Developing device and image forming apparatus

Abstract

A developing device and an image forming apparatus, the developing device including: a developer holding body that holds a developer; an accommodating portion accommodating the developer supplied to the developer holding body; the rotating shaft is rotatably arranged in the accommodating part; a first conveying section that is provided on the rotating shaft and conveys the developer in a direction intersecting an axial direction of the rotating shaft; a second conveying section that is provided on the rotating shaft and conveys the developer in the axial direction; a discharge port that is provided in the accommodating portion and discharges a portion of the developer to the outside at a position corresponding to a position at which the first conveying portion is provided in the axial direction; and a pressure adjustment port which is provided in the accommodating part and adjusts the pressure of the accommodating part at a position corresponding to the position where the first conveying part is provided in the axial direction in the rotation direction of the first conveying part of the discharge port.

Description

Technical Field

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

[0002] Patent document 1 discloses a developing machine, which comprises: a discharge portion, which is arranged on the downstream side of a stirring chamber in the first direction and is arranged on the downstream side of the first direction more than a return blade, and discharges a part of the developer from the developing device; a first path, which connects a portion of the stirring chamber above the return blade with the discharge portion to discharge the developer to the discharge portion; and a second path, which is separated from the first path by a partition wall, and connects a portion of the stirring chamber above the agent surface of the developer contained in the stirring chamber with the discharge portion to allow air to flow from the stirring chamber to the discharge portion.

[0003] Patent document 2 discloses the following: the developer in the developing chamber is transported in one direction as the first transport screw rotates. If the colorant and the carrier are replenished into the developing chamber from the hopper, a part of the circulating developer will overflow and be discharged from the developer discharge port. The first transport screw is formed with spiral blades in a portion other than the area along the developer discharge port of the developing chamber, and ribs are locally formed in this area for stirring or vibrating the developer in the area along the developer discharge port as the first transport screw rotates.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2021-96400

[0005] Patent Document 2: Japanese Patent Application Publication No. 2012-234153 Summary of the invention

[0006] In an image forming apparatus using an electrophotographic method or the like, an electrostatic latent image formed on an image holding member is developed into a toner image by a developing device. In such a developing device, a so-called trickle mechanism is used to gradually replace the developer by discharging the remaining developer from a discharge port and replenishing the developer with new developer in order to suppress the deterioration of the developer. When the developer is discharged from the discharge port using the trickle mechanism, if the pressure at the discharge port changes, the amount of the discharged developer changes.

[0007] An object of the present invention is to suppress variation in the amount of developer discharged.

[0008] The invention described in Scheme 1 is a developing device, which comprises: a developer retaining body for retaining the developer; a containing portion for containing the developer supplied to the developer retaining body; a rotating shaft rotatably arranged inside the containing portion; a first conveying portion arranged on the rotating shaft and conveying the developer along a direction intersecting the axial direction of the rotating shaft; a second conveying portion arranged on the rotating shaft and conveying the developer along the axial direction; a discharge port arranged in the containing portion and discharging a portion of the developer to the outside at a position corresponding to a position where the first conveying portion is arranged in the axial direction; and a pressure adjusting port arranged in the containing portion and adjusting the pressure of the containing portion at a position of the discharge port in the rotational direction of the first conveying portion corresponding to a position where the first conveying portion is arranged in the axial direction.

[0009] The invention described in Scheme 2 is characterized in that in the developing device described in Scheme 1, the first conveying portion includes a conveying surface portion, the conveying surface portion is a surface that conveys the developer in the intersecting direction while the rotating shaft rotates, the discharge port is arranged at a position overlapping with at least a portion of the conveying surface portion in the axial direction, and the pressure adjustment port is arranged at a position overlapping with at least a portion of the conveying surface portion in the axial direction.

[0010] The invention described in claim 3 is characterized in that in the developing device described in claim 1, at least a portion of the discharge port and the pressure regulating port in the axial direction overlap in the rotational direction of the first conveying portion.

[0011] The invention described in Scheme 4 is characterized in that in the developing device described in any one of Schemes 1 to 3, the second conveying section comprises: a stirring conveying section, which stirs the developer while conveying the developer in one direction; and a reversing section, which is arranged at the end portion in the axial direction of the rotating shaft and conveys the developer conveyed in one direction by the stirring conveying section to a direction opposite to the one direction, and the first conveying section is arranged in the axial direction at a position where the reversing section is configured.

[0012] The invention described in claim 5 is characterized in that in the developing device described in any one of claims 1 to 3, the second conveying portion is a blade spirally provided on the rotating shaft, and the first conveying portion is provided between the spiral blades.

[0013] The invention described in claim 6 is characterized in that in the developing device described in claim 5, the first conveying portion is arranged between the blades and is arranged to be biased toward the surface side of the blade that conveys the developer.

[0014] The invention described in claim 7 is characterized in that, in the developing device described in claim 6, a gap is provided between the blade and the first conveying portion.

[0015] The invention described in claim 8 is characterized in that in the developing device according to any one of claims 5 to 7, a tip end of the first conveying portion is located closer to the center side of the rotating shaft than a tip end of the blade.

[0016] The invention described in claim 9 is characterized in that in the developing device described in claim 1, the opening of the discharge port and the opening of the pressure adjustment port are formed by a common opening which is an opening provided in the accommodating portion and a sealing portion which seals a part of the common opening.

