Developing unit and image formation device

Abstract

To suppress a decrease in the amount of developer used compared to when a developer continues to remain in a space between structural members.SOLUTION: Provided is a developing unit comprising: a developer holding body 334 that holds a developer, which contains toner and carrier, to be supplied to an image holding body that forms an electrostatic latent image; a specifying member that specifies the amount of developer held by the developer holding body 334 to be a specified amount; and a member 60 disposed to reduce a space below the specifying member and also disposed in an area 64 which is less likely to bend compared to another area 66 in the specifying member in the axial direction of the developer holding body 334.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a developing unit and an image forming apparatus. [Background technology]

[0002] For example, Patent Document 1 discloses a developing device having a transport member that rotates to transport developer, a developing means that develops an electrostatic latent image on an image carrier, a rotating member that rotates in a circumferential direction, a supply means that magnetically attracts the developer transported by the transport member and releases the attracted developer from the rotating member to supply it to the developing means, and a variable mechanism that varies the amount of developer supplied from the supply means to the developing means. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-173336 A Summary of the Invention [Problem to be solved by the invention]

[0004] Here, in a developing unit that has as its components at least a developer carrier that holds developer and a regulating member that regulates the amount of developer on the developer carrier, if the developer regulated by the regulating member remains in the space between the components, the amount of developer used will decrease. An object of the present invention is to suppress the decrease in the amount of developer used, compared to the case where the developer continues to remain in the spaces between the components. [Means for solving the problem]

[0005] The invention described in claim 1 is a developing unit comprising: a developer holder for holding a developer containing toner and a carrier, the developer being supplied to an image holder that forms an electrostatic latent image; a regulating member for regulating the developer held in the developer holder to a specified amount; and a member arranged to reduce the space below the regulating member, the member being arranged in an area of ​​the regulating member that is less likely to bend in the axial direction of the developer holder than other areas. The invention described in claim 2 is the developing unit described in claim 1, characterized in that the region less likely to bend is provided in a region excluding a middle portion in the axial direction of the developer carrier. The invention described in claim 3 is the developing unit described in claim 2, characterized in that the area excluding the intermediate portion is both end portions in the axial direction. The invention recited in claim 4 is the developing unit recited in claim 1, characterized in that the surface of the member facing the regulating member is defined by a positional relationship with the developer carrier. The invention recited in claim 5 is the developing unit recited in claim 4, characterized in that the positional relationship is such that the distance to the developer carrier does not change even when moving downward. The invention recited in claim 6 is the developing unit recited in claim 4, characterized in that the positional relationship is such that the distance to the developer carrier increases toward the bottom. The invention described in claim 7 is the developing device described in claim 1, characterized in that a member other than the member in question is provided in an area where the member is not provided, and the cross-sectional area of ​​the other member is smaller than the cross-sectional area of ​​the member. The invention described in claim 8 is the developing device described in claim 1, characterized in that a member other than the member in question is provided in an area where the member is not provided, and the cross-sectional area of ​​the member is smaller at an end closer to the other member in the axial direction than at an end farther from the other member. The invention recited in claim 9 is the developing device recited in claim 7 or 8, characterized in that the separate member has a cross-sectional area that decreases from the end portion to the center of the separate member. The invention described in claim 10 is an image forming apparatus including an image holder that forms an electrostatic latent image, a developing means that develops the electrostatic latent image formed on the image holder into a toner image, a transfer means that transfers the toner image by the developing means onto a recording material, and a fixing means that fixes the toner image transferred onto the recording material to the recording material, wherein the developing means is a developer holder that holds a developer containing toner and a carrier and is supplied to the image holder that forms an electrostatic latent image, a regulating member that regulates the developer held in the developer holder to a specified amount, and a member that is arranged to reduce the space below the regulating member and is arranged in an area of ​​the regulating member that is less likely to bend in the axial direction of the developer holder than other areas. Effect of the Invention

