Developing device

Abstract

To provide a developing device comprising a regulation blade having a regulation part in contact with a surface of a developing roller and end seals in contact with the regulation part in a rotation axis direction of the developing roller, and to increase adhesion between the end seals and the regulation part.SOLUTION: A regulation blade has a plate-like member, and a regulation member having a regulation part that is formed with concave parts recessed compared with a center part at the ends in a first direction. The concave parts each extend in the first direction and are each connected with a first surface of the regulation part extending in a second direction. Seal members are in contact with end faces of the regulation part. The plate-like member is welded to a support plate along the first direction to form welding traces. The welding traces are intermittently formed, and (i) are on the other end side in the second direction, and (ii) overlap a center part of the regulation member and an area inside an end face of the seal member and outside the first surface at each of the ends in the first direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a developing device used in an image forming apparatus. [Background technology]

[0002] The developing device used in the image forming apparatus has the following configuration.

[0003] The developing device has a rotatable developing member that carries developer on its surface, and a regulating blade that regulates the thickness of the layer of developer carried on the surface of the developing member, with a flexible regulating portion made of rubber, resin, or other material formed at the tip of the regulating blade.Patent Document 1 discloses a developing device that includes a seal member that contacts the regulating portion in the direction of the rotation axis of the developing member and is disposed between the developing member and the regulating blade.

[0004] In such a developing device, the seal member is in close contact with the restricting portion, thereby preventing developer from leaking out of the developing device at both ends of the restricting portion in the direction of the rotation axis of the developing member. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-60033 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the configuration of Patent Document 1 has the following problem: In such a developing device, if the seal member and the regulating portion are not in sufficient contact with each other in the direction of the rotation axis of the developing member, there is a possibility that the developer may leak from between the seal member and the regulating portion.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to improve the adhesion between the seal member and the regulating portion in the developing device. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the developing device according to the present application is a developing device used in an image forming apparatus, and includes a developing frame that accommodates developer, a rotatable developing member that carries the developer, a regulating blade that is fixed to the developing frame and regulates the developer carried on the surface of the developing member, and a sealing member that seals to prevent the developer from leaking outside the developing frame, and the regulating blade has a support plate that extends in a first direction that is the direction of the rotation axis of the developing member, and a seal member that seals the developer at one end in a second direction that is a direction intersecting with the first direction. a plate-like member disposed to face the developing member and supported by the support plate at its other end in a direction intersecting the first direction; and a regulating member for regulating the developer carried on the surface of the developing member, the regulating member being fixed at its one end to a facing surface of the plate-like member facing the developing member, in contact with the developing member, and having a regulating portion at its end in the first direction that is recessed in a direction from the one end toward the other end more than a central portion, the regulating member being formed inside the end of the plate-like member in the first direction, The recess extends in the first direction and is connected to a first surface of the regulating portion extending in the second direction, the sealing member is fixed to the opposing surface of the plate-shaped member, is arranged alongside the regulating portion at the end of the plate-shaped member in the first direction, is in contact with the end surface of the regulating portion when the developing member is in contact with the regulating portion, and is arranged between the plate-shaped member and the developing member in a third direction that intersects the first direction and the second direction, the plate-shaped member is welded to the support plate along the first direction to form weld marks, the weld marks are formed intermittently, and the weld marks i) are on the other end side in the second direction, and ii) overlap with the central portion of the regulating member and an area inside the end surface of the sealing member at the end and outside the first surface in the first direction. [Effects of the Invention]

[0009] This can improve the adhesion between the seal member and the regulating portion in the developing device. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a perspective view of a regulating blade according to the first embodiment. [Figure 2] FIG. 1 is a cross-sectional view of an image forming apparatus according to a first embodiment. [Figure 3] FIG. 1 is a perspective view of an image forming apparatus according to a first embodiment. [Figure 4] FIG. 2 is a perspective view of a cartridge tray and a developing cartridge according to the first embodiment. [Figure 5] FIG. 2 is a cross-sectional view of the developing cartridge and the drum unit according to the first embodiment. [Figure 6] FIG. 2 is an exploded perspective view of the developing cartridge according to the first embodiment. [Figure 7] FIG. 2 is an explanatory diagram of a developing cartridge according to the first embodiment. [Figure 8] FIG. 2 is a cross-sectional view of the developing cartridge according to the first embodiment. [Figure 9] FIG. 2 is a perspective view of a regulating blade according to the first embodiment. [Figure 10] FIG. 2 is an explanatory diagram of a regulating blade according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] The following detailed description of the embodiments of the present invention will be given with reference to the accompanying drawings. However, the functions, materials, shapes, relative positions, etc. of the components described in the embodiments are not intended to limit the scope of the present invention unless otherwise specified. Furthermore, the functions, materials, shapes, etc. of components that have already been described in the following description are the same as those described in the initial description unless otherwise specified.

