Developing apparatus, image forming apparatus

Abstract

To obtain a developing device that can reduce an amount of cloud toner to be generated compared with a case where there is only a space between a rotary member and a supply member, and an image forming apparatus.SOLUTION: A developing device comprises: a rotary member that rotates to deliver a developer to a latent image on an image holding body; a supply member that extends in an axial direction of the rotary member, is arranged obliquely below the rotary member when seen from the axial direction, and rotates to convey the developer and supply the developer to the rotary member; and an upper member that is arranged above the supply member and on the opposite side of the rotary member with respect to a tangent on the rotary member in contact with a portion on the side of the supply member when seen from the axial direction and extending in a vertical direction.SELECTED DRAWING: Figure 4

Description

Technical Field

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

Background Art

[0002] In the developing device of the supply-recovery separation type described in Patent Document 1, a shielding member extends between the surface of the developing roll and the upper surface of the tip portion of the separation plate (the inner wall surface portion that becomes the inner wall surface of the developer recovery conveyance path) at the opposing end (the tip of the separation plate) of the separation plate that partitions the developer supply conveyance path A and the developer recovery conveyance path B, and the upper surface of the shielding member is inclined downward toward the developer recovery conveyance path.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The developing device includes a rotating member that transfers the developer to the latent image of the image carrier while rotating, and a supply member that is disposed obliquely downward with respect to the rotating member and conveys the developer while rotating to supply the developer to the rotating member.

[0005] The developer remaining on the rotating member without being transferred to the image carrier returns to the supply member side and is discharged from the rotating member by the centrifugal force of the rotating member and scatters toward the supply member side. Here, the discharged developer collides with the developer being conveyed by the supply member, and cloud toner is generated.

[0006] The problem of the present disclosure is to reduce the amount of cloud toner generated as compared with the case where there is only space between the rotating member and the supply member.

Means for Solving the Problems

[0007] A developing apparatus according to a first aspect of the present disclosure is characterized by comprising: a rotating member that delivers developer to the latent image of an image holder while rotating; a supply member that extends in the axial direction of the rotating member and is positioned diagonally below the rotating member when viewed from the axial direction, and delivers developer to the rotating member while rotating; and an upper member that is positioned on the opposite side of the rotating member with respect to a vertically extending tangent that contacts the portion of the rotating member on the supply member side when viewed from the axial direction, and is positioned above the supply member.

[0008] A developing apparatus according to a second aspect of this disclosure is characterized in that, in the developing apparatus described in the first aspect, the upper member is plate-shaped, extending in the axial direction and having a plate surface facing up and down.

[0009] A developing apparatus according to a third aspect of this disclosure is characterized in that, in the developing apparatus described in the second aspect, the upper member is inclined such that one end is downward relative to the other end when viewed from the axial direction.

[0010] A developing apparatus according to a fourth aspect of this disclosure is characterized in that, in the developing apparatus described in the third aspect, the upper member is inclined such that, when viewed from the axial direction, the side opposite to the rotating member is downward.

[0011] A developing apparatus according to a fifth aspect of this disclosure is characterized in that, in the developing apparatus described in any one of the first to fourth aspects, the upper member extends to the tangent.

[0012] A developing apparatus according to a sixth aspect of the present disclosure is characterized in that, in the developing apparatus according to the fifth aspect, it comprises a plate portion which is arranged on the rotating member side with respect to the tangent and connected to the upper member, and is plate-shaped and extends in the axial direction.

[0013] A developing apparatus according to a seventh aspect of this disclosure is characterized in that, in the developing apparatus described in the sixth aspect, the plate portion is inclined such that, when viewed from the axial direction, the side opposite to the rotating member is downward.

[0014] An image forming apparatus according to the eighth aspect of this disclosure develops a latent image formed on an image holder as a toner image. Any one of the 1st to 7th forms The device is characterized by comprising a developing apparatus as described above and a transfer apparatus for transferring a toner image onto a recording medium. [Effects of the Invention]

[0015] The developing apparatus according to the first aspect of this disclosure can reduce the amount of cloud toner generated compared to the case where there is only space between the rotating member and the supply member.

[0016] The developing apparatus according to the second aspect of this disclosure can suppress collisions between the developer released from the rotating member and the developer being transported by the supply member, compared to the case in which the upper member is mesh-like.

[0017] The developing apparatus according to the third aspect of this disclosure can suppress the accumulation of developer on the upper member compared to the case in which the upper member extends horizontally when viewed from the axial direction.

[0018] The developing apparatus according to the fourth aspect of this disclosure can suppress the adhesion of the developer to the rotating member compared to the case where the rotating member is tilted downwards.

[0019] The developing apparatus according to the fifth aspect of this disclosure can suppress collisions between the developer released from the rotating member and the developer being transported by the supply member, compared to the case where the upper member is separated from the tangential.