[0006] According to the invention of claim 1, it is possible to suppress a decrease in the amount of developer used, compared to a case where the developer continues to remain in the spaces between the component members. According to the invention of claim 2, the amount of developer that falls from the space below the regulating member can be increased compared to a case in which the area that is less likely to bend is not provided in an area excluding the middle part in the axial direction of the developer holder. According to the invention of claim 3, the area excluding the intermediate portion can suppress a decrease in the amount of developer used, compared to a case where the area does not include both ends in the axial direction. According to the invention of claim 4, the member can reduce the amount of developer remaining in the space below the regulating member compared to a case in which the member does not have a configuration in which the surface facing the regulating member is determined by its positional relationship with the developer carrier. According to the invention of claim 5, the positional relationship is such that the distance to the developer carrier remains the same even when moving downward, and compared to a case in which the configuration is not provided, the space below the regulating member can be made narrower. According to the invention of claim 6, the positional relationship is such that the distance from the developer holder increases as it goes downward, making it easier for the developer to fall from the space below the regulating member compared to a case in which the configuration is not provided. According to the invention of claim 7, a member other than the member is provided in an area where no member is provided, and the cross-sectional area of ​​the other member is smaller than the cross-sectional area of ​​the member, thereby suppressing a reduction in the amount of developer used compared to a case where the configuration is not provided. According to the invention of claim 8, a component other than the component is provided in an area where no component is provided, and the cross-sectional area of ​​the component is smaller at the end closer to the other component in the axial direction than at the end farther from the other component, the reduction in the amount of developer used can be suppressed compared to a case where the component does not have a configuration in which the cross-sectional area of ​​the component is smaller at the end closer to the other component in the axial direction than at the end farther from the other component. According to the invention of claim 9, the another member can suppress a decrease in the amount of developer used, compared to a case in which the another member does not have a configuration in which the cross-sectional area decreases from the end to the center of the another member. According to the invention of claim 10, it is possible to suppress a decrease in the amount of developer used, compared to a case where the developer continues to remain in the spaces between the component members. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating an image forming apparatus. [Diagram 2] 1A and 1B are diagrams illustrating a developing device of an image forming apparatus, in which FIG. 1A shows a first configuration example and FIG. 1B shows a second configuration example. [Diagram 3] FIG. 2 is a perspective view illustrating a more specific configuration of a developing unit according to the first configuration example. [Figure 4] FIG. 2 is a perspective view illustrating a more specific configuration of a developing unit according to the first configuration example. [Diagram 5] 5A and 5B are longitudinal cross-sectional views for explaining various shapes of the restricting member in the first configuration example, where (a) shows a first shape example and (b) shows a second shape example. [Figure 6] 5A and 5B are longitudinal cross-sectional views for explaining various shapes of the limiting member in the first configuration example, where (a) shows a third shape example and (b) shows a fourth shape example. [Figure 7] 6A to 6C are perspective views illustrating another configuration of the limiting portion, in which (a) to (c) show the limiting member. [Figure 8]1 is a graph illustrating block size according to axial position, with the vertical axis representing block size and the horizontal axis representing axial position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a diagram illustrating an image forming apparatus 1. As shown in FIG. The image forming apparatus 1 according to this embodiment includes a paper feed unit 1A, a printing unit 1B, and a paper discharge unit 1C. The paper feed unit 1A includes a first paper storage section 11 to a fourth paper storage section 14 for storing paper P as an example of a recording medium. The paper feed unit 1A also has feed rolls 15-18 that correspond to the first paper storage section 11 to the fourth paper storage section 14, respectively, and feed the paper P stored in each paper storage section to a transport path connected to the printing unit 1B.

[0009] The printing unit 1B includes an image forming section 20 that forms an image on a sheet P. The printing unit 1B also includes a control section 21 that controls each section of the image forming apparatus 1. The printing unit 1B also includes an image processing section 22. The image processing section 22 performs image processing on image data transmitted from the image reading device 4 and the personal computer (PC) 5. The printing unit 1B is also provided with a UI (User Interface) 23, which is configured with a touch panel or the like and notifies the user of information and receives information input from the user.

[0010] Image forming section 20, as an example of an image forming means, is provided with six image forming units 30T, 30P, 30Y, 30M, 30C, and 30K (hereinafter, sometimes simply referred to as "image forming units 30") arranged in parallel at regular intervals. Each image forming unit 30 includes a photosensitive drum 31 on which an electrostatic latent image is formed while rotating in the direction of arrow A, a charging roll 32 which charges the surface of the photosensitive drum 31, a developing device 33 which develops the electrostatic latent image formed on the photosensitive drum 31, and a drum cleaner 34 which removes toner and the like from the surface of the photosensitive drum 31.