[0012] In the following description, the direction in which the axis of the developing roller extends will be referred to as the "first direction," "longitudinal direction," "rotational axis direction," or "longitudinal." A direction intersecting the first direction, which is the vertical direction when the image forming apparatus is installed on a horizontal surface, will be referred to as the "second direction." A direction intersecting the first and second directions will be referred to as the "third direction." The first and second directions intersect, preferably perpendicular to each other. The second and third directions intersect, preferably perpendicular to each other. The third direction intersects, preferably perpendicular to the first direction. In the following description, the side of the image forming apparatus where the front door is provided will be referred to as the front side, and the side opposite the front side will be referred to as the rear side. When viewing the image forming apparatus from the front side, the left side will be referred to as the drive side, and the right side will be referred to as the non-drive side. [Example]

[0013] A developing device according to a first embodiment of the present invention will be described with reference to the drawings.

[0014] <Configuration of image forming apparatus> First, the configuration of the image forming apparatus will be described. Fig. 2 is a cross-sectional view of the image forming apparatus 1 according to this embodiment. Fig. 3 is a perspective view of the image forming apparatus 1 according to this embodiment, with Fig. 3(a) showing the image forming apparatus 1 with the front door 40 open and the cartridge tray 3 pulled out, and Fig. 3(b) showing the cartridge tray 3 hidden. Fig. 4 is a perspective view of the cartridge tray 3 and the developing cartridge 8, which is the developing device, according to this embodiment. Fig. 5 is a cross-sectional view of the developing cartridge 8 and drum unit 30 according to this embodiment.

[0015] 2 and 5 are cross-sectional views taken along a direction perpendicular to the rotational axis of the developing roller 6, which is a developing member.

[0016] The image forming apparatus 1 shown in FIG. 2 is a color laser printer using an electrophotographic image forming process. It forms a color image on a recording medium S (e.g., printing paper) using a developer (e.g., toner) supplied from developing cartridges 8 (8Y, 8M, 8C, and 8K) that serve as developing devices. In this embodiment, a color image is formed using four photosensitive drums 4 (4Y, 4M, 4C, and 4K) and four developing cartridges 8 (8Y, 8M, 8C, and 8K). The four developing cartridges 8 contain developers of different colors (e.g., yellow, cyan, magenta, and black). The number of developing cartridges 8 and photosensitive drums 4 may be one to three, or five or more, depending on the number of colors used. In this embodiment, the configurations and operations of the photosensitive drums 4 (4Y, 4M, 4C, and 4K) and developing cartridges 8 (8Y, 8M, 8C, and 8K) are substantially the same, except for the colors of the images they form. Therefore, hereinafter, unless a distinction is particularly required, the Y, M, C, and K will be omitted and a general description will be given. That is, in this embodiment, the image forming apparatus 1 has, as a plurality of image carriers, four photosensitive drums 4 arranged side by side in a direction intersecting the vertical direction and developing cartridges 8.

[0017] The image forming apparatus 1 is composed of an image forming apparatus main body 2 (hereinafter referred to as the “apparatus main body 2”), a cartridge tray 3 having a photosensitive drum 4 and detachable from the apparatus main body 2, and a developing cartridge 8 detachable from the cartridge tray 3.

[0018] The apparatus main body 2 has an exposure device 10, an electrostatic transfer device 11, a paper feed unit 18, a fixing device 21, a discharge unit 22, and a front door 40.

[0019] The exposure device 10 is provided above the developing cartridges 8 and the cartridge tray 3, and outputs laser light L corresponding to image information. The laser light L scans and exposes the surfaces of the photosensitive drums 4 (4Y, 4M, 4C, 4K).

[0020] A developing cartridge 8 is provided as a developing device for developing a developer onto the scanned and exposed surface of the photosensitive drum 4. The developing process by which a developer image is formed on the surface of the photosensitive drum 4 will be described later.

[0021] The electrostatic transfer device 11 is located below the developer cartridges 8 and the cartridge tray 3. It includes a transfer belt 12 that circulates and faces all of the photosensitive drums 4, facing and in contact with them. The transfer belt 12 is made of a resin film or a multilayer film material with a resin layer on a rubber base layer. The transfer belt 12 is stretched over a drive roller 13 and a driven roller 14. The transfer belt 12 electrostatically attracts the recording medium S to its outer peripheral surface (upper side in FIG. 2 ) and circulates to bring the recording medium S into contact with the photosensitive drums 4. This transports the recording medium S toward the photosensitive drums 4. A transfer roller 16 is provided in parallel with the inside of the transfer belt 12, facing the photosensitive drums 4. A predetermined bias is applied to the transfer rollers 16 during transfer, and an electric charge is applied to the recording medium S via the transfer belt 12. The resulting electric field transfers the developer image on the photosensitive drum 4 to the recording medium S in contact with the photosensitive drum 4.

[0022] The paper feed unit 18 is provided below the electrostatic transfer device 11. The paper feed unit 18 has a paper feed tray 19 on which recording media S are stacked and stored, and a paper feed roller 20.