[0017] The invention described in claim 10 is characterized in that in the developing device described in claim 9, the blocking portion changes the position and / or shape of the discharge port and the pressure regulating port according to the characteristics of the developer accommodated in the accommodating portion.

[0018] The invention described in claim 11 is characterized in that in the developing device described in claim 9, the blocking portion has a slope that moves the developer entering the opening of the pressure regulating port toward the accommodating portion.

[0019] The invention described in claim 12 is an image forming apparatus comprising the developing device described in any one of claims 1 to 11, and forms an image on a recording material by developing an electrostatic latent image formed on a photoreceptor using a developer whose charge has been stabilized by the developing device.

[0020] Effects of the Invention

[0021] According to the first aspect of the present invention, variation in the amount of developer to be discharged is suppressed.

[0022] According to the second aspect of the present invention, compared with a case where no conveying surface portion is provided, the developer amount can be stably discharged, thereby suppressing the fluctuation in the developer amount.

[0023] According to the third aspect of the present invention, the flow of air is improved and the pressure regulation is improved compared to the case where the discharge port and the pressure regulating port do not partially overlap.

[0024] According to the fourth aspect of the present invention, when the amount of developer in the containing portion increases, the developer is discharged quickly.

[0025] According to the fifth aspect of the present invention, the developer can be discharged by utilizing a mechanism for conveying the developer using a blade.

[0026] According to the sixth aspect of the present invention, the developer discharge amount is increased compared to the case where the first conveying portion is provided away from the surface of the blade that conveys the developer.

[0027] According to the seventh aspect of the present invention, the variation in the amount of developer discharged is suppressed compared to a case where there is no gap between the blade and the first conveying portion.

[0028] According to the eighth aspect of the present invention, compared with a case where the distal end of the first conveying portion protrudes further than the distal end of the blade, it is possible to suppress the developer from being discharged from the pressure regulating port.

[0029] According to the ninth aspect of the present invention, the shape of the discharge port and the shape of the pressure regulating port can be easily changed.

[0030] According to the tenth aspect of the present invention, the variation in the amount of developer to be discharged is suppressed according to the type of developer.

[0031] According to the eleventh aspect of the present invention, the outflow of air from the pressure regulating port is allowed, while the discharge of the developer is suppressed.

[0032] According to the twelfth aspect of the present invention, the quality of an image formed on a recording material is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Embodiments of the present invention will be described in detail with reference to the following drawings.

[0034] Figure 1 is a diagram illustrating an image forming apparatus;

[0035] Figure 2 is a diagram illustrating a developer;

[0036] Figure 3 is a diagram for explaining the interior of the container. Figure 2 The upper side in the up-down direction shows the internal structure of the accommodation portion;

[0037] Figure 4 is a perspective view showing an end portion side immediately in front of a housing portion extending in the axial direction;

[0038] Figure 5 It means in Figure 4 A perspective view of a state in which the blocking portion is removed;

[0039] Figure 6 It is a detailed representation Figure 4 A diagram of the occluded portion shown;

[0040] Figure 7 is from Figure 4 VII direction of the internal view of the stirring channel, is a diagram illustrating the positional relationship between the discharge paddle, the discharge port and the pressure regulating port in the axial direction;

[0041] Figure 8 Yes means Figure 3 The figure showing a part of the VIII-VIII cross section of FIG. 1 is a figure for explaining the positional relationship among the discharge paddle, the discharge port, and the pressure regulating port in a direction intersecting the axial direction.

[0042] Explanation of symbols

[0043] 1-image forming device, 33-developer, 53-accommodating portion, 54-replenishing passage, 55-stirring passage, 56-supply passage, 57-colorant bottle, 58-discharge path, 61-developer replenishing port, 63-connecting portion, 64-through hole, 65-sealing portion, 68-discharge port, 69-pressure regulating port, 550-stirring screw augers, 551-rotating shaft, 552-spiral blades, 554-discharge paddles, 554a-discharge surface, 641-inner side opening, 642-outer side opening, 643-lower inner surface, 644-upper inner surface, 651-upper surface, 652-lower surface, 658-recessed portion. DETAILED DESCRIPTION

[0044] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0045] [Description of image forming apparatus]

[0046] Figure 1 It is a diagram for explaining the image forming apparatus 1 .

[0047] The image forming apparatus 1 according to the present embodiment includes a paper feeding unit 1A, a printing unit 1B, and a paper discharge unit 1C.

[0048] The paper feeding unit 1A includes first to fourth paper accommodating sections 11 to 14 for accommodating paper P as an example of recording media.

[0049] The paper feeding unit 1A is provided corresponding to the first to fourth paper accommodating portions 11 to 14 , respectively, and is provided with delivery rollers 15 to 18 for delivering the paper P accommodated in each paper accommodating portion to a transport path connected to the printing unit 1B.

[0050] The printing unit 1B includes an image forming section 20 that forms an image on the paper P. The printing unit 1B is also provided with a control section 21 that controls each section of the image forming apparatus 1 .

[0051] Furthermore, the printing unit 1B includes an image processing unit 22 . The image processing unit 22 performs image processing on image data sent from the image reading device 4 or the personal computer (PC) 5 .

[0052] Furthermore, the printing unit 1B is provided with a UI (User Interface) 23 which is constituted by a touch panel or the like and which notifies information to the user and accepts input of information from the user.

[0053] The image forming section 20 as an example of an image forming member includes 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 predetermined intervals.