[0011] The image forming section 20 is also provided with a laser exposure device 26 that exposes the photoconductor drum 31 of each image forming unit 30 to laser light. The exposure of the photoconductor drum 31 by the laser exposure device 26 is not limited to using laser light. For example, a light source such as an LED (Light Emitting Diode) may be provided for each image forming unit 30, and the photoconductor drum 31 may be exposed to light emitted from the light source.

[0012] Each image forming unit 30 is configured similarly, except for the toner contained in the developer 33. The image forming units 30Y, 30M, 30C, and 30K form toner images of yellow (Y), magenta (M), cyan (C), and black (K), respectively. Further, the image forming units 30T and 30P form toner images using toner corresponding to a corporate color, foaming toner for Braille, fluorescent color toner, toner for improving gloss, etc. In other words, the image forming units 30T and 30P form toner images using toner of a special color.

[0013] The image forming section 20 is also provided with an intermediate transfer belt 41 onto which the toner images of each color formed on the photosensitive drums 31 of the image forming units 30 are transferred. The image forming section 20 is also provided with a primary transfer roll 42 that transfers the respective color toner images of the respective image forming units 30 onto the intermediate transfer belt 41 at a primary transfer portion T1. The image forming unit 20 is also provided with a secondary transfer roll 40 that transfers the toner image transferred onto the intermediate transfer belt 41 onto the paper P at a secondary transfer portion T2. Furthermore, the image forming section 20 is provided with a belt cleaner 45 that removes toner and the like from the surface of the intermediate transfer belt 41, and a fixing device 80 that fixes the secondarily transferred image onto the paper P.

[0014] The image forming unit 20 performs an image forming operation based on a control signal from the control unit 21 . Specifically, in the image forming unit 20, first, image processing is performed on the image data input from the image reading device 4 or the PC 5 by the image processing unit 22, and the image data after image processing is supplied to the laser exposure device 26. Then, for example, in a magenta (M) image forming unit 30M, the surface of the photosensitive drum 31 is charged by the charging roll 32, and then the laser exposure device 26 irradiates the photosensitive drum 31 with laser light modulated by image data obtained from the image processing unit 22.

[0015] As a result, an electrostatic latent image is formed on the photoconductor drum 31 . The formed electrostatic latent image is developed by the developing unit 33, and a magenta toner image is formed on the photosensitive drum 31. Similarly, yellow, cyan and black toner images are formed in the image forming units 30Y, 30C and 30K, and special color toner images are formed in the image forming units 30T and 30P.

[0016] The respective color toner images formed in each image forming unit 30 are electrostatically transferred sequentially by a primary transfer roll 42 onto an intermediate transfer belt 41 rotating in the direction of arrow C in Figure 1, and superimposed toner images are formed on the intermediate transfer belt 41. The superimposed toner image formed on the intermediate transfer belt 41 is transported to a secondary transfer portion T2 constituted by a secondary transfer roll 40 and a backup roll 49 as the intermediate transfer belt 41 moves.

[0017] On the other hand, the paper P is taken out from the first paper storage unit 11 by, for example, the delivery roll 15, and then transported to the position of the registration roll 74 via the transport path. When the superimposed toner image is transported to the secondary transfer portion T2, a sheet of paper P is supplied from the registration roll 74 to the secondary transfer portion T2 in accordance with the transport timing. Then, in the secondary transfer portion T2, the superimposed toner images are electrostatically transferred onto the paper P all at once by the action of a transfer electric field formed between the secondary transfer roll 40 and the backup roll 49.

[0018] Thereafter, the paper P onto which the superimposed toner images have been electrostatically transferred is transported to a fixing device 80. In the fixing device 80, pressure and heat are applied to the paper P on which the unfixed toner image has been formed, and the toner image is fixed to the paper P. Then, the sheet P on which the fixing process has been performed passes through a curl correction section 81 provided in the sheet discharge unit 1C, and is then conveyed to a sheet stacking section (not shown).

[0019] The photoconductor drum 31 is an example of an image carrier in the image forming apparatus, the developing device 33 is an example of a developing unit, the secondary transfer portion T2 is an example of a transferring unit, and the fixing device 80 is an example of a fixing unit.