[0023] The fixing device 21 and the discharge unit 22 are provided above the apparatus main body 2. The fixing device 21 fixes the developer image transferred onto the recording medium S by applying heat and pressure, and the discharge unit 22 discharges the recording medium S that has passed through the fixing device 21 onto a discharge tray 23.

[0024] The cartridge tray 3 has a drum unit 30 provided with photosensitive drums 4 corresponding to the four developing cartridges 8. Furthermore, as shown in FIG. 5, the drum unit 30 includes a drum frame 27 and a charging device 5.

[0025] As shown in FIG. 3, the cartridge tray 3 is configured to be able to be pulled out toward the front side in the third direction along a tray pull-out rail 41 provided on the image forming apparatus 1 after the front door 40 of the image forming apparatus 1 is opened.

[0026] 5, the developer cartridge 8 has a development frame 28 that contains developer, and a development roller 6 that carries developer on its surface and is rotatable about a rotation axis extending in the first direction. The developer cartridge 8 also has a supply roller 26 that supplies developer to the development roller 6, and a layer thickness regulating blade 72 that contacts the surface of the development roller 6 to regulate the layer thickness of the developer carried on the surface of the development roller 6.

[0027] 4, the developer cartridge 8 is detachable in the second direction relative to the cartridge tray 3. As an example, FIG. 4 shows a state in which the developer cartridge 8C has been removed from the cartridge tray 3. In this way, the developer cartridges 8 are detachable from and attached to the four slots provided in the cartridge tray 3, and the developer cartridges 8 can be replaced depending on the usage situation.

[0028] <Image formation process> Next, the image forming process will be described with reference to FIGS.

[0029] During the image formation process, the photosensitive drum 4 is rotated in the direction of arrow D at a predetermined speed. The transfer belt 12 of the electrostatic transfer device 11 is also rotated in the direction of arrow C at a speed corresponding to the speed of the photosensitive drum 4. First, the surface of the photosensitive drum 4 is uniformly charged to a predetermined polarity and potential by the charging device 5. Then, the exposure device 10 outputs laser light L corresponding to the image signal for each color, and scans and exposes the surface of each photosensitive drum 4. As a result, an electrostatic latent image corresponding to the image signal for each color is formed on the surface of each photosensitive drum 4.

[0030] The developer in the developing frame 28 is carried by the developing roller 6, which is driven to rotate in the direction of arrow E at a predetermined speed. The developer carried by the developing roller 6 is supplied to the surface of the developing roller 6 by the supply roller 26. The developer supplied to the developing roller 6 then enters between the developing roller 6 and the layer thickness regulating blade 72 and is carried on the developing roller 6 as a thin layer of a uniform thickness. The developer carried on the developing roller 6 is then supplied to the electrostatic latent image formed on the photosensitive drum 4. As a result, the developer adheres to the electrostatic latent image and develops it (makes it visible), forming a developer image on the surface of the photosensitive drum 4. In this embodiment, the developer polarity is positive. Therefore, a voltage of positive polarity compared to the potential of the electrostatic latent image formed on the surface of the photosensitive drum 4 is applied to the developing roller 6 from a development power source (not shown). With the above settings, the positively charged developer moves from the developing roller 6 to the electrostatic latent image formed on the photosensitive drum 4.

[0031] Furthermore, the recording media S are separated and fed one by one at a predetermined controlled timing. The leading edge of the developer image on the surface of the first photosensitive drum 4Y of the recording medium S moves to the transfer section, which is the point facing the transfer belt 12. The timing at which the recording media S is transported to the transfer section is synchronized with the rotation of the photosensitive drum 4, and the recording media S is transported to the transfer belt 12 at a predetermined controlled timing so that the printing start positions at the transfer section coincide. The developer images on each photosensitive drum 4 are sequentially transferred onto the recording media S electrostatically attracted to the transfer belt 12 by an electric field formed between each photosensitive drum 4 and the transfer roller 16. At this time, a negative voltage, which is the opposite polarity to the positive polarity, is applied to the transfer roller 16 from a transfer power source (not shown). This makes it possible to electrically attract the positive developer toward the recording media S.

[0032] The recording medium S onto which the four-color developer images have been transferred is separated from the transfer belt 12 and transported to the fixing device 21. The developer images are thermally fixed onto the recording medium S by the fixing device 21. Thereafter, the recording medium S is discharged onto a discharge tray 23 by a discharge unit 22.

[0033] Furthermore, the developer remaining on the photosensitive drum 4 without being transferred is collected in the developing cartridge 8 and reused. Specifically, the photosensitive drum 4 is once positively charged by the charging device 5, and the surface potential of the photosensitive drum 4 is made higher on the positive side than the voltage applied to the developing roller 6. As a result, when the positively charged residual developer on the surface of the photosensitive drum 4 moves to the portion facing the developing roller 6, the residual developer is electrically collected inside the developing frame 28.