[0054] Each image forming unit 30 includes a photosensitive drum 31 that forms an electrostatic latent image while rotating in the direction of arrow A, a charging roller 32 that charges the surface of the photosensitive drum 31, a developer 33 that serves as a developing device for developing the electrostatic latent image formed on the photosensitive drum 31, and a drum cleaner 34 that removes colorant and the like on the surface of the photosensitive drum 31.

[0055] The image forming section 20 is provided with an exposure device 26 for exposing the photosensitive drum 31 of each image forming unit 30 with a laser beam.

[0056] The exposure device 26 is not limited to the laser beam for exposure of the photosensitive drum 31. For example, a light source such as an LED (Light Emitting Diode) may be provided for each image forming unit 30, and the photosensitive drum 31 may be exposed using light emitted from the light source.

[0057] The image forming units 30 have the same structure except for the toner stored in the developer 33. The image forming units 30Y, 30M, 30C, and 30K form yellow (Y), magenta (M), cyan (C), and black (K) toner images, respectively.

[0058] The image forming units 30T and 30P form toner images using toner corresponding to the corporate color, foaming toner for Braille, fluorescent toner, gloss-enhancing toner, etc. In other words, the image forming units 30T and 30P form toner images using special color toner.

[0059] Furthermore, the image forming section 20 is provided with an intermediate transfer belt 41 for transferring the toner images of the respective colors formed on the photosensitive drums 31 of the respective image forming units 30 .

[0060] Furthermore, the image forming section 20 is provided with a primary transfer roller 42 that transfers the color toner images of the image forming units 30 onto the intermediate transfer belt 41 at the primary transfer section T1 .

[0061] The image forming section 20 is provided with a secondary transfer roller 40 that transfers the toner image transferred onto the intermediate transfer belt 41 onto the paper P at the secondary transfer section T2 .

[0062] Furthermore, the image forming section 20 is provided with a belt cleaner 45 for removing toner and the like on the surface of the intermediate transfer belt 41 , and a fixing device 80 for fixing the secondarily transferred image to the paper P.

[0063] The image forming section 20 performs an image forming operation according to a control signal from the control section 21 .

[0064] Specifically, in the image forming unit 20 , first, the image processing unit 22 performs image processing on image data input from the image reading device 4 or the PC 5 , and the image data after the image processing is supplied to the exposure device 26 .

[0065] Then, for example, in the magenta (M) image forming unit 30M, after the surface of the photosensitive drum 31 is charged by the charging roller 32 , the photosensitive drum 31 is irradiated with a laser beam modulated by image data obtained from the image processing section 22 by the exposure device 26 .

[0066] Thus, an electrostatic latent image is formed on the photosensitive drum 31 .

[0067] The formed electrostatic latent image is developed by the developer 33 , so that a magenta toner image is formed on the photosensitive drum 31 .

[0068] 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.

[0069] The toner images of the respective colors formed in the respective image forming units 30 are electrostatically transferred to the primary transfer rollers 42 in sequence. Figure 1 A toner image superimposed on the intermediate transfer belt 41 is formed on the intermediate transfer belt 41 rotating in the direction of arrow C.

[0070] The superimposed toner images formed on the intermediate transfer belt 41 are conveyed to the secondary transfer portion T2 constituted by the secondary transfer roller 40 and the backup roller 49 as the intermediate transfer belt 41 moves.

[0071] On the other hand, after being taken out from the first paper storage unit 11 by the delivery roller 15 , for example, the paper P is transported to the position of the registration roller 74 via the transport path.

[0072] When the superimposed toner images are conveyed to the secondary transfer portion T2 , the paper P is supplied from the registration roller 74 to the secondary transfer portion T2 at the timing.

[0073] Then, the superimposed toner images are electrostatically transferred onto the paper P at a secondary transfer portion T2 by the action of a transfer electric field formed between the secondary transfer roller 40 and the backup roller 49 .

[0074] Then, the paper P to which the superimposed toner images are electrostatically transferred is conveyed to the fixing device 80 .

[0075] In the fixing device 80 , the paper P on which the unfixed toner image is formed is pressed and heated, and a fixing process of the toner image on the paper P is performed.

[0076] Then, the paper P that has been subjected to the fixing process passes through a curl correction section 81 provided in the paper discharge unit 1C, and is then conveyed to a paper stacking section (not shown).

[0077] [Description of the developing device]

[0078] Next, the developing device 33 as the developing means will be described. Since the color developing devices 33 have the same structure, the following description will be given taking one developing device 33 as an example.

[0079] Figure 2 This is a diagram for explaining the developing device 33.

[0080] The developing device 33 includes a developing roller 51 for developing the electrostatic latent image on the photosensitive drum 31, a pumping roller 52 for supplying a developer to the developing roller 51, and a container 53 for containing the developer pumped up by the pumping roller 52. The developing device 33 also includes a toner bottle 57 for supplying a toner to the container 53, and a discharge path 58 for discarding the developer discharged from the container 53. The developing roller 51 functions as a developer holding body for holding the developer.

[0081] The developing roller 51 rotates while holding the developer, thereby developing the electrostatic latent image on the photosensitive drum 31. The pumping roller 52 is located on the upper side of the supply passage 56 described later in the vertical direction. Here, the vertical direction is the direction of gravity as the lower side, and the direction opposite to the direction of gravity as the upper side. The pumping roller 52 pumps up the developer in the supply passage 56 arranged along the pumping roller 52, and replenishes the developer to the developing roller 51.

