Developing device and image forming apparatus equipped with same

Abstract

To provide a developing device that can prevent outflow of developer.SOLUTION: A developing device comprises a developer container, a developer carrier, a regulation blade, a pair of pressing members, and a blade seal member. The blade seal member has a first laminated material that is arranged inside the pair of pressing members and is laminated on a surface of the regulation blade on the upstream side with respect to a rotation direction, and a second laminated material that is laminated on a surface of the first laminated material on the opposite side of the regulation blade and has a larger rigidity than that of the first laminated material. The developer container has a pair of opposing surfaces opposite to each other in a rotation axis direction. The second laminated material has positioning projections that project in the rotation axis direction from the first laminated material to contact the opposing surfaces at positions inside both ends of the first laminated material in the rotation axis direction. With the second laminated material positioned in the rotation axis direction, the first laminated material is brought into pressure contact with the pressing members in the rotation axis direction.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a developing device and an image forming apparatus equipped with the same. [Background technology]

[0002] Image forming devices that use electrophotography, such as copiers, printers, facsimiles, and combination machines thereof, are equipped with a developing device for developing an electrostatic latent image formed on the outer surface of an image carrier, i.e., for forming a toner image (developer image) that manifests the electrostatic latent image.

[0003] The developing device includes a developing container that contains developer including toner, and a developer carrier that is arranged in contact with or close to an image carrier and carries the developer. The developing container has a container opening that opens downstream of the developing device in the direction of movement of the developing device. The developer carrier is arranged so as to overlap the container opening. A portion of the developer carrier is exposed to the outside of the developing device through this container opening. The developer carrier is capable of carrying toner in the developing container on its outer circumferential surface. The exposed portion of the developer carrier from the container opening faces the image carrier, forming a development area that supplies toner in the developer container to the image carrier.

[0004] As such a developing device, Patent Document 1 discloses one in which a regulating blade is arranged upstream of the development area in the direction of rotation of the developer carrier. The regulating blade protrudes toward the outer peripheral surface of the developer along the entire area along the direction of the rotation axis of the developer carrier. The tip of the regulating blade is in contact with or close to the outer peripheral surface of the developer carrier. The regulating blade regulates the layer thickness of the developer carried by the developer carrier.

[0005] A seal member (blade seal member) is disposed between the regulating blade and the developing container. This seal member is in contact with the regulating blade over the entire longitudinal direction (rotational axis direction) of the regulating blade. The seal member seals the gap between the regulating blade and the developing container, preventing the developer in the developing container from leaking out.

[0006] A pair of pressing members is provided in the gap between the developer container and both ends of the developer carrier in the rotational axis direction. The pressing members protrude from the inner surface of the developer container toward the outer peripheral surface of the developer carrier, and contact and press the outer peripheral surface of both ends of the developer carrier. The contact and pressure between the pressing members and the outer peripheral surface of the developer carrier closes the gap between the developer container and the developer carrier, preventing the developer from leaking out. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-164736 Summary of the Invention [Problem to be solved by the invention]

[0008] The developing device described above is configured so that both ends of the seal member contact the inner surface of the developer container to prevent gaps from forming between the both ends of the seal member in the direction of the rotation axis and the developer container. However, if the seal member is positioned to one side in the direction of the rotation axis, the contact pressure between the other end of the seal member and the developer container will be weak. This could result in a gap between the other end and the developer container due to the pressure of the developer inside the developer container, potentially causing the developer to leak out. However, because the seal member is made of a material such as a sponge with relatively low rigidity, it has been difficult to position it with the appropriate contact pressure.

[0009] SUMMARY OF THE INVENTION An object of the present invention is to provide a developing device that can prevent developer from leaking out. [Means for solving the problem]

[0010] In order to achieve the above object, the first configuration of the present invention is a developing device comprising a developing container, a developer carrier, a regulating blade, and a pair of pressing members. The developing container has an opening and contains developer including toner inside. The developer carrier is rotatably supported in the developing container, and has a developing area where a portion of the outer circumferential surface carrying the developer is exposed from the opening and faces the image carrier, and supplies toner to the image carrier in the developing area. The regulating blade is disposed upstream of the developing area in the direction of rotation of the developer carrier, and regulates the layer thickness of the developer carried by the developer carrier. The pair of pressing members contact both ends of the developer carrier in the rotational axis direction and close the gap between both ends of the developer carrier and the developing container. The developing device is provided with a blade seal member. The blade seal member is disposed inside the pair of pressing members in the rotational axis direction and includes a first laminated material laminated on the surface of the regulating blade upstream in the rotational direction of the developer carrier, and a second laminated material having greater rigidity than the first laminated material laminated on the surface of the first laminated material opposite the regulating blade. The developing container has a pair of opposing surfaces facing each other in the rotational axis direction. The second laminated material has positioning protrusions that protrude from the first laminated material in the rotational axis direction at a position inside both ends of the first laminated material in the rotational axis direction and contact the pair of opposing surfaces, thereby being positioned in the rotational axis direction. The first laminated material is pressed against the pressing members in the rotational axis direction with the second laminated material positioned in the rotational axis direction. [Effects of the Invention]

[0011] According to the first configuration of the present invention, the second laminate is laminated on the first laminate, and thus the blade seal member is positioned by positioning the second laminate. The second laminate has greater rigidity than the first laminate, making it easier to position the blade seal member through contact between the positioning protrusion and the opposing surface. Furthermore, with the blade seal member positioned, the first laminate is pressed against the pressing member, and the pressing member closes the gap between the developer container and the blade seal member in the rotational axis direction, thereby blocking the developer outflow path. This provides a developing device that can prevent developer from leaking out. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a cross-sectional side view showing a schematic configuration of an image forming apparatus 1 according to the present invention. [Figure 2] FIG. 3 is a perspective view showing the entire developing device 33. [Figure 3] 1 is an enlarged cross-sectional view of the photosensitive drum 31 and the peripheral portion of the developing device 33. [Figure 4] 2 is a plan view showing the developing device 33 in a state where the developing roller 37 (see FIG. 2), the regulating blade 64 (see FIG. 2), and the bush cover 63 (see FIG. 2) are removed from the developing container 36. [Figure 5] 5 is a side cross-sectional view of the developing device 33 taken along the line AA shown in FIG. [Figure 6] 1 is a perspective view showing a blade seal member 67. [Figure 7] 5 is a partially enlarged view of the periphery of the end of the blade seal member 67 of the developing device 33 (the area surrounded by the two-dot chain circle B in FIG. 4). DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a side cross-sectional view showing a schematic configuration of an image forming apparatus 1 of the present invention. In Fig. 1, the right side of the figure is the front side of the image forming apparatus 1, and the left side of the figure is the rear side of the image forming apparatus 1. In Fig. 1, the upper side of the figure is the upper side of the image forming apparatus 1, and the lower side of the figure is the lower side of the image forming apparatus 1.

[0014] As shown in FIG. 1, image forming apparatus 1 (here, a monochrome printer) includes a main housing 10 (device main body) having a substantially rectangular parallelepiped casing structure, and a paper feed unit 20, an image forming unit 30, a developing device 33, and a fixing unit 40 housed within main housing 10. A front cover 11 is provided on the front side of main housing 10, and a rear cover 12 is provided on the rear side. A main opening 15 is provided above main housing 10, and an upper cover 16 is provided on the