[0034] <Detailed structure of the drum unit and developing cartridge> 5 and 6, the detailed configurations of the drum unit 30 and the developing cartridge 8 will be described. Figure 6 is an exploded perspective view of the developing cartridge 8 according to this embodiment, with the attachment directions of the respective parts indicated by arrows.

[0035] As shown in FIG. 5, the drum unit 30 includes the photosensitive drum 4, the drum frame 27, and the charging device 5, as described above. The photosensitive drum 4 is attached to the drum frame 27 so as to be rotatable about a rotation axis extending in the first direction. A drum input coupling 54 for transmitting a driving force to the photosensitive drum 4 is provided on the driving side of the photosensitive drum 4 (FIG. 4). The drum input coupling 54 is configured to receive a driving force from the apparatus main body 2 and transmit it to the photosensitive drum 4 by engaging with a drum drive coupling 52 (FIG. 3(b)) of the apparatus main body 2. The charging device 5 is provided along the first direction and is supported by the drum frame 27 in close proximity to the photosensitive drum 4. The charging device 5 is electrically connected to the apparatus main body 2.

[0036] As described above, the developer cartridge 8 includes the developing frame 28 that accommodates the developer, the developing roller 6, the supply roller 26 that supplies the developer to the developing roller 6, and the regulating blade 72 that regulates the thickness of the developer carried on the surface of the developing roller 6. As shown in FIG. 6, the developer cartridge 8 also includes a fixing screw 99, an agitating member 88, a drive-side bearing member 70, a side cover 68, and a non-drive-side bearing member 71. The developer cartridge 8 also includes a development gear 61, a supply gear 63, a development input gear 62, an agitating gear 65, and an idler gear 64 for driving the various components of the developer cartridge 8. Details will be described later.

[0037] The developing roller 6 is a roller that can rotate in the direction of arrow E on a rotation axis extending in the first direction, as shown in FIG. 5, and is composed of a roller body and a roller shaft. The roller body is made of, for example, elastic rubber or a sponge member. The roller shaft is made of, for example, conductive metal or resin. A developing gear 61 is connected to the drive side end of the roller shaft. The supply roller 26 contacts the developing roller 6 to supply developer to the surface of the developing roller 6, and is rotatable on the rotation axis extending in the first direction. The supply roller 26 is made of a roller body and a roller shaft, and the roller body is made of, for example, elastic rubber or a sponge member. The roller shaft is made of, for example, conductive metal or resin. A supply gear 63 is connected to the drive side end of the roller shaft.

[0038] The configuration of the regulating blade 72 will be described with reference to Figure 6. The regulating blade 72 comes into contact with the developing roller 6 and regulates the thickness of the developer carried on the surface of the developing roller 6. The regulating blade 72 is composed of a support plate 73, a blade portion 74, and a regulating portion 75.

[0039] The support plate 73 is a metal member that supports the blade portion 74, and has a substantially rectangular first plate-shaped portion 73a that faces the blade portion 74 and extends in the first direction, and a second plate-shaped portion 73b that extends from the first plate-shaped portion 73a in a direction intersecting the blade portion 74. The first plate-shaped portion 73a has protruding portions 73e at both ends in the first direction that protrude in a direction perpendicular to the first direction and away from the developing roller 6, and the protruding portions 73e are provided with through-holes 73c that penetrate in the thickness direction. The second plate-shaped portion 73b is provided with positioning grooves 73d that are elongated groove-shaped.

[0040] The blade portion 74 is a substantially rectangular metal plate-like member extending in the first direction. It is disposed so that a tip end 74a, which is one end in a direction intersecting the first direction, faces the developing roller 6. It is fixed to the first plate-like portion 73a of the support plate 73 by welding at a base end 74b, which is the other end in a direction intersecting the first direction, to form a fixed portion W, which is a weld mark. Blade ends 74e are provided at both ends in the first direction. The blade portion 74 is thinner than the support plate 73, allowing it to elastically deform when it comes into contact with the developing roller 6. It comes into contact with the developing roller 6 using the restoring force generated by elastic deformation, thereby regulating the thickness of the developer carried on the surface of the developing roller 6.

[0041] Furthermore, a round hole 74c and an elongated hole 74d are formed at both ends of the blade portion 74 in the first direction, and a round hole 73f and an elongated hole 73g are also formed at corresponding positions in the first plate-shaped portion 73a of the support plate 73. When the blade portion 74 is fixed to the support plate 73, these round holes 74c and 73f, and the elongated holes 74d and 73g are positioned by passing an assembly jig through the respective holes and then fixed. This improves the positioning accuracy of the relative positions of the support plate 73 and the blade portion 74. In this embodiment, holes are formed in each of the support plate 73 and the blade portion 74. However, it is also possible to have one of the components shaped as a hole and the other as a protrusion, and to regulate the relative positions between the components by engaging the hole and the protrusion with each other.