[0020] 2A and 2B are diagrams for explaining the developing device 33 of the image forming apparatus 1, in which (a) shows a first configuration example and (b) shows a second configuration example. Note that the developing device 33 shown in FIG. 2 is shown as viewed from the rear side. 2A, the developing device 33 according to the first configuration example includes a container 331 that contains a developer therein. The container 331 is configured with a container housing 332 made of resin. The housing 332 of the developing unit 33 is arranged to extend along a direction perpendicular to the paper surface of FIG. 2, which is the direction from the front side to the rear side of the image forming apparatus 1 (see FIG. 1), and has a rear end (not shown) on the rear side and a front end (not shown) on the front side.

[0021] An opening 333 is provided in the housing 332 at a location facing the photoconductor drum 31 (see FIG. 1). A developing roll 334 that adheres a developer to the surface of the photoconductor drum 31 is provided in the opening 333. The developing roll 334 is formed in a cylindrical shape and is arranged so as to extend along a direction from the front side to the rear side of the image forming apparatus 1. In addition, the developing roll 334 is arranged so as to extend along the longitudinal direction of the developing unit 33.

[0022] The developing roll 334 is provided with a developing sleeve 334A that is formed of a cylindrical body and that is driven to rotate, and a magnet roll 334B that is disposed inside the developing sleeve 334A. The developing sleeve 334A is made of a metal such as SUS, etc. The developing sleeve 334A rotates in the direction of the arrow D in the figure.

[0023] Furthermore, in this embodiment, at the primary transfer portion T1 (see FIG. 1) between the developing roll 334 and the photosensitive drum 31, the developing sleeve 334A and the photosensitive drum 31 rotate so that they move in the same direction. The developing unit 33 is provided with a layer regulating member 335 that regulates the layer thickness of the developer held on the developing roll 334 .

[0024] As shown in FIG. 2, the developing device 33 is provided with a first transport member 336 and a second transport member 337 for transporting the developer. The first transport member 336 and the second transport member 337 are provided on the opposite side to the side on which the photoconductor drum 31 (see FIG. 1) is installed, with the developing roll 334 interposed therebetween. The first transport member 336 has a rotation axis aligned with the rotation axis of the developing sleeve 334A that is driven to rotate, and rotates around this rotation axis to transport the developer in the container 331.

[0025] In the developing device 33 configured in this manner, new toner or toner to which a very small amount of carrier has been added is circulated by being stirred and transported between the first transport member 336 and the second transport member 337. More specifically, by transferring the developer through connection ports formed at both ends of a partition wall extending in the axial direction, the developer stirred by the first transport member 336 is stirred by the second transport member 337, and can also be stirred by the first transport member 336. In the developing device 33, a circulation path is formed, which is a path that circulates in the axial direction by the rotation of each of the first transport member 336 and the second transport member 337.

[0026] The developing unit 33 is provided with a third transport member 338 adjacent to the second transport member 337. In addition, the developing unit 33 is provided with a pick-up roll 339 located above the third transport member 338. The developing device 33 is provided with a support member 51 located between the second transport member 337 and the pickup roll 339, and a layer regulating member 52 supported by the support member 51 and regulating the layer thickness of the developer held by the pickup roll 339. The layer regulating member 52 regulates the amount of developer held by the pickup roll 339 to a specified amount.

[0027] The developing unit 33 is provided with a limiting portion 60 that is supported by the supporting member 51 and positioned below the layer regulating member 52. The limiting portion 60 is provided so as to reduce the space S below the layer regulating member 52.

[0028] The transport path formed by the rotation of the third transport member 338 is connected to the circulation path described above, and receives the developer from the circulation path. The third transport member 338 supplies the developer to a pickup roll 339. The pickup roll 339 supplies the developer to the developing roll 334. For example, the first transport member 336 transports toward the front side of the paper, the second transport member 337 transports toward the back side of the paper, and the third transport member 338 transports toward the front side of the paper.

[0029] The developing roll 334, the layer regulating member 335, the first transport member 336, the second transport member 337, the third transport member 338, the pickup roll 339, the support member 51 and the layer regulating member 52 are arranged approximately parallel to the photosensitive drum 31 (see FIG. 1).

[0030] In the first configuration example, the pickup roll 339 holds the developer to be supplied to the developing roll 334 . The developing roll 334 is an example of an image carrier, the pickup roll 339 is an example of a developer carrier, the layer regulating member 52 is an example of a regulating member, and the limiting members 61 and 62 (see Figure 4) of the limiting section 60, which will be described later, are examples of members.