[0020] The developing apparatus according to the sixth aspect of this disclosure can suppress the adhesion of developer released from the rotating member to the rotating member, compared to the case where there is only space between the rotating member and the supply member with respect to the tangent.

[0021] The developing device according to the seventh aspect of the present disclosure can suppress the deposition of developer on the plate portion as compared with the case where the plate portion extends in the horizontal direction when viewed from the axial direction.

[0022] The image forming apparatus according to the eighth aspect of the present disclosure can suppress the contamination of the inside of the apparatus main body of the image forming apparatus as compared with the case where the developing device having only a space between the rotating member and the supply member is provided.

Brief Description of Drawings

[0023] [Figure 1] It is a schematic configuration diagram showing an image forming apparatus according to an embodiment of the present disclosure. [Figure 2] It is a cross-sectional view showing a developing device according to an embodiment of the present disclosure. [Figure 3] It is a view in the direction of an arrow showing the flow of the developer and the like of the developing device according to an embodiment of the present disclosure. [Figure 4] It is an enlarged cross-sectional view showing a developing device according to an embodiment of the present disclosure. [Figure 5] It is a front view showing a suppressing member of the developing device according to an embodiment of the present disclosure. [Figure 6] It is a perspective view showing a supply auger or the like of the developing device according to an embodiment of the present disclosure. [Figure 7] (A)(B) It is an enlarged cross-sectional view showing a modified form of the developing device according to an embodiment of the present disclosure. [Figure 8] (A)(B) It is an enlarged cross-sectional view showing a modified form of the developing device according to an embodiment of the present disclosure. [Figure 9] It is an enlarged cross-sectional view showing a modified form of the developing device according to an embodiment of the present disclosure. [Figure 10] (A)(B) It is a drawing showing a modified form of the developing device according to an embodiment of the present disclosure. [Figure 11] It is an enlarged cross-sectional view showing a comparative form of the developing device according to an embodiment of the present disclosure.

Modes for Carrying Out the Invention

[0024] An example of an image forming apparatus according to an embodiment of the present invention will be described with reference to Figures 1 to 11. In each figure, arrow H is in the vertical direction and indicates the up-down direction of the apparatus, arrow W is in the horizontal direction and indicates the width direction of the apparatus, and arrow D is in the horizontal direction and indicates the depth direction of the apparatus.

[0025] (Overall configuration of the image forming apparatus 10) As shown in Figure 1, the image forming apparatus 10 includes an image forming unit 12 that forms a toner image by an electrophotographic method, and a transport unit 14 that transports a sheet member P as a recording medium along a transport path 16. The image forming apparatus 10 also includes a storage member 18 that houses the sheet member P, and a control unit 28 that controls the entire apparatus.

[0026] In the image forming apparatus 10 with the above configuration, the sheet member P housed in the storage member 18 is transported along the transport path 16 by the transport unit 14. Furthermore, the toner image formed by the image forming unit 12 is formed on the transported sheet member P, and the sheet member P on which the toner image has been formed is discharged to the outside of the apparatus body 10a.

[0027] [Image forming unit 12] As shown in Figure 1, the image forming unit 12 includes a plurality of toner image forming units 30, each forming a toner image of a different color, and a transfer unit 32 that transfers the toner images formed by the toner image forming units 30 to a sheet member P. Furthermore, the image forming unit 12 includes a fixing device 34 that fixes the toner images transferred to the sheet member P by the transfer unit 32 to the sheet member P.

[0028] -Toner image forming unit 30- Multiple toner image forming units 30 are provided to form toner images for each color. In this embodiment, toner image forming units 30Y, 30M, 30C, and 30K for a total of four colors—yellow (Y), magenta (M), cyan (C), and black (K)—are provided. In the following description, if it is not necessary to distinguish between yellow (Y), magenta (M), cyan (C), and black (K), the designations Y, M, C, and K will be omitted from the reference numerals.

[0029] Each toner image forming unit 30 is basically configured similarly except for the toner used, and as shown in Figure 2, it includes a rotating cylindrical image holder 40 and a charger 42 for charging the image holder 40. Furthermore, the toner image forming unit 30 includes an exposure device 44 that irradiates the charged image holder 40 with exposure light to form an electrostatic latent image, and a developing device 46 that develops the electrostatic latent image as a toner image with a developer G containing toner. (Reference form) It is equipped with the following. As a result, each toner image forming unit 30 forms an image of each color using the corresponding toner. The developing device 46 will be described in detail later.

[0030] Furthermore, each colored image holder 40 is in contact with a circulating transfer belt 50 (details will be described later), as shown in Figure 1. In the circulating direction of the transfer belt 50 (see arrows in the figure), the toner image forming units 30 for yellow (Y), magenta (M), cyan (C), and black (K) are arranged in this order from the upstream side.