[0082] The container 53 contains the developer and conveys the developer while stirring the developer. The container 53 includes a replenishment passage 54, a stirring passage 55, and a supply passage 56 as a path for conveying the developer. Figure 2In the figure, the replenishing channel 54, the stirring channel 55, and the supply channel 56 are pipes extending along the axial direction of the developing roller 51 in a direction perpendicular to the paper surface and extending to the front side and the back side of the device. The replenishing channel 54 is provided with a replenishing screw auger 540 for conveying the developer in the replenishing channel 54. The stirring channel 55 is provided with a stirring screw auger 550 for conveying the developer in the stirring channel 55, and is provided with a discharge port 68 for discharging a part of the developer to the outside and a pressure regulating port 69 for adjusting the pressure in the stirring channel 55. The discharge port 68 and the pressure regulating port 69 are openings opened on the side of the stirring channel 55, and the lower end of the opening of the pressure regulating port 69 is set on the upper side than the upper end of the opening of the discharge port 68. The connecting portion 63 for connecting to the discharge path 58 protrudes in the horizontal direction on the outer peripheral side of the pipe of the stirring channel 55. The supply channel 56 is provided with a supply auger 560 for conveying the developer in the supply channel 56.

[0083] The toner bottle 57 is connected to a developer supply port 61 (see FIG. Figure 3 ) is connected to replenish new toner in the toner bottle 57 to the replenishment channel 54.

[0084] The discharge path 58 is configured to cover the openings of both the discharge port 68 and the pressure regulating port 69 so that the developer discharged from the discharge port 68 does not leak into the image forming apparatus 1. The discharge path 58 is connected to a recovery bottle for recovering the used developer to recover the discharged developer. The discharge path 58 is fixed to the connection portion 63 by, for example, bolts or the like.

[0085] Figure 3 is a diagram for explaining the interior of the housing portion 53. Figure 2 The upper side in the up-down direction shows the internal structure of the accommodation portion 53. Figure 3 The left side is the inner side, and the right side is the front side. The replenishing screw conveyor 540, the stirring screw conveyor 550 and the supply screw conveyor 560 extend along the axial direction.

[0086] The replenishment passage 54 and the stirring passage 55 are connected at the back side of the device by a first connection passage 511 that crosses the supply passage 56, so that the developer is conveyed. In addition, the stirring passage 55 and the supply passage 56 are connected at the front side of the device by a second connection passage 512, so that the developer is conveyed.

[0087] 〔Supplementary Channel 54〕

[0088] The replenishment passage 54, which is a part of the accommodating portion 53, is provided with a developer replenishment port 61, which is an opening for replenishing new developer. The developer replenishment port 61 is connected to the toner bottle 57 (see Figure 2) is connected. The replenishing auger 540 has a rotating shaft 541 rotatably mounted in the replenishing passage 54. The rotating shaft 541 is rotatably arranged from the front side to the inner side of the replenishing passage 54. The rotating shaft 541 of the replenishing auger 540 is provided with a spiral blade 542 for conveying the developer, a reverse spiral blade 543 and an upward push paddle 544.

[0089] The spiral blade 542 conveys the developer from the front side to the back side in the axial direction as the rotating shaft 541 rotates. Figure 3 In the figure, the conveying direction is indicated as the G1 direction. The reverse spiral blade 543 pushes the developer conveyed to the inner end of the replenishing passage 54 to the front side. The push-up paddle 544 is provided at a position of the replenishing passage 54 corresponding to the first connecting passage 511, and conveys the developer to the supply passage 56 via the first connecting passage 511.

[0090] [Stirring channel 55]

[0091] As described above, the stirring passage 55 as a part of the container 53 includes the discharge port 68 and the pressure regulating port 69 (see Figure 2 ) and a stirring screw conveyor 550 for conveying the developer in the stirring passage 55.

[0092] The stirring auger 550 includes a rotating shaft 551 rotatably provided from the front side to the back side inside the stirring passage 55. The stirring auger 550 also includes a spiral blade 552, a reverse spiral blade 553, and a discharge paddle 554 for conveying the developer. The spiral blade 552, the reverse spiral blade 553, and the discharge paddle 554 are provided on the rotating shaft 551.

[0093] The spiral blade 552 is an example of a stirring conveying unit, and the reverse spiral blade 553 is an example of a reversing unit. Furthermore, the spiral blade 552 and the reverse spiral blade 553 are examples of a second conveying unit. Furthermore, the discharge paddle 554 is an example of a first conveying unit.

[0094] The spiral blade 552 conveys the developer from the inner side to the front side in the axial direction as the rotating shaft 551 rotates. Figure 3 In FIG. 1 , this transmission direction is indicated as the G3 direction.

[0095] The reverse spiral blade 553 is provided on the front side of the rotating shaft 551. The reverse spiral blade 553 conveys the developer from the front side to the back side in the axial direction as the rotating shaft 551 rotates. Figure 3 In other words, the reverse spiral blade 553 conveys the developer conveyed in one direction while being stirred by the spiral blade 552 in a direction opposite to the one direction.

[0096] The discharge paddle 554 is provided in the axial direction at a position where the reverse spiral blade 553 is provided, and is provided between the blades of the reverse spiral blade 553. The discharge paddle 554 conveys the developer toward the discharge port 68 as the rotating shaft 551 rotates. In other words, the discharge paddle 554 conveys the developer in a direction intersecting the axial direction of the rotating shaft 551.