[0031] The second configuration example shown in FIG. 2(b) has a basic configuration in common with the first configuration example described above, so the same reference numerals are used for the common parts and their explanation may be omitted. The developing device 33 according to the second configuration example does not have the pickup roll 339 and the layer regulating member 335 provided in the first configuration example. In the second configuration example, the support member 51, the layer regulating member 52, and the limiting portion 60 are positioned between the developing roll 334 and the third transport member 338, differently from the first configuration example.

[0032] More specifically, in the second configuration example, the developing roll 334 of the developing device 33 holds the developer to be supplied to the photoconductor drum 31 (see FIG. 1). The layer regulating member 52 regulates the amount of developer held by the developing roll 334 to a specified amount. The photosensitive drum 31 is an example of an image carrier, the developing roll 334 is an example of a developer carrier, the layer regulating member 52 is an example of a regulating member, and the limiting members 61 and 62 (see Figure 4) of the limiting section 60, which will be described later, are examples of members.

[0033] Next, a more specific configuration of the developing unit 33 according to the first configuration example will be described. 3 and 4 are perspective views for explaining a more specific configuration of the developing device 33 according to the first configuration example, and show a state in which the pickup roll 339 located above the third transport member 338 has been removed. More specifically, FIG. 3 shows a state in which the layer regulating member 52 (see FIG. 2(a)) has been removed, and FIG. 4 shows a state in which the layer regulating member 52 has been attached. Note that in FIGS. 3 and 4, explanations of parts that are the same as those in FIG. 2 and have the same reference numerals may be omitted.

[0034] 3, the developing unit 33 includes an attachment member 53 attached to the lower surface of a support member 51. A limiting member 61 constituting a part of the limiting portion 60 is attached to the attachment member 53. That is, the support member 51 supports the limiting member 61 via the attachment member 53.

[0035] The limiting member 61 is disposed at an end 64 in the axial direction J of the pickup roll 339 (see, for example, FIG. 2(a)). The end 63 in the axial direction J referred to here refers to a position close to the plate-like member 54 that holds the developing roll 334 of the developing device 33 and the like, and is a region that is less likely to bend in the axial direction J than other regions other than the end 63, for example, the position of a central portion 66.

[0036] 3, the limiting member 61 is disposed at an end 64 in the axial direction J which is less likely to bend, but is not disposed at a central portion 66 which is more likely to bend. In other words, the limiting portion 60 is disposed in a region in the axial direction J excluding the central portion 66. The central portion 66 is an example of an intermediate portion, and the end portion 63 is an example of a region excluding the intermediate portion. The axial direction J is the same as the depth direction of the image forming apparatus 1 (the direction perpendicular to the paper surface of FIG. 1).

[0037] The restriction portion 60 will now be described in more detail. 4, the limiting portion 60 is composed of a limiting member 61 provided at the end 64 described above, and a limiting member 62 provided at the end 65. The limiting member 62 is provided at a position closer to the plate-shaped member 55.

[0038] In this manner, the layer regulating member 52 is provided over the end portions 64, 65 and the central portion 66, which are the entire section 67 sandwiched between the plate-like members 54, 55 arranged at a distance from each other. On the other hand, the limiting members 61, 62 of the limiting portion 60 are provided over the end portions 64, 65, which are the areas excluding the central portion 66.

[0039] Therefore, the developer restricted by the layer restricting member 52 remains in the space S (for example, see FIG. 2(a)) between the components, the second and third transport members 337 and 338, and the pickup roll 339, by the restricting portion 60. However, in this embodiment, focusing on the axial direction J, the restricting portion 60 is formed by the restricting member 61 provided at the end 64 and the restricting member 62 provided at the end 65, while no restricting member is provided at the center portion 66. Therefore, the restricted developer falls from the center portion 66 and is returned to the circulation path by the second and third transport members 337 and 338. Therefore, the amount of developer that cannot be used due to remaining in the space between the components is reduced, and thus the decrease in the amount of developer that can be supplied to the developing roll 334 is suppressed.

[0040] In this embodiment, the limiting members 61, 62 are provided at the ends 64, 65, which are both ends, but a member constituting part of the limiting portion 60 may be provided at one of the ends 64, 65. That is, the limiting member 61 may be provided at the end 64 but not at the end 65, or the limiting member 62 may be provided at the end 65 but not at the end 64.