[0031] -Transfer section 32- As shown in Figure 1, the transfer unit 32 includes a transfer belt 50 and primary transfer rolls 52, each positioned on the opposite side of the image holders 40 of each color from the transfer belt 50, which transfer the toner images formed on the image holders 40 of each color to the transfer belt 50.

[0032] Furthermore, the transfer section 32 includes a winding roll 56 around which the transfer belt 50 is wound, and a drive roll 58 around which the transfer belt 50 is wound and which transmits rotational force to the transfer belt 50. As a result, the transfer belt 50 rotates in the direction of the arrow in the figure.

[0033] Furthermore, the transfer section 32 is positioned on the opposite side of the winding roll 56, with the transfer belt 50 in between, and includes a secondary transfer roll 54 that transfers the toner image transferred to the transfer belt 50 to the sheet member P. A transfer nip NT is formed between the secondary transfer roll 54 and the transfer belt 50, which transfers the toner image to the sheet member P.

[0034] In this configuration, the toner image is first transferred to the transfer belt 50 by the primary transfer roll 52 in the order of yellow (Y), magenta (M), cyan (C), and black (K). The toner image is then transferred from the transfer belt 50 to the sheet member P, which is transported sandwiched between the transfer belt 50 and the secondary transfer roll 54, by the secondary transfer roll 54. The sheet member P, on which the toner image has been transferred, is then transported toward the fuser unit 34.

[0035] - Fixing device 34 - As shown in Figure 1, the fixing device 34 is positioned downstream of the transfer nip NT in the transport direction of the sheet member P. The fixing device 34 heats and pressurizes the toner image transferred to the sheet member P to fix it to the sheet member P.

[0036] [Conveying section 14] As shown in Figure 1, the transport unit 14 includes a delivery roll 20 that sends the sheet member P housed in the storage member 18 to the transport path 16, and a prevention roll 22 that prevents double feeding of the sheet member P sent out by the delivery roll 20. Furthermore, the transport unit 14 includes an adjustment roll 24 that adjusts the timing of the sheet member P being sent to the transfer nip NT, and an discharge roll 26 that discharges the sheet member P, on which the toner image has been fixed by the fixing device 34, to the outside of the device body 10a.

[0037] (Main part configuration) Next, the developing device 46 will be described.

[0038] As shown in Figure 2, the developing apparatus 46 comprises a housing 72, a developing roll 60 positioned opposite the image holder 40, a supply auger 66 for supplying developer G to the developing roll 60, and a stirring auger 68 for stirring the developer G. The developing roll 60 is an example of a rotating member, and the supply auger 66 is an example of a supply member.

[0039] Furthermore, the developing apparatus 46 is equipped with a suppression member 80 positioned above the supply auger 66. The developer G is a two-component developer G mainly composed of toner T and magnetic carrier particles (hereinafter referred to as "carrier C").

[0040] [Cabinet 72] As shown in Figure 2, the housing 72 is positioned next to the image holder 40, and in the portion of the housing 72 facing the image holder 40, an opening 72a is formed that extends in the depth direction of the device, opening the inside of the housing 72.

[0041] Furthermore, in the housing 72, a transfer path 72b, where the developing roll 60 is located, is formed extending in the depth direction of the device, on the opposite side of the image holder 40 across the opening 72a. In addition, in the housing 72, a supply path 72c, where the supply auger 66 is located, is formed diagonally below the transfer path 72b, extending in the depth direction of the device. In addition, in the housing 72, an agitation path 72d, where the agitation auger 68 is located, is formed extending in the depth direction of the device, on the opposite side of the transfer path 72b across the supply path 72c. Furthermore, in the housing 72, a partition wall 72e is formed between the supply path 72c and the agitation path 72d, separating the supply path 72c and the agitation path 72d.

[0042] The supply passage 72c and the stirring passage 72d have a U-shaped cross-section, as shown in Figure 2. Furthermore, the partition wall 72e extends diagonally upward when viewed from the depth direction of the apparatus, and as shown in Figure 3, it separates the supply passage 72c and the stirring passage 72d, except for the rear portion of the supply passage 72c and the front portion of the supply passage 72c in the depth direction of the apparatus. Figure 3 is a view of the inside of the housing 72 of the developing apparatus 46, as seen from the direction in which the partition wall 72e of the developing apparatus 46 shown in Figure 2 extends (arrow J01 in the figure).

[0043] Furthermore, as shown in Figure 2, a stepped surface 72f facing the developing roll 60 is formed on the inner wall surface of the housing 72 above the supply passage 72c. In addition, a layer thickness regulating plate 74 for regulating the layer thickness of the developer G is positioned in the lower part of the transfer passage 72b.

[0044] [Developing Roll 60] The developing roll 60 is positioned in the transfer path 72b, as shown in Figure 2, with its axial direction being the depth direction of the apparatus. A gap (developing gap) is formed between the developing roll 60 and the image holder 40 to transfer the developer G from the developing roll 60 to the image holder 40.