[0097] [Supply channel 56]

[0098] The supply auger 560 of the supply passage 56 as a part of the accommodating portion 53 includes a rotating shaft 561 rotatably mounted in the supply passage 56. The supply auger 560 is provided on the rotating shaft 561, and includes a spiral blade 562, a reverse spiral blade 563, a blocking spiral blade 564, and a transfer plate 565 for conveying the developer. The spiral blade 562, the reverse spiral blade 563, the blocking spiral blade 564, and the transfer plate 565 are provided on the rotating shaft 561.

[0099] The spiral blade 562 conveys the developer from the front side to the back side in the axial direction as the rotating shaft 561 rotates. Figure 3 In the figure, the conveying direction is indicated as the G2 direction. The reverse spiral blade 563 pushes the developer conveyed to the end of the inner side of the supply passage 56 toward the front side as the rotating shaft 561 rotates. The blocking spiral blade 564 blocks the developer conveyed from the front side to the inner side by the spiral blade 562 as the rotating shaft 561 rotates, so that the developer flows to the stirring passage 55.

[0100] The transfer plate 565 is provided at a position corresponding to the first connection passage 511 , and transfers the developer to the stirring passage 55 as the rotation shaft 561 rotates.

[0101] [Description of the exhaust port 68 and the pressure regulating port 69]

[0102] Next, use Figures 4 to 6 The discharge port 68 and the pressure regulating port 69 to which this embodiment is applied will be described.

[0103] Figure 4 It is a perspective view showing the end side of the front of the accommodation portion 53 extending in the axial direction. Here, the through hole 64 and the blocking portion 65 of the connection portion 63 are shown.

[0104] Figure 5 It means in Figure 4 A perspective view of the state in which the sealing portion 65 is removed.

[0105] Figure 6 It is a detailed representation Figure 4 A diagram of the sealing portion 65 is shown.

[0106] like Figure 4As shown, a channel for connecting with the discharge path 58 (reference Figure 2 ) is provided. The connection portion 63 is protrudingly provided on the outer surface of the stirring channel 55, and has a thickness extending from the outer surface of the stirring channel 55 toward the outside in the discharge direction. In addition, the connection portion 63 includes a through hole 64 connecting the stirring channel 55 and the discharge path 58. In addition, the connection portion 63 includes a blocking portion 65 that blocks a portion of the through hole 64. The through hole 64 and the blocking portion 65 form a discharge port 68 and a pressure regulating port 69.

[0107] like Figure 5 As shown, the through hole 64 includes an inner opening 641 as an opening on the stirring passage 55 side and an outer opening 642 as an opening on the discharge path 58 side. The inner opening 641 is an example of a common opening as an opening provided in the stirring passage 55 constituting a part of the accommodating portion 53. Figure 5 When viewed from the outside in the discharge direction to the inside, the shapes of the inner opening 641 and the outer opening 642 are rectangular.

[0108] The through hole 64 has, for example, four inner surfaces. The lower inner surface 643, which is the inner surface on the lower side of the four inner surfaces, is formed by an inclined surface extending downward toward the outside so that the through hole 64 expands from the inside of the stirring passage 55 toward the outside. The upper inner surface 644, which is the inner surface on the upper side of the four inner surfaces, is a surface parallel to the horizontal plane. The first inner surface 645 on the axial inner side and the second inner surface 646 on the axial front side are arranged to be opposite to each other.

[0109] Next, the sealing portion 65 (refer to Figure 4 ) is formed to block a part of the inside of the through hole 64. The blocking portion 65 is provided to be replaceable. In addition, the blocking portion 65 can change the position or shape or the position and shape of the discharge port 68 and the pressure adjustment port 69 provided in the connecting portion 63 according to the characteristics of the developer accommodated in the accommodating portion 53.

[0110] exist Figure 6 In the example shown, the blocking portion 65 has a lower surface 652 arranged along the slope of the lower inner surface 643 of the through hole 64. In addition, the width of the blocking portion 65 is made to be substantially the same as the width of the through hole 64. The height of the blocking portion 65 is shorter than the height of the outer opening 642 of the through hole 64, so that when the lower surface 652 is brought into contact with the lower inner surface 643, the blocking portion 65 can be formed in a manner such as Figure 4 A gap is formed at the upper portion of the through hole 64 shown. The gap is a pressure adjustment port 69. The air in the stirring passage 55 is discharged to the outside of the stirring passage 55 through the gap, thereby adjusting the pressure inside the stirring passage 55.

[0111] Furthermore, the upper surface 651 of the sealing portion 65 is an inclined surface extending upward from the inside of the stirring passage 55 toward the outside when the sealing portion 65 is disposed in the through hole 64. Figure 3 ) is splashed, and the developer passes through the pressure adjustment port 69 and is located on the upper surface 651. In this case, the developer carried on the upper surface 651 moves toward the stirring passage 55 which is a part of the accommodating portion 53 by falling along the inclined surface. Figure 6 In the figure, the sealing portion 65 has a recessed portion 658 whose lower right portion is recessed. When the sealing portion 65 is fitted into the through hole 64, a gap formed by the recessed portion 658 and the through hole 64 becomes a discharge port 68 for discharging the developer.