[0041] Next, various shapes of the restricting members 61 and 62 will be described. Figures 5 and 6 are longitudinal cross-sectional views illustrating various shapes of the restricting members 61, 62 in the first configuration example, where (a) of Figure 5 is a first shape example, (b) is a second shape example, (a) of Figure 6 is a third shape example, and (b) is a fourth shape example. 5 and 6, the restricting member 61 and the restricting member 62 have the same shape, and will be described without distinguishing between them. Also, in the second configuration example (see FIG. 2(b)), the shape can be the same as in the first configuration example (see FIG. 2(a)), and therefore the description thereof will be omitted.

[0042] 5(a), when attached to the mounting member 53, the limiting members 61 and 62 according to the first shape example have, as surfaces facing the layer regulating member 52, a surface 63a located below the layer regulating member 52 and extending in the up-down direction V, a surface 63b connected to the lower end of surface 63a and inclined relative to surface 63a in a direction toward the third conveying member 338, and a surface 63c extending from the lower end of surface 63b in parallel to surface 63a. These surfaces 63a to 63c are formed continuously.

[0043] In the first shape example, the surfaces 63a to 63c of the limiting members 61, 62 are surfaces facing the layer regulating member 52, and are defined by a positional relationship with the pickup roll 339. More specifically, the surface 63b is defined in such a relationship that the distance to the pickup roll 339 remains the same even when going downward in the up-down direction V.

[0044] 5(b) according to the second shape example, when attached to the attachment member 53, the limiting members 61 and 62 have, as surfaces facing the layer regulating member 52, a surface 63d located below the layer regulating member 52 and extending laterally toward the pickup roll 339, and a surface 63e extending downward in the up-down direction V from an end of the surface 63d. The surfaces 63d to 63e are formed continuously.

[0045] In the second shape example, the surfaces 63a to 63c of the limiting members 61, 62 are surfaces facing the layer regulating member 52, and are defined by a positional relationship with the pickup roll 339. More specifically, the surface 63e is defined in such a relationship that the distance from the pickup roll 339 increases downward in the up-down direction V.

[0046] The limiting members 61, 62 relating to the third shape example shown in Figure 6(a) have, when attached to the mounting member 53, a surface 63f located below the layer regulating member 52 and extending in the vertical direction V from the upper end to the lower end, as the surface facing the layer regulating member 52. In the third shape example, similarly to the above-mentioned second shape example (see FIG. 5(b)), the surface 63f is defined in such a relationship that the distance from the pickup roll 339 increases downward in the up-down direction V.

[0047] 6(b), when attached to the mounting member 53, the limiting members 61 and 62 according to the fourth shape example have, as surfaces facing the layer regulating member 52, a surface 63g located below the layer regulating member 52 and extending obliquely upward toward the layer regulating member 52, a surface 63h extending downward from the upper end of surface 63g and having a gently convex arc shape toward the pickup roll 339, and a surface 63i extending from the lower end of surface 63h in a direction away from the pickup roll 339. These surfaces 63g to 63i are formed continuously. In the fourth shape example, similarly to the first shape example described above (see FIG. 5(a)), the surface 63h is defined in such a relationship that the distance to the pickup roll 339 remains the same even when moving downward in the up-down direction V.

[0048] In the above-described first and fourth shape examples, the space S is configured to be reduced, and therefore a reduction in the amount of developer used is suppressed. In the second and third shape examples described above, the developer restricted by the layer restricting member 52 does not remain in the space S but tends to fall, so that a decrease in the amount of developer used is suppressed.

[0049] Fig. 7 is a perspective view illustrating another configuration of the limiting portion 60, where (a) shows the limiting member 62, (b) shows the limiting member 68, and (c) shows the limiting member 61. Fig. 8 is a graph illustrating the size of the block according to the position in the axial direction J, where the vertical axis shows the size of the block and the horizontal axis shows the position in the axial direction J.

[0050] 7(a) and 7(c), as well as a limiting member 68 shown in FIG. 7(b). More specifically, an end face 62b of the limiting member 62 is adjacent to an end face 68a of the limiting member 68, and an end face 68b of the limiting member 68 is adjacent to an end face 61a of the limiting member 61. That is, the limiting members 62, 68, and 61 are arranged in a row along the axial direction J. 7, a limiting member 68 is also provided in the central portion 66. In this respect, the configuration shown in Fig. 7 differs from the configuration shown in Fig. 4 in which a member constituting part of the limiting portion 60 is not provided in the central portion 66.