[0045] The developing roll 60 comprises a magnetic roll 60a with a circular cross-section and a rotating sleeve 60b that is placed over the magnetic roll 60a and rotates around the magnetic roll 60a. The rotating sleeve 60b is rotated clockwise by a rotational force transmitted from a drive source (not shown).

[0046] Furthermore, the magnetic roll 60a has a total of five magnetic poles: N1 and N2 with north polarity and S1, S2 and S3 with south polarity, and is arranged in the circumferential direction in the order of S1, N1, S2, S3, N2 at predetermined intervals.

[0047] Specifically, a developing electrode S1 is positioned opposite the image holder 40, and a regulating electrode N2 is positioned upstream of the developing electrode S1 in the rotational direction of the developing roll 60 to regulate the thickness of the developer G layer.

[0048] Furthermore, a peeling electrode S2 and a pumping electrode S3 are positioned downstream of the developing electrode S1 and upstream of the regulating electrode N2, and a transport electrode N1 is positioned between the developing electrode S1 and the peeling electrode S2.

[0049] In this configuration, the developer G adsorbed on the surface of the rotating sleeve 60b near the pumping electrode S3 is transported from the regulating electrode N2 to the developing electrode S1 and then to the transport electrode N1. As it passes through the regulating electrode N2, the layer thickness of the developer G is standardized by the layer thickness regulating plate 74, and near the developing electrode S1, the non-magnetic toner T on the magnetic brush is transferred to the image holder 40, leaving the magnetic brush, which consists almost entirely of magnetic carriers, on the surface of the rotating sleeve 60b. As the rotating sleeve 60b rotates, the magnetic brush, now consisting only of magnetic carriers, is released from the surface of the rotating sleeve 60b by the peeling electrode S2 and scattered toward the supply auger 66.

[0050] [Supply Auger 66] The supply auger 66 is positioned in the supply path 72c, with its axial direction being the depth direction of the device, as shown in Figure 2. The supply auger 66 is composed of a supply shaft 66a extending in the depth direction of the device, and two spiral supply blades 66b and 66c formed on the outer circumferential surface of the supply shaft 66a, as shown in Figure 3.

[0051] Both ends of the supply shaft 66a are rotatably supported by the walls of the housing 72, and a gear (not shown) to which rotational force is transmitted from the drive source is fixed to one end of the supply shaft 66a.

[0052] In this configuration, the rotating supply auger 66 agitates the developer G in the supply passage 72c and transports it from the front side (left side in the diagram) to the back side (right side in the diagram) in the depth direction of the device, supplying the developer G to the developing roll 60. The rotating supply auger 66 also transfers the developer G to the agitating auger 68 through the connecting passage 72k at the back side in the depth direction of the device.

[0053] [Agitation Auger] The stirring auger 68 is positioned in the stirring channel 72d, with its axial direction being the depth direction of the apparatus, as shown in Figure 2. The stirring auger 68 is composed of a stirring shaft 68a extending in the depth direction of the apparatus, and two spiral stirring blades 68b and 68c formed on the outer circumferential surface of the stirring shaft 68a, as shown in Figure 3.

[0054] Both ends of the stirring shaft 68a are rotatably supported by the walls of the housing 72, and a gear (not shown) is fixed to one end of the stirring shaft 68a, to which rotational force is transmitted from the drive source.

[0055] In this configuration, the rotating supply auger 66 and the rotating agitation auger 68 transport the developer G, and the developer G circulates between the supply passage 72c and the agitation passage 72d (see arrow in Figure 3).

[0056] [Suppression member 80] The restraining member 80 extends in the depth direction of the device and, as shown in Figure 4, is located inside the housing 72 and above (directly above) the supply auger 66. The restraining member 80 comprises a restraining plate 82 whose thickness direction is vertical and a support portion 92 that supports the restraining plate 82.

[0057] -Suppression plate 82- As shown in Figure 4, the suppression plate 82 is positioned to straddle the tangent L01 that extends vertically and contacts the portion of the developing roll 60 on the supply auger 66 side when viewed from the depth direction of the apparatus. Here, the portion of the suppression plate 82 that moves away from the developing roll 60 with respect to the tangent L01 is called one portion 82a, and the portion of the suppression plate 82 that moves closer to the developing roll 60 with respect to the tangent L01 is called the other portion 82b. Thus, the suppression plate 82 is formed from one portion 82a and the other portion 82b. One portion 82a is an example of an upper member, and the other portion 82b is an example of a plate portion.

[0058] The suppression plate 82 is inclined such that, when viewed from the depth direction of the apparatus, the side opposite to the developing roll 60 is downward. In other words, the upper surface 82c of the suppression plate 82, which faces upward, is inclined such that, when viewed from the depth direction of the apparatus, the side opposite to the developing roll 60 is downward.