[0112] [Regarding the positional relationship between the discharge port, pressure regulating port, and discharge paddle]

[0113] Next, use Figure 7 , Figure 8 The positional relationship among the discharge paddle 554 , the discharge port 68 , and the pressure regulating port 69 will be described. Figure 7 is from Figure 4 VII direction of the interior of the stirring channel 55 is observed schematically, which is a diagram for explaining the positional relationship between the discharge paddle 554, the discharge port 68 and the pressure regulating port 69 in the axial direction. Figure 8 Yes means Figure 3 The diagram of a part of the VIII-VIII cross section of FIG. 5 is a diagram for explaining the positional relationship among the discharge paddle 554 , the discharge port 68 , and the pressure regulating port 69 in a direction intersecting the axial direction.

[0114] like Figure 7 and Figure 8 As shown, the discharge paddle 554 is a plate-shaped member provided on the rotating shaft 551, and the shape of the plate surface of the discharge paddle 554 is a rectangular shape. One surface of the discharge paddle 554 is installed to face the surface of the rotating shaft 551. The surface of the plate surface of the discharge paddle 554 facing the surface of the rotating shaft 551 is a discharge surface 554a, which functions as a conveying surface for conveying the developer in a direction intersecting the axial direction. The discharge surface 554a is provided to extend along the tangent direction of the cross-sectional circle of the rotating shaft 551.

[0115] like Figure 7As shown, the discharge paddle 554 is disposed between the blades of the reverse spiral blade 553 in the axial direction. Here, the direction in which the developer is conveyed by the reverse spiral blade 553 is from the front side to the back side, which is the opposite direction to the direction in which the developer is conveyed by the spiral blade 552. Therefore, the developer conveyed by the reverse spiral blade 553 adheres to the back side surface of the reverse spiral blade 553. Therefore, in order to discharge more developer, the discharge paddle 554 is installed at a position close to the back side surface of the reverse spiral blade 553 (that is, the front side of the pitch of the reverse spiral blade 553). In more detail, if the length from the axial center of the discharge paddle 554 to the surface of the reverse spiral blade 553 on the front side in the axial direction is set to L1, and the length to the surface of the reverse spiral blade 553 on the back side in the axial direction is set to L2, then L1<L2, and the discharge paddle 554 as the first conveying part is arranged to be biased toward the side of the surface of the reverse spiral blade 553 as the second conveying part that conveys the developer.

[0116] As described above, the discharge paddle 554 is arranged to be biased toward the front side in the axial direction, but there is a gap between the blade of the reverse spiral blade 553 and the discharge paddle 554. The developer between the blade of the reverse spiral blade 553 and the discharge surface 554a of the discharge paddle 554 falls from the discharge surface 554a through the gap, thereby suppressing the fluctuation of the amount of developer carried on the discharge surface 554a.

[0117] Furthermore, the length from the center of the rotating shaft of the rotating shaft 551 to the end of the discharge paddle 554 is shorter than the length from the center of the rotating shaft of the rotating shaft 551 to the end of the reverse spiral blade 553. In other words, the end of the discharge paddle 554 is located closer to the center of the rotating shaft than the end of the reverse spiral blade 553. Thus, the developer is suppressed from being discharged from the pressure regulating port 69.

[0118] The discharge port 68 is provided at a position corresponding to the position where the discharge paddle 554 is provided in the axial direction. A part of the axial position of the discharge port 68 coincides with a part of the axial position of the discharge paddle 554. In other words, the discharge port 68 is provided at a position where at least a part of the axial position overlaps with the discharge surface 554a. The discharge surface 554a of the discharge paddle 554 is located at a position corresponding to the direction in which the developer is conveyed. Thus, the discharge paddle 554 causes the developer to be discharged from the discharge port 68.

[0119] The pressure regulating port 69 is provided at a position corresponding to the position where the discharge paddle 554 is provided in the axial direction. A part of the axial position of the pressure regulating port 69 coincides with a part of the axial position of the discharge paddle 554. In other words, the pressure regulating port 69 is provided at a position where at least a part of the axial position overlaps with the discharge surface 554a. Thus, the pressure regulating port 69 suppresses the pressure fluctuation caused by the rotation of the discharge paddle 554.

[0120] And, in Figure 8 In the embodiment of the present invention, the rotating shaft 551 rotates in the clockwise direction (direction D in the figure). Furthermore, the pressure regulating port 69 is provided so that at least a portion of the pressure regulating port 69 in the axial direction is located above the discharge port 68 and downstream in the rotation direction. Thus, the pressure fluctuation caused by the discharge of the developer from the discharge port 68 can be adjusted by the pressure regulating port 69.

[0121] 〔effect〕

[0122] Next, the operation of the developing device 33 to which this embodiment is applied will be described.

[0123] First, use Figure 3 The flow of the developer circulation contained in the accommodating portion 53 is described. The new developer replenished from the developer replenishing port 61 is conveyed from the front side to the back side in the replenishing channel 54. The developer conveyed to the back side is conveyed to the stirring channel 55 via the first connecting channel 511. Then, the developer is conveyed from the back side to the front side in the stirring channel 55, and is conveyed to the supply channel 56 via the second connecting channel 512. At this time, a portion of the developer in the stirring channel 55 advances to the depth of the reverse spiral blade 553 and is discharged from the discharge port 68 to the outside of the accommodating portion 53. The developer conveyed to the supply channel 56 advances from the front side to the back side in the supply channel 56. At this time, a portion of the developer is sucked up by the pumping roller 52 (refer to Figure 2 ) is sucked up and supplied to the developing roller 51. The developer not sucked up by the sucking roller 52 is conveyed to the inner side of the supply passage 56. The developer conveyed to the inner side of the supply passage 56 is conveyed to the stirring passage 55 and circulated.