[0051] As shown in Fig. 8, the size of the blocks of the limiting members 61, 62, 68 varies depending on the position in the axial direction J. That is, when the limiting members 61, 62, 68 are aligned in a row, the size of the blocks is smallest at the center position in the axial direction J. The size of the blocks increases with increasing distance from the center position. The size of the blocks here refers to the size of the cross-sectional area.

[0052] 8, the cross-sectional area of ​​the limiting member 68 is smaller than those of the limiting members 62, 61. Moreover, the cross-sectional areas of the limiting members 62, 61 are smaller at end faces 62b, 61a closer to the limiting member 68 in the axial direction J than at end faces 62a, 61b farther from the limiting member 68. Furthermore, the cross-sectional area of ​​the limiting member 68 becomes smaller from the end faces 68a, 68b of the limiting member 68 toward the center. The restricting member 68 is an example of a different member.

[0053] In this way, the size of the blocks of the limiting portion 60 is large at the ends 64, 65 which are regions that are less likely to bend, while the size of the blocks of the limiting portion 60 is small at the center portion 66 which is a region that is more likely to bend. Also, the sizes of the limiting members 61, 62, 68 gradually change in the axial direction J. Therefore, the developer at the ends 64, 65 restricted by the layer restricting member 52 moves toward the center portion 66 so as to fall, thereby suppressing a decrease in the amount of developer used.

[0054] <Additional Notes> (((1))) a developer carrier for holding a developer containing a toner and a carrier and supplied to an image carrier for forming an electrostatic latent image; a regulating member that regulates the amount of the developer held on the developer holder so that the amount is a specified amount; a member provided in a region of the regulating member that is less likely to bend in an axial direction of the developer carrier than other regions of the regulating member, the member being provided so as to reduce a space below the regulating member; A developing device comprising: (((2))) the region that is less likely to bend is provided in a region excluding a middle portion in an axial direction of the developer carrier, The developing device according to (((1))) above. (((3))) The region excluding the intermediate portion is both ends in the axial direction. The developing device according to (((2))) above. (((4))) the surface of the member facing the regulating member is defined by a positional relationship with the developer carrier; The developing device according to (((1))) above. (((5))) The positional relationship is such that the distance from the developer carrier does not change even when the developer carrier moves downward. The developing device according to (((4))) above. (((6))) The positional relationship is such that the distance from the developer carrier increases downward. The developing device according to (((4))) above. (((7))) a member different from the member is provided in an area where the member is not provided, the cross-sectional area of ​​the other member is smaller than the cross-sectional area of ​​the member; The developing device according to any one of ((1))) to (((6))) above. (((8))) a member different from the member is provided in an area where the member is not provided, The cross-sectional area of ​​the member is smaller at an end closer to the other member in the axial direction than at an end farther from the other member. The developing device according to any one of ((1))) to (((6))) above. (((9))) The cross-sectional area of ​​the other member decreases from the end to the center of the other member. The developing device according to (((7))) or (((8))) above. (((10))) an image carrier for forming an electrostatic latent image; a developing means for developing the electrostatic latent image formed on the image carrier into a toner image; a transfer means for transferring the toner image produced by the developing means onto a recording material; a fixing unit for fixing the toner image transferred onto the recording material onto the recording material; Including, The developing means is a developer carrier for holding a developer containing a toner and a carrier and supplied to the image carrier for forming an electrostatic latent image; a regulating member that regulates the amount of the developer held on the developer holder so that the amount is a specified amount; a member provided in a region of the regulating member that is less likely to bend in an axial direction of the developer carrier than other regions of the regulating member, the member being provided so as to reduce a space below the regulating member; An image forming apparatus comprising:

[0055] According to the invention of (((1))), the decrease in the amount of developer used can be suppressed compared to a case where the developer continues to remain in the spaces between the components. According to the invention (((2))), the area less likely to bend can be provided in an area excluding the middle part in the axial direction of the developer holder, making it possible to increase the amount of developer that falls from the space below the regulating member, compared to a case in which the area is not provided in the area excluding the middle part in the axial direction of the developer holder. According to the invention (((3))), the area excluding the intermediate portion can suppress a decrease in the amount of developer used, compared to a case in which the area does not include both ends in the axial direction. According to the invention (((4))), the member can reduce the amount of developer remaining in the space below the regulating member, compared to a member that does not have a configuration in which the surface facing the regulating member is determined by its positional relationship with the developer carrier. According to the invention (((5))), the positional relationship is such that the distance to the developer carrier remains the same even when moving downward, and compared to a case in which the configuration is not provided, the space below the regulating member can be made narrower. According to the invention (((6))), the positional relationship is such that the distance from the developer holder increases as it goes downward, making it easier for the developer to fall from the space below the regulating member compared to a case in which no such configuration is provided. According to the invention of (((7))), a member other than the member is provided in an area where no member is provided, and the cross-sectional area of ​​the other member is smaller than the cross-sectional area of ​​the member, the reduction in the amount of developer used can be suppressed compared to a case where the configuration is not provided. According to the invention of (((8))), a component other than the component is provided in an area where no component is provided, and the cross-sectional area of ​​the component is smaller at the end closer to the other component in the axial direction than at the end farther from the other component, the reduction in the amount of developer used can be suppressed compared to a case where the component does not have a configuration in which the cross-sectional area of ​​the component is smaller at the end closer to the other component in the axial direction than at the end farther from the other component. According to the invention (((9))), the separate member can suppress a decrease in the amount of developer used, compared to a case in which the separate member does not have a configuration in which the cross-sectional area decreases from the end to the center of the separate member. According to the invention of (((10))), it is possible to suppress a decrease in the amount of developer used, compared to a case in which the developer continues to remain in the spaces between the components. [Explanation of symbols]

[0056] 1...image forming apparatus, 31...photosensitive drum, 33...developing unit, 52...layer regulating member, 60...limiting portion, 61, 62, 68...limiting member, 61a, 61b, 62a, 62b, 68a, 68b...end surface, 63a to 63i...surface, 64, 65...end portion, 66...center portion, 334...developing roll, 339...pickup roll, J...axial direction

Claims

1. a developer carrier for holding a developer containing a toner and a carrier and supplied to an image carrier for forming an electrostatic latent image; a regulating member that regulates the amount of the developer held on the developer holder so that the amount is a specified amount; a member provided in a region of the regulating member that is less likely to bend in an axial direction of the developer carrier than other regions of the regulating member, the member being provided so as to reduce a space below the regulating member; A developing device comprising:

2. the region that is less likely to bend is provided in a region excluding a middle portion in an axial direction of the developer carrier, 2. The developing device according to claim 1,

3. The region excluding the intermediate portion is both ends in the axial direction.

3. The developing device according to claim 2.

4. the surface of the member facing the regulating member is defined by a positional relationship with the developer carrier; 2. The developing device according to claim 1,

5. The positional relationship is such that the distance from the developer carrier does not change even when the developer carrier moves downward.

5. The developing device according to claim 4.

6. The positional relationship is such that the distance from the developer carrier increases downward.

5. The developing device according to claim 4.

7. a member different from the member is provided in an area where the member is not provided, the cross-sectional area of ​​the other member is smaller than the cross-sectional area of ​​the member; 2. The developing device according to claim 1,

8. a member different from the member is provided in an area where the member is not provided, The cross-sectional area of ​​the member is smaller at an end closer to the other member in the axial direction than at an end farther from the other member.

2. The developing device according to claim 1,

9. The cross-sectional area of ​​the other member decreases from the end to the center of the other member.

9. The developing device according to claim 7 or 8.

10. an image carrier for forming an electrostatic latent image; a developing means for developing the electrostatic latent image formed on the image carrier into a toner image; a transfer means for transferring the toner image produced by the developing means onto a recording material; a fixing unit for fixing the toner image transferred onto the recording material onto the recording material; Including, The developing means is a developer carrier for holding a developer containing a toner and a carrier and supplied to the image carrier for forming an electrostatic latent image; a regulating member that regulates the amount of the developer held on the developer holder so that the amount is a specified amount; a member provided in a region of the regulating member that is less likely to bend in an axial direction of the developer carrier than other regions of the regulating member, the member being provided so as to reduce a space below the regulating member; An image forming apparatus comprising:

Images