[0042] The regulating portion 75 is a generally rectangular regulating member extending in the first direction and formed inside the blade end 74e of the blade portion 74 in the first direction. The regulating portion 75 is a flexible regulating member made of a rubber material such as silicone rubber or urethane rubber, or a resin material. The regulating portion 75 has a first surface 75a (FIG. 5) that faces the blade portion 74 and is fixed to the tip end 74a, and a second surface 75b that faces the developing roller 6 and contacts the surface of the developing roller 6. The corners of the second surface 75b on the tip side of the regulating blade 72 have an arc-shaped cross section when viewed from the first direction (FIG. 5). The regulating portion 75 also has notches 75d at both ends in the first direction. The notches 75d are recessed from the tip end of the regulating blade 72 toward the base end 74b and recessed inward in the first direction from both ends 75c of the regulating portion 75 at the first direction. The corner of the regulating blade 72 of the regulating portion 75 on the tip side where the notch 75d is formed has a cross-sectional shape that is approximately right-angled when viewed from the first direction. The developing roller 6 rotates in the direction of arrow E while rubbing against the regulating portion 75 (FIG. 5). Therefore, the corner of the regulating blade 72 on the tip side of the regulating portion 75 on the tip side where the notch 75d is formed is more likely to scrape off developer from the developing roller 6 than the inner portion of the regulating portion 75 on the first direction where the notch 75d is not formed. Specifically, as shown in FIG. 5, the contact width between the developing roller 6 and the regulating portion 75 in the rotation direction of the developing roller 6 is wider in the portion where the notch 75d is not formed. On the other hand, the narrow contact width in the portion where the notch 75d is formed increases the contact pressure, making it easier to scrape off developer from the developing roller 6. Furthermore, the corner of the regulating portion 75 on the tip side where the notch 75d is not formed is arc-shaped, making it easier to guide developer toward the surface of the developing roller 6. In contrast, where the notch 75d is formed, the corner of the tip of the regulating portion 75 is approximately a right angle, making it difficult to induce the developer toward the surface of the developing roller 6 and making it easy to scrape it off.

[0043] Both ends of the regulating portion 75 in the first direction are provided with protruding portions 75e that protrude more than other portions in a direction perpendicular to the first direction and away from the developing roller 6. The protruding portions 75e are formed thinner than other portions of the regulating portion 75, and are closer to the blade portion 74 than the second surface 75b. The tip end 74a of the blade portion 74 has a shape that corresponds to the regulating portion 75 and the notch 75d.

[0044] The developing frame 28 accommodates the developer therein and has a blade support surface 28a facing the support plate 73 of the regulating blade 72 and a fixing hole 28b formed in the blade support surface 28a. The developing frame 28 also has a positioning rib 28c at a position corresponding to the positioning groove 73d of the support plate 73 of the regulating blade 72, and rotatably supports the agitating gear 65 and one end of the idler gear 64. The developing frame 28 and the regulating blade 72 are fixed at both ends by abutting the blade support surface 28a against the support plate 73 and engaging the positioning rib 28c with the positioning groove 73d, and fastening a fixing screw 99 through the through hole 73c into the fixing hole 28b. As shown in FIG. 5, the agitating member 88 is provided inside the developing frame 28 and is composed of a shaft portion 88a rotatable about a rotation axis extending in the first direction and a flexible sheet-like sheet portion 88b. The agitating member 88 agitates the developer in the developing frame 28 and transports the developer toward the supply roller 26. As shown in FIG. 6, the agitating gear 65 is coupled to the drive-side end of the shaft portion 88a. The drive-side bearing member 70 is fixed to the developing frame 28 on the drive side and rotatably supports the roller shaft of the developing roller 6, the roller shaft of the supply roller 26, and the developing input gear 62. The side cover 68 is fixed to the developing frame 28 on the drive side and rotatably supports the other end of the idler gear 64, and has the function of covering and protecting the supply gear 63, the developing input gear 62, the idler gear 64, and the agitating gear 65. The side cover 68 has a through-hole 68a at a position corresponding to the developing input gear 62, and the through-hole 68a exposes a coupling portion 62a of the developing input gear 62, which will be described later. The non-drive-side bearing member 71 is fixed to the developing frame 28 on the non-drive side, and rotatably supports the roller shaft of the developing roller 6 and the roller shaft of the supply roller 26. The developing input gear 62 has a coupling portion 62a for receiving a driving force by engaging with the developing drive coupling 51 (FIG. 3(b)) of the apparatus main body 2. The driving force input to the developing input gear 62 is transmitted to the developing roller 6 via the developing gear 61 and to the supply roller 26 via the supply gear 63. Similarly, the driving force input to the developing input gear 62 is transmitted to the agitator 88 via the idler gear 64 and the agitator gear 65.