[0124] Next, use Figure 7 and Figure 8 The flow of the developer discharged from the discharge port 68 will be described.

[0125] like Figure 7 As shown, part of the developer conveyed from the inner side to the front side in the axial direction by the spiral blade 552 advances to the depth of the reverse spiral blade 553, and is conveyed from the front side to the inner side by the reverse spiral blade 553. Part of the developer conveyed to the position where the discharge paddle 554 is provided is discharged to the discharge port 68 through the discharge surface 554a of the discharge paddle 554. Figure 8 In FIG. 6 , the flow of the developer discharged from the discharge port 68 is indicated by an arrow G5 .

[0126] Next, use Figure 8 The flow of the air exhausted from the pressure regulating port 69 will be described.

[0127] The discharge paddle 554 has a discharge surface 554a facing a direction intersecting the rotation axis 551 in order to convey the developer to the discharge port 68. The discharge surface 554a not only moves the developer but also moves the air in the stirring channel 55 in a direction intersecting the rotation axis 551. Therefore, the discharge paddle 554 may become a factor of pressure fluctuation of the air in the stirring channel 55. Here, the pressure regulating port 69 is provided at the upper part of the discharge port 68 and a part of the air moving through the discharge surface 554a flows toward the pressure regulating port 69 in the direction faced by the discharge surface 554a. The air flowing to the pressure regulating port 69 flows out to the discharge path 58 which is the outside of the stirring channel 55 through the through hole formed by the connecting portion 63 and the sealing portion 65. Figure 8 In FIG. 6 , the flow of air flowing out from the pressure regulating port 69 is indicated by arrow K.

[0128] The air flows out from the pressure regulating port 69, so that the pressure fluctuation caused by the discharge paddle 554, which may be a factor of the pressure fluctuation, can be suppressed. That is, the pressure fluctuation around the discharge port 68 provided at the position corresponding to the discharge paddle 554 can be suppressed.

[0129] As described in detail above, in this embodiment, the discharge paddle 554 conveys the developer to the discharge port 68 to suppress the variation of the discharge amount due to the fluidity of the developer, and the pressure regulating port 69 is provided to suppress the variation of the discharge amount due to the pressure variation generated by the discharge paddle 554.

[0130] [Note]

[0131] (1) A developing device comprising:

[0132] A developer holding body for holding the developer;

[0133] a containing portion for containing the developer supplied to the developer holding body;

[0134] A rotating shaft, rotatably disposed inside the accommodating portion;

[0135] a first conveying portion disposed on the rotating shaft and conveying the developer in a direction intersecting the axial direction of the rotating shaft;

[0136] a second conveying portion, disposed on the rotating shaft and conveying the developer along the axial direction;

[0137] a discharge port provided in the housing portion and configured to discharge a portion of the developer to the outside at a position corresponding to a position where the first conveying portion is provided in the axial direction; and

[0138] The pressure regulating port is provided in the housing portion and regulates the pressure of the housing portion at a position of the discharge port in the rotational direction of the first conveying portion corresponding to a position where the first conveying portion is provided in the axial direction.

[0139] (2) The developing device according to (1), characterized in that:

[0140] The first conveying portion includes a conveying surface portion, the conveying surface portion being a surface that conveys the developer in the intersecting direction while the rotating shaft rotates.

[0141] The discharge port is disposed at a position where at least a portion of the axial direction overlaps with the conveying surface portion.

[0142] The pressure adjustment port is provided at a position where at least a portion in the axial direction overlaps with the conveying surface portion.

[0143] (3) The developing device according to (1), characterized in that:

[0144] At least a portion of the discharge port and the pressure regulating port in the axial direction overlap with each other in the rotational direction of the first conveying unit.

[0145] (4) The developing device according to any one of (1) to (3), characterized in that:

[0146] The second conveying portion includes: a stirring conveying portion for conveying the developer in one direction while stirring the developer; and a reversing portion provided at an end portion in the axial direction of the rotating shaft and for conveying the developer conveyed in one direction by the stirring conveying portion in a direction opposite to the one direction.

[0147] The first transmission portion is provided at a position where the direction changing portion is arranged in the axial direction.

[0148] (5) The developing device according to any one of (1) to (3), characterized in that:

[0149] The second conveying part is a blade spirally arranged on the rotating shaft.

[0150] The first conveying portion is provided between the spiral blades.

[0151] (6) The developing device according to (5), characterized in that:

[0152] The first conveying portion is disposed between the blades and is disposed so as to be biased toward a surface side of the blades that conveys the developer.

[0153] (7) The developing device according to (6), characterized in that:

[0154] There is a gap between the blade and the first conveying portion.

[0155] (8) The developing device according to any one of (5) to (7), characterized in that:

[0156] The tip of the first conveying portion is located closer to the center of the rotation shaft than the tip of the blade.

[0157] (9) The developing device according to (1), characterized in that:

[0158] The opening of the discharge port and the opening of the pressure adjustment port are formed by a common opening which is one opening provided in the accommodation portion and a blocking portion which blocks a part of the common opening.

[0159] (10) The developing device according to (9), characterized in that:

[0160] The blocking portion changes the position and / or shape of the discharge port and the pressure adjustment port according to the characteristics of the developer accommodated in the accommodation portion.

[0161] (11) The developing device according to (9), characterized in that:

[0162] The blocking portion has a slope that moves the developer entering the opening of the pressure regulating port toward the accommodating portion.