[0059] Furthermore, a space is formed between one end of the suppression plate 82 in the device width direction (right end in the figure) and the inner wall surface of the housing 72. In addition, a gap is formed between the other end of the suppression plate 82 in the device width direction (left end in the figure) and the developing roll 60. The portion of the developing roll 60 facing the other end of the suppression plate 82 is positioned downstream of the peeling electrode S2.

[0060] -Support part 92- As shown in Figure 4, the support portion 92 is inclined such that its upper end moves away from the developing roll 60 relative to its lower end when viewed from the depth direction of the apparatus. When viewed from a direction perpendicular to the direction in which the support portion 92 is inclined (direction of arrow J02 in Figure 4), the support portion 92 has a main body portion 94 that extends in the depth direction of the apparatus and a plurality of extension portions 96 that extend from the main body portion 94 to the suppression plate 82, as shown in Figure 5. Multiple extension portions 96 are provided at predetermined intervals in the depth direction of the apparatus, and the lower ends of the extension portions 96 are connected to the upper surface 82c of the suppression plate 82.

[0061] Furthermore, as shown in Figure 6, the extension portion 96 is plate-shaped with the thickness direction in the depth direction of the device, and the end face of the extension portion 96 facing the developing roll 60 (see Figure 4) is an arcuate surface 96a. The main body portion 94 is attached to the stepped surface 72f (see Figure 4) of the housing 72.

[0062] (Function of the main components) Next, the operation of the developing device 46 will be described. The operation of the developing device 46 will be described in comparison with the developing device 946, which is a comparative configuration. Unlike the developing device 46, the developing device 946 does not have a suppression member, as shown in Figure 11. The other components of the developing device 946 are the same as those of the developing device 46.

[0063] Inside the housing 72 of the developing units 46 and 946, the rotating supply auger 66 and the rotating agitating auger 68 circulate the developer G between the supply passage 72c and the agitating passage 72d while agitating it, as shown in Figure 3 (see arrows in the figure). As the developer G is agitated, the toner T and carrier C in the developer G rub against each other, causing the toner T to become triboelectrically charged to a predetermined polarity. In addition, when the developing units 46 and 946 are in operation, the air pressure inside the housing 72 becomes higher than the air pressure outside.

[0064] A rotating supply auger 66 supplies developer G to the developing roll 60, as shown in Figures 4 and 11. The developer G supplied to the developing roll 60 is held in place by the magnetic force of the magnet roll 60a, forming magnetic brushes (not shown) on the surface of the developing roll 60. The rotating sleeve 60b then transports the developer G.

[0065] The rotating sleeve 60b transports the developer G to a position opposite the image holder 40. The toner T contained in the developer G transported to the position opposite the image holder 40 adheres to the electrostatic latent image formed on the image holder 40, and the electrostatic latent image is made visible as a toner image. The developer G, which has passed the position opposite the image holder 40 and whose proportion of toner T has decreased, is transported by the rotating sleeve 60b to the part opposite the peeling electrode S2, where it is released from the developing roll 60 by the centrifugal force of the rotating sleeve 60b and scattered toward the supply auger 66.

[0066] In this comparative configuration, the developing apparatus 946 does not have a suppression member. In other words, there is only space between the developing roll 60 and the supply auger 66. Therefore, in the developing apparatus 946, as shown in Figure 11, most of the developer G released from the developing roll 60 collides with the developer G being transported by the supply auger 66, generating cloud toner. This cloud toner is then carried by the airflow and discharged to the outside through the opening 72a of the housing 72. Cloud toner refers to toner that floats in the air.

[0067] Furthermore, some of the developer G released from the developing roll 60 is resupplied to the developing roll 60 by the magnetic force of the pump pole S3. The proportion of toner T in the resupplied developer G is reduced. As a result, the electrostatic latent image of the image holder 40 is visualized by this developer G with a reduced proportion of toner T, causing a decrease in density in the visualized toner image.

[0068] On the other hand, the developing apparatus 46 according to this embodiment is equipped with a suppression member 80. Therefore, in the developing apparatus 46, as shown in Figure 4, most of the developer G released from the developing roll 60 collides with one portion 82a of the suppression plate 82. Then, most of the developer G slides along the upper surface 82c of the suppression plate 82, passes between the extensions 96 (see Figure 6) which are spaced apart in the depth direction of the apparatus, and falls back into the supply path 72c from one end of the suppression plate 82.

[0069] Furthermore, some of the developer G released from the developing roll 60 collides with the other portion 82b of the suppression plate 82. As a result, some of the developer G is prevented from being supplied back to the developing roll 60 by the magnetic force of the pump pole S3, and some of the developer G slides along the upper surface 82c of the suppression plate 82, passes between the extensions 96 (see Figure 6) which are spaced apart in the depth direction of the apparatus, and falls back into the supply path 72c from one end of the suppression plate 82.