[0045] <Developer sealing structure of developer cartridge> Next, the developer sealing structure of the developer cartridge 8 will be described using Figures 1, 7, 8, 9, and 10. Figure 1 is a perspective view of the regulating blade 72 according to this embodiment. Figure 7 is an explanatory diagram of the developer cartridge 8 according to this embodiment, viewed from the mounting direction of the regulating blade 72. Figure 7(a) shows the developing roller 6 and the regulating blade 72 hidden and the anti-scattering sheet 79 indicated by dashed lines, and Figure 7(b) shows the developing roller 6 and the anti-scattering sheet 79 indicated by dashed lines. Figure 8 is a cross-sectional view of the developer cartridge 8 according to this embodiment, taken along the cutting line FF in Figure 7(b) and viewed from the direction of the rotation axis of the developing roller 6. In Figure 8, the end seal member 25 is also indicated by dashed lines. Figure 9 is a perspective view of the regulating blade 72 according to this embodiment. Figure 10 is an explanatory diagram of the regulating blade 72 according to this embodiment, viewed from the thickness direction of the blade portion 74 of the regulating blade 72.

[0046] In the following explanation, the drive side will be used as an example, but the same applies to the non-drive side.

[0047] 7(a), a first seal member 76 is provided between the regulating blade 72 and the developing frame 28 in the direction of the rotation axis of the developing roller 6 (first direction). Second seal members 77 are provided between both end portions of the regulating blade 72 in the first direction and the developing frame 28. The first seal member 76 and the second seal member 77 are members including a flexible member such as a sponge, and are compressed between the developing frame 28 and the regulating blade 72 to fill the gap between the developing frame 28 and the regulating blade 72 and prevent leakage of developer.

[0048] As shown in FIG. 7B, an end seal member 25 is fixed to the blade end 74e of the blade portion 74, and is in contact with an end 75c, which is the end face of the restricting portion 75. Here, the end 75c is the outermost portion in the first direction of the second surface 75b that contacts the developing roller 6, and is in contact (close contact) with an end 25a, which is the inner end face of the end seal member 25. At least a portion of the end seal member 25 protrudes from the blade end 74e of the blade portion 74 toward the tip end 74a and is fixed to the surface of the second seal member 77 that faces the developing roller 6 (FIG. 8). The end seal member 25 is disposed between the blade portion 74 and the developing roller 6 in the thickness direction of the blade portion 74, which intersects with the first direction.

[0049] The end seal member 25 is a member including a flexible member such as a sponge, and is disposed between the blade portion 74 and the developing roller 6 and compressed to prevent leakage of developer from between the end seal member 25 and the regulating portion 75. Furthermore, at both ends of the developing roller 6 in the first direction, the second seal member 77 and the end seal member 25 are compressed to fill the gaps between the developing frame 28, the regulating blade 72, and the developing roller 6, thereby preventing leakage of developer.

[0050] Furthermore, a third seal member 78 is provided across the first direction on the developing frame 28. The third seal member 78 is a flexible sheet-like member made of a material such as PET, PPS, or PC, and is configured so that one end is attached to the developing frame 28 and the other end comes into contact with the developing roller 6 in a direction perpendicular to the first direction. The third seal member 78 bends to fill the gap between the developing frame 28 and the developing roller 6, thereby preventing leakage of developer.

[0051] Further, a scatter prevention sheet 79 is provided in the first direction near the third seal member 78. In a direction perpendicular to the first direction, one end of the scatter prevention sheet 79 is attached to the developing frame 28, and the other end extends so as to approach the developing roller 6 (FIG. 8). The scatter prevention sheet 79 receives the developer that has fallen from near the developing roller 6, thereby preventing the developer from scattering to the outside.

[0052] The fixing portion W, where the support plate 73 and the blade portion 74 are fixed by welding, is formed inward from the end portion 75c in the first direction, and is not formed outward from the end portion 75c. The fixing portion W is formed continuously along the first direction. Here, as shown in FIG. 7(b), the distance L1 between the fixing portion W and the end portion 75c in the first direction is set to 0 mm. In other words, the support plate 73 and the blade portion 74 are not fixed in the range where the blade portion 74 and the end seal member 25 overlap in the first direction. This will be described in more detail below.

[0053] In this embodiment, the definitions of "inner side" and "outer side" are as follows: the side closer to the center of the developing roller 6 and the layer thickness regulating blade 72 in the direction of the rotation axis of the developing roller 6 is "inner side", and the side farther from the center of the developing roller 6 and the layer thickness regulating blade 72 is "outer side". Unless otherwise specified, the above meanings will be used hereinafter.

[0054] 8, when the regulating blade 72 comes into contact with the developing roller 6, the blade portion 74 receives a force at the tip end 74a via the regulating portion 75 and is deformed in the direction of arrow H. Meanwhile, a restoring force acts on the fixing portion W (FIG. 7) at the base end 74b, causing the deformed blade portion 74 to return to its original shape. Here, at both ends in the first direction where the fixing portion W is not formed, the blade portion 74 is deformed in the direction of arrow J due to the restoring force and the repulsive force of the second seal member 77.