[0163] (12) An image forming apparatus comprising the developing device according to any one of (1) to (11),

[0164] An image is formed on a recording material by developing the electrostatic latent image formed by the photoreceptor with the developer whose charge is stabilized by the developing device.

[0165] According to the developing device of (1), variation in the amount of developer discharged is suppressed.

[0166] According to the developing device of (2), compared with a case where the conveying surface portion is not provided, the developer amount is stably discharged, thereby suppressing the variation in the developer amount.

[0167] According to the developing device of (3), compared with a case where the discharge port and the pressure regulating port do not partially overlap, the flow of air becomes better and the pressure is better regulated.

[0168] According to the developing device of (4), when the amount of developer in the accommodating portion increases, the developer is discharged quickly.

[0169] According to the developing device of (5), the developer can be discharged by utilizing a mechanism for conveying the developer by a blade.

[0170] According to the developing device of (6), the developer discharge amount is increased compared to the case where the first conveying portion is provided away from the surface of the blade that conveys the developer.

[0171] According to the developing device of (7), the variation in the amount of developer discharged is suppressed compared to a case where there is no gap between the blade and the first conveying portion.

[0172] According to the developing device of (8), compared with a case where the distal end of the first conveying portion protrudes further than the distal end of the blade, it is possible to suppress the developer from being discharged from the pressure regulating port.

[0173] According to the developing device of (9), the shape of the discharge port and the shape of the pressure regulating port can be easily changed.

[0174] According to the developing device of (10), variation in the amount of developer discharged is suppressed depending on the type of developer.

[0175] According to the developing device of (11), the outflow of air from the pressure adjustment port is allowed, while the discharge of the developer is suppressed.

[0176] According to the image forming apparatus of (12), the quality of the image formed on the recording material is improved.

[0177] The above-mentioned embodiments of the present invention are provided for the purpose of illustration and description. In addition, the embodiments of the present invention do not fully and exhaustively include the present invention, and do not limit the present invention to the disclosed methods. Obviously, various modifications and changes are self-evident to those skilled in the art to which the present invention belongs. The present embodiment is selected and described in order to most easily understand the principles of the present invention and its application. Thus, other technicians in the art can understand the present invention through various variations optimized for specific uses assumed to be various embodiments. The scope of the present invention is defined by the above claims and their equivalents.

Claims

1. A developing device comprising: A developer holding body for holding the developer; a containing portion for containing the developer supplied to the developer holding body; A rotating shaft, rotatably disposed inside the accommodating portion; a first conveying portion disposed on the rotating shaft and conveying the developer in a direction intersecting the axial direction of the rotating shaft; a second conveying portion, disposed on the rotating shaft and conveying the developer along the axial direction; a discharge port provided in the housing portion and discharging a portion of the developer to the outside at a position corresponding to a position where the first conveying portion is provided in the axial direction; and The pressure regulating port is provided in the housing portion and regulates the pressure of the housing portion at a position of the discharge port in the rotational direction of the first conveying portion corresponding to a position where the first conveying portion is provided in the axial direction.

2. The developing device according to claim 1, characterized in that: The first conveying portion includes a conveying surface portion, the conveying surface portion being a surface that conveys the developer in the intersecting direction while the rotating shaft rotates. The discharge port is disposed at a position where at least a portion of the axial direction overlaps with the conveying surface portion. The pressure adjustment port is provided at a position where at least a portion in the axial direction overlaps with the conveying surface portion.

3. The developing device according to claim 1, characterized in that: At least a portion of the discharge port and the pressure regulating port in the axial direction overlap with each other in the rotational direction of the first conveying unit.

4. The developing device according to any one of claims 1 to 3, characterized in that: The second conveying portion includes: a stirring conveying portion for conveying the developer in one direction while stirring the developer; and a reversing portion provided at an end portion in the axial direction of the rotating shaft and for conveying the developer conveyed in one direction by the stirring conveying portion in a direction opposite to the one direction. The first transmission portion is provided at a position where the direction changing portion is arranged in the axial direction.

5. The developing device according to any one of claims 1 to 3, characterized in that: The second conveying part is a blade spirally arranged on the rotating shaft. The first conveying portion is provided between the spiral blades.

6. The developing device according to claim 5, characterized in that: The first conveying portion is disposed between the blades and is disposed so as to be biased toward a surface side of the blades that conveys the developer.

7. The developing device according to claim 6, characterized in that: There is a gap between the blade and the first conveying portion.

8. The developing device according to any one of claims 5 to 7, characterized in that: The tip of the first conveying portion is located closer to the center of the rotation shaft than the tip of the blade.

9. The developing device according to claim 1, characterized in that: The opening of the discharge port and the opening of the pressure adjustment port are formed by a common opening which is one opening provided in the accommodation portion and a blocking portion which blocks a part of the common opening.

10. The developing device according to claim 9, characterized in that: The blocking portion changes the position and / or shape of the discharge port and the pressure adjustment port according to the characteristics of the developer accommodated in the accommodation portion.

11. The developing device according to claim 9, characterized in that: The blocking portion has a slope that moves the developer entering the opening of the pressure regulating port toward the accommodating portion.

12. An image forming apparatus comprising the developing device according to any one of claims 1 to 11, An image is formed on a recording material by developing the electrostatic latent image formed by the photoreceptor with the developer whose charge is stabilized by the developing device.

Images