[0070] (summary) As explained above, in the developing apparatus 46, the suppression plate 82 is positioned above the supply auger 66. Therefore, most of the developer G released from the developing roll 60 collides with one portion 82a of the suppression plate 82. This suppresses collision between the developer G released from the developing roll 60 and the developer G being transported by the supply auger 66. As a result, the amount of cloud toner generated is reduced compared to the developing apparatus 946 of the comparative configuration.

[0071] Furthermore, in the developing apparatus 46, the suppression plate 82 is a plate that extends in the depth direction of the apparatus and has its surface facing up and down. In other words, one portion 82a of the suppression plate 82 is also a plate that extends in the depth direction of the apparatus and has its surface facing up and down. This suppresses collisions between the developer G released from the developing roll 60 and the developer G being transported by the supply auger 66, compared to the case where one portion of the suppression plate is mesh-like.

[0072] Furthermore, in the developing apparatus 46, the suppression plate 82 is inclined with respect to the horizontal when viewed from the depth direction of the apparatus. In other words, one portion 82a of the suppression plate 82 is also inclined with respect to the horizontal when viewed from the depth direction of the apparatus. As a result, compared to the case where one portion of the suppression plate extends horizontally when viewed from the depth direction of the apparatus, the accumulation of developer G on one portion 82a of the suppression plate 82 is suppressed.

[0073] Furthermore, in the developing apparatus 46, the suppression plate 82 is inclined such that, when viewed from the depth direction of the apparatus, the side opposite to the developing roll 60 is downward. In other words, one portion 82a of the suppression plate 82 is also inclined such that, when viewed from the depth direction of the apparatus, the side opposite to the developing roll 60 is downward. This suppresses the developer G that collides with one portion 82a of the suppression plate 82 from sliding towards the developing roll 60 and adhering to the developing roll 60, compared to the case where the developing roll 60 side is inclined downward.

[0074] Furthermore, in the developing apparatus 46, one portion 82a of the suppression plate 82 is the portion of the suppression plate 82 that is away from the developing roll 60 with respect to the tangent L01 when viewed from the depth direction of the apparatus. In other words, one portion 82a extends to the tangent L01. As a result, compared to the case where one portion 82a of the suppression plate 82 is away from the tangent L01 when viewed from the depth direction of the apparatus, collision between the developer G released from the developing roll 60 and the developer G being transported by the supply auger 66 is suppressed.

[0075] Furthermore, in the developing apparatus 46, the other portion 82b of the suppression plate 82 is the portion of the suppression plate 82 that approaches the developing roll 60 with respect to the tangent L01. In other words, when viewed from the depth direction of the apparatus, the other portion 82b is connected to the one portion 82a. As a result, compared to the case where there is only space between the developing roll and the supply auger, and the developing roll side with respect to the tangent L01 is the amount of developer G released from the developing roll 60 that adheres to the developing roll 60.

[0076] Furthermore, in the developing device 46, the adhesion of the developer G released from the developing roll 60 to the developing roll 60 is suppressed, thereby suppressing the occurrence of white streaks in the visualized toner image compared to the case where there is only space between the one-sided portion 82a and the developing roll 60.

[0077] Furthermore, in the developing apparatus 46, the suppression plate 82 is inclined such that, when viewed from the depth direction of the apparatus, the side opposite to the developing roll 60 is downward. In other words, the other portion 82b of the suppression plate 82 is also inclined such that, when viewed from the depth direction of the apparatus, the side opposite to the developing roll 60 is downward. As a result, compared to the case where the other portion of the suppression plate extends horizontally when viewed from the depth direction of the apparatus, the accumulation of developer G on the other portion 82b of the suppression plate 82 is suppressed.

[0078] Furthermore, in the image forming apparatus 10, compared to the case where a developing device 946 is provided according to the comparative configuration, the discharge of cloud toner from the developing device 46 into the main body 10a of the image forming apparatus 10 is suppressed, thereby suppressing contamination inside the main body 10a of the image forming apparatus 10.

[0079] (Transformed form) Next, several variations of this embodiment will be described.

[0080] [First transformation form] The developing apparatus 146 according to the first modified form will be described mainly for its differences from the developing apparatus 46. The suppression member 180 of the developing apparatus 146 is equipped with a suppression plate 182, as shown in Figure 7(A). This suppression plate 182 is attached to the inner wall of the housing 72 at both ends in the depth direction of the apparatus.

[0081] Furthermore, the suppression plate 182 is formed from one portion 82a and the other portion 182b. The other portion 182b has an L-shaped cross-section. Specifically, the other portion 182b has a partition plate 184 that divides the space between the developing roll 60 and the supply auger 66 in the width direction of the apparatus. This partition plate 184 extends in the vertical direction and is inclined with respect to the vertical direction such that its lower end is located on the developing roll 60 side relative to its upper end.