[0055] The deformation of the blade portion 74 at both ends in the first direction where the fixing portion W is not formed will be further described with reference to FIG.

[0056] The deformation of the blade portion 74 at both ends in the first direction is a combination of deformation in which the blade end portion 74e bends in the direction of arrow J along the dashed line K connecting the end portion 75c of the regulating portion 75 that contacts the developing roller 6 and the end portion of the fixed portion W, and deformation in the direction of arrow H mentioned above.

[0057] As described above, when the blade portion 74 deforms, the end seal member 25 attached to the blade portion 74 is compressed so as to bite more firmly toward the end 75c of the regulating portion 75. In other words, the end 25a of the end seal member 25 and the end 75c of the regulating portion 75 are more closely fitted to each other in the first direction. This more effectively prevents developer from leaking from between the end seal member 25 and the regulating portion 75. In this embodiment, the end 25a, which is the end face of the end seal 25, and the end 75c, which is the end face of the regulating portion 75, are always in contact with each other. However, the end 25a, which is the end face of the end seal 25, and the end 75c, which is the end face of the regulating portion 75, may be in contact with each other when the force in the direction of arrow H is applied by incorporating the developing roller 6 into the developer cartridge 8, thereby increasing the force in the direction of arrow J. In other words, the end 25a, which is the end face of the end seal 25, and the end 75c, which is the end face of the regulating portion 75, do not necessarily need to be in contact with each other when the developing roller 6 is not incorporated into the developer cartridge 8.

[0058] If the fixing portion W between the support plate 73 and the blade portion 74 were formed outward beyond the end portion 75c in the first direction, deformation of both ends of the blade portion 74 in the first direction would be restricted by the fixing portion W. As a result, the blade portion 74 would hardly deform in the direction in which the end seal member 25 and the end portion 75c of the restricting portion 75 approach each other. Therefore, the above-mentioned action is unlikely to occur.

[0059] In order to achieve the above-described effect, it is desirable to deform both ends of the blade portion 74 in the first direction more greatly. Therefore, as shown in Fig. 9(a), the distance L1 between the fixing portion W and the end 75c in the first direction may be set to be large. When set as above, the blade portion 74 deforms more greatly than when the distance L1 is set to 0 mm, and therefore the end seal member 25 fixed to the blade portion 74 can be brought into close contact with the end 75c of the restricting portion 75.

[0060] 9(b), the distance L1 between the fixing portion W and the end portion 75c in the first direction may be set to be the same as the width L2 of the notch 75d in the first direction. By setting it in this manner, the blade portion 74 deforms more than when the distance L1 is set to 0 mm, and therefore the end seal member 25 attached to the blade portion 74 can be more closely attached to the end face of the restricting portion 75.

[0061] The reason for using the configuration shown in FIG. 9(b) is that it is desirable to fix the base end 74b of the blade portion 74 to the support plate 73 in the first direction in the area where the notch 75d is not formed. In the area where the notch 75d is not formed, it is necessary to regulate the amount of developer coating required for image formation during image formation. If there is a region in the first direction where the base end 74b of the blade portion 74 is not fixed to the support plate 73, there is a concern that the contact force between the regulating blade 72 and the developing roller 6 in that region will decrease. This could result in image defects such as uneven image density in the first direction. However, by configuring the above, it is possible to suppress the decrease in contact force throughout the entire area in the first direction where the notch 75d is not formed.

[0062] In this way, as long as the distance L1 between the fixed portion W and the end portion 75c in the first direction is 0 mm or more, it may be set to any amount taking into account the contact state between the end seal member 25 and the regulating portion 75 and the contact force between the regulating blade 72 and the developing roller 6.

[0063] Based on the above, a configuration that can improve the adhesion between the end seal member 25 and the regulating portion 75 in the developer cartridge 8 will be described below. The developer cartridge 8 is used in the image forming apparatus 1 and includes a development frame 28 that contains developer, a rotatable development roller 6 that carries developer, and a regulating blade 72 that is fixed to the development frame 28 and regulates the developer carried on the surface of the development roller 6. The regulating blade 72 includes an end seal member 25 that seals to prevent the developer from leaking outside the development frame 28. The regulating blade 72 includes a support plate 73 that extends in the direction of the rotational axis of the development roller 6. The regulating blade 72 has a blade portion 74 that is a plate-like member, with one end portion, which is a tip end portion 74a in a direction intersecting the rotational axis direction, positioned to face the development roller 6 and the other end portion, which is a base end portion 74b, supported by the support plate 73. The regulating portion 75, which is a regulating member provided on the regulating blade 72, regulates the developer carried on the surface of the developing roller 6, and one end is fixed to the opposing surface of the blade portion 74 on the side facing the developing roller 6, and contacts the developing roller 6. Furthermore, the regulating portion 75 is formed inward from the blade end of the blade portion 74 in the direction of the rotation axis. The end seal member 25 is fixed to the opposing surface of the blade portion 74, and is arranged alongside the regulating portion 75 at the end of the blade portion 74 in the direction of the rotation axis, and is in contact with an end surface 75c of the regulating portion 75. Furthermore, the end seal member 25 is arranged between the blade portion 74 and the developing roller 6 in the direction intersecting the direction of the rotation axis. The blade portion 74 is welded to the support plate 73 in an area excluding an area outside the end surface 75c of the regulating portion 75 in the direction of the rotation axis.

