above the discharge port; a wall covering the conveying screw from the radially outer side, dividing the internal space into a storage chamber in which the powder is stored and a conveying path in which the conveying screw is stored, communicating with the storage chamber via an opening on the one side and communicating with the discharge port on the other side, the wall having a notch formed on the one side from a region in which the discharge port is formed in the axial direction; A powder containing device comprising:

2. The powder containing device according to claim 1 , wherein the wall has the notch formed therein in the axial direction from a region in which the discharge port is formed to the opening.

3. The powder containing device according to claim 2 , wherein the wall has the notch formed only on the one side of a region where the discharge port is formed in the axial direction.

4. the conveying screw has a rotation axis that rotates around a first direction, 2 . The powder containing device according to claim 1 , wherein the notch is formed in the wall in a region downstream of a virtual line onto which the rotation axis is projected in the first direction.

5. the housing has an inner surface; the conveying screw has a rotation axis and is disposed adjacent to and along the inner surface in the axial direction; The powder containing device according to claim 1 , wherein the wall has the notch formed in a region closer to the inner surface with respect to an imaginary line onto which the rotation axis is projected.

6. The conveying screw has spiral blades fixed at a constant pitch to the circumferential surface of a rotating shaft, 2. The powder containing device according to claim 1, wherein the length of the wall in the axial direction excluding the opening is equal to or greater than one pitch of the spiral blade.

7. The powder containing device according to claim 1 ; a developing device to which the powder discharged from the discharge port is supplied.

Images