[0082] This partition plate 184 prevents the developer G released from the developing roll 60 from adhering to the developing roll 60. By preventing the developer G from adhering to the developing roll 60, a decrease in density in the toner image visualized by the developing device 146 is suppressed.

[0083] [Second transformation form] The developing apparatus 246 according to the second modified form will be described mainly in terms of the parts that differ from the developing apparatus 46. The suppression member 280 of the developing apparatus 246 is equipped with a suppression plate 282, as shown in Figure 7(B). This suppression plate 282 is attached to the inner wall of the housing 72 at both ends in the depth direction of the apparatus.

[0084] Furthermore, the restraint plate 282 is formed from one portion 82a and the other portion 282b. The inclination angle of the other portion 282b with respect to the horizontal direction is larger than that of the one portion 82a. In other words, the inclination angle of the one portion 82a is smaller than that of the other portion 282b.

[0085] Here, the developer G that collides with the other section 282b slides along the one section 82a, which has a reduced inclination angle, and then falls back into the supply path 72c from one end of the suppression plate 282. In this way, because the developer G slides along the one section 82a, which has a reduced inclination angle, and then falls into the supply path 72c from one end of the suppression plate 282, the falling speed of the developer G into the supply path 72c is slower compared to when the inclination angle of the other section 282b is maintained. This slower falling speed reduces the amount of cloud toner generated by collisions with the developer G being transported by the supply auger 66.

[0086] Furthermore, the end of the other portion 282b on the developing roll 60 side is positioned higher than the end of the other portion 82b on the developing roll 60 side according to this embodiment. This suppresses the adhesion of developer G to the developing roll 60 when it collides with the other portion 282b. By suppressing adhesion to the developing roll 60, a decrease in density in the toner image visualized by the developing device 246 is suppressed.

[0087] [Third transformation form] Regarding the developing apparatus 346 according to the third modified form, we will mainly describe the parts that differ from the developing apparatus 246 according to the second modified form. The suppression member 380 of the developing apparatus 346 is equipped with a suppression plate 382, ​​as shown in Figure 8(A).

[0088] Furthermore, one end of the suppression plate 382 is lower than the other end. The inclination angle changes in three stages, with the angle decreasing progressively from the part closest to the developing roll 60. This gradually slows down the sliding speed of the developer G sliding on the suppression plate 382. Other effects are the same as in the second modified form.

[0089] [Fourth transformation form] Regarding the developing apparatus 446 according to the fourth modified form, the differences from the developing apparatus 346 described in the third modified form will be mainly explained. The suppression member 480 of the developing apparatus 446 is equipped with a suppression plate 482, as shown in Figure 8(B).

[0090] Furthermore, one end of the suppression plate 482 is lower than the other end, and the angle of inclination gradually changes. Specifically, the suppression plate 482 is curved when viewed from the depth direction of the apparatus. This gradually slows down the sliding speed of the developer G sliding on the suppression plate 482. Other effects are the same as in the third modified form.

[0091] [Fifth Transformation Form] Developing apparatus 546 relating to the fifth modified form (Reference form) The following will mainly explain the differences between the developing apparatus 546 and the developing apparatus 46. As shown in Figure 9, the developing apparatus 546 is equipped with a suppression plate 82 and a collision plate 584. The suppression plate 82 is attached to the inner wall of the housing 72 at both ends in the depth direction of the apparatus.

[0092] The impact plate 584 extends in the depth direction of the device and has a rectangular cross-section. The impact plate 584 is cantilevered to the stepped surface 72f of the housing 72.

[0093] In this configuration, a portion of the developer G released from the developing roll 60 collides with the collision plate 584. The developer G, whose speed has been slowed by the collision, falls into the supply path 72c via the suppression plate 82. As a result, the amount of cloud toner generated by collisions with the developer G being transported by the supply auger 66 is reduced compared to the case where the speed of the developer G is maintained.

[0094] [Sixth Transformation Form] Regarding the developing apparatus 646 according to the sixth modified form, the differences from the developing apparatus 46 will be mainly described. As shown in Figure 10(A), the support portion 692 of the developing apparatus 646 comprises a main body portion 94 and a plurality of extension portions 696.

[0095] The extension portion 696 is inclined such that its upper end is on the far side in the depth direction of the device relative to its lower end. This inclination suppresses the accumulation of developer G on the end face of the extension portion 696 that faces the developing roll 60 (see Figure 4), compared to the case where the upper and lower ends are in the same position in the depth direction of the device.

[0096] [Seventh Transformation Form] Regarding the developing apparatus 746 according to the seventh modified form, the differences from the developing apparatus 46 will be mainly described. As shown in Figure 10(B), the support portion 792 of the developing apparatus 746 comprises a main body portion 94 and a plurality of extension portions 796.