[0064] Furthermore, the present invention is not limited to the present embodiment, but can be used in various forms as exemplified below.

[0065] So far, an example has been described in which the fixing portions W, which are weld marks between the support plate 73 and the blade portion 74, are formed continuously along the first direction. However, as shown in Figures 10(a) to 10(d), the fixing portions W between the support plate 73 and the blade portion 74 may be formed discontinuously along the first direction, and the shape of each fixing portion W is also arbitrary. Alternatively, the shape of the fixing portions W may be any of the shapes shown in Figures 10(e) to 10(g).

[0066] In the configuration of this embodiment, welding is used as a means for forming the fixing portions W that fix the support plate 73 and the blade portions 74. Any specific welding means may be used, but for example, welding means such as fiber laser welding or YAG laser welding may be used. Fixation by welding is characterized by high fixing strength and a small area required for fixing. If the area of ​​the fixing portions W were large, there is a concern that deformation at both ends of the blade portions 74 in the first direction would be inhibited by the fixing portions W and reduced.

[0067] In this way, welding is preferably used as a means for forming the fixing portion W, which can effectively deform the blade portion 74 and improve the adhesion between the end seal member 25 and the restricting portion 75. Furthermore, it is desirable that the blade portion 74 be welded to the support plate 73 along the rotation axis direction to form a weld mark, and that the weld mark be configured to be formed continuously like the fixing portion W.

[0068] Furthermore, although the present embodiment has been described as a color image forming apparatus, it may also be applied to a monochrome image forming apparatus.

[0069] The elements described in the above embodiments may be combined in any desired manner. [Explanation of symbols]

[0070] 1. Image forming device 2 Image forming device main body (device main body) 6 Developing material (developing roller) 8 (8Y, 8M, 8C, 8K) Developing unit (developing cartridge) 25 Sealing member (end sealing member) 28 Developing frame 72 Regulatory Blade 73 Support plate 74 Plate-shaped member (blade part) 74a Tip 74b Proximal end 74e Blade end 75 Regulatory Department 75a 1st page 75b Side 2 75c end 75d notch

Claims

1. A developing device for use in an image forming apparatus, comprising: a developing frame that accommodates a developer; a rotatable developing member that carries the developer; a regulating blade that is fixed to the developing frame and regulates the developer carried on the surface of the developing member; and a sealing member that seals to prevent the developer from leaking outside the developing frame; The regulating blade is a support plate extending in a first direction, which is the direction of the rotation axis of the developing member; a plate-like member disposed at one end in a second direction intersecting the first direction so as to face the developing member, and supported at the other end in the direction intersecting the first direction by the support plate; a regulating member that regulates the developer carried on the surface of the developing member, the regulating member being fixed at one end to a surface of the plate-like member that faces the developing member, being in contact with the developing member, and having a regulating portion in which an end portion in the first direction has a recess that is recessed in a direction from the one end toward the other end more than a central portion, and is formed inside the end portion of the plate-like member in the first direction; the recess extends in the first direction and is connected to a first surface of the restriction portion extending in the second direction, the sealing member is fixed to the opposing surface of the plate-like member, is disposed at the end of the plate-like member alongside the regulating portion in the first direction, and is in contact with an end surface of the regulating portion when the developing member is in contact with the regulating portion; a developing member disposed between the plate-like member and the developing member in a third direction that is a direction intersecting the first direction and the second direction; the plate-like member is welded to the support plate along the first direction to form weld marks, and the weld marks are formed intermittently; The welding marks are i) on the other end side in the second direction, ii) In the first direction, the central portion of the regulating member overlaps with an area inside the end surface of the sealing member at the end and outside the first surface.

2. 2. The developing device according to claim 1, wherein the regulating member is flexible.

3. the seal member contacts an end surface of the regulating portion when the developing member is in contact with the regulating portion to form a contact portion; 2. The developing device according to claim 1, wherein the welding mark overlaps with an area inside the end face of the sealing member on the side that forms the contact portion in the first direction, the end face of the sealing member that does not form the contact portion and faces the first surface, and outside the first surface.

4. 2. The developing device according to claim 1, wherein the developer is yellow.

5. 2. The developing device according to claim 1, wherein the developer is magenta.

6. 2. The developing device according to claim 1, wherein the developer is cyan.

Images