[0097] The extension portion 796 has a staggered arrangement of its upper and lower ends in the depth direction of the device. In other words, the extension portion 796 is arranged in a zigzag pattern. This zigzag arrangement suppresses the accumulation of developer G on the end face of the extension portion 796 that faces the developing roll 60 (see Figure 4), compared to the case where the upper and lower ends are in the same position in the depth direction of the device.

[0098] Although this disclosure has described specific embodiments in detail, it will be apparent to those skilled in the art that this disclosure is not limited to these embodiments, and that various other embodiments are possible within the scope of this disclosure. For example, in the above embodiment, the suppression plate 82 is in the shape of a plate, but it may be a mesh or the like. In this case, the effect achieved by being in the shape of a plate will not be achieved.

[0099] Furthermore, although the suppression plate 82 was inclined in the above embodiment, it may also be horizontal. In this case, the effect achieved by the inclination of the suppression plate will not be achieved.

[0100] Furthermore, in the above embodiment, one portion 82a extended to the tangent line L01, but one portion may be spaced apart from the tangent line L01. In this case, the effect achieved by one portion 82a extending to the tangent line L01 will not be achieved.

[0101] Furthermore, in the above embodiment, the suppression plate 82 had the other portion 82b, but the suppression plate may be composed of only one portion. In this case, the effect achieved by having the other portion will not be achieved.

[0102] Furthermore, although not specifically mentioned in the above embodiment, in this embodiment, the change in the amount of cloud toner is derived by measuring the amount of cloud toner discharged from the opening 72a of the housing 72.

[0103] Furthermore, although not specifically mentioned in the above embodiment, it is preferable to position the suppression plate 82 so that it does not come into contact with the supply auger 66. This slows down the speed of the developer G when it falls from the suppression plate 82 and collides with the developer G in the supply path 72c, thereby reducing the amount of cloud toner generated by the collision.

[0104] Furthermore, although not specifically described in the above embodiment, the inclination angle of the suppression plate 82 is preferably about 20 degrees with respect to the horizontal direction, from the viewpoint of allowing the developer G that collides with the suppression plate 82 to slide and from the viewpoint of slowing down the speed of the developer G falling from the suppression plate 82.

[0105] Furthermore, in the above embodiment, the end face of the extension portion 96 facing the developing roll 60 side is an arcuate surface 96a, but it may also be a V-shaped surface with its apex facing the developing roll 60 side. [Explanation of Symbols]

[0106] 10 Image forming apparatus 10a Main unit of the device 32 Transfer section (an example of a transfer device) 40 Image holder 46 Developing device 60. Developing roll (an example of a rotating component) 66. Supply Auger (Example of a supply component) 82 Suppression plate 82a One portion (an example of an upper member) 82b Other part (an example of a plate section) 146 Developing device 182 Suppression plate 182b Other part (an example of a plate section) 246 Developing equipment 282 Suppression plate 282b Other part (an example of a plate section) 346 Phenomenon Device 382 Suppression Plate 446 Phenomenon Device 482 Suppression Plate 546 Phenomenon Device 646 Phenomenon Device 746 Phenomenon Device

Claims

1. A rotating member that rotates while transferring developer to the latent image of the image holder, A supply member extending in the axial direction of the rotating member and positioned diagonally below the rotating member when viewed from the axial direction, and which rotates to transport the developer and supply the developer to the rotating member, An upper member is positioned above the supply member, on the opposite side of the rotating member from the tangent line extending vertically that contacts the portion of the rotating member on the supply member side when viewed from the axial direction, It comprises a plate portion which is positioned on the rotating member side with respect to the tangent and connected to the upper member, and is plate-shaped and extends in the axial direction, The inclination angle of the upper member when viewed from the axial direction is different from the inclination angle of the plate portion when viewed from the axial direction, and the inclination angle of the upper member when viewed from the axial direction is smaller than that of the plate portion. Developing device.

2. The upper member is plate-shaped, extending in the axial direction and having its surface facing vertically. The developing apparatus according to claim 1.

3. The upper member is inclined such that, when viewed from the axial direction, one end is lower than the other end. The developing apparatus according to claim 2.

4. The upper member is inclined such that, when viewed from the axial direction, the side opposite to the rotating member is downward. The developing apparatus according to claim 3.

5. The upper member extends to the tangent, A developing apparatus according to any one of claims 1 to 4.

6. The plate portion is inclined such that, when viewed from the axial direction, the side opposite to the rotating member is downward. The developing apparatus according to claim 1.

7. When viewed from the axial direction, the upper member and the plate portion are curved. The developing apparatus according to claim 1.

8. A developing apparatus according to any one of claims 1 to 7, which develops a latent image formed on an image holder as a toner image, A transfer device that transfers a toner image onto a recording medium, An image forming apparatus equipped with the following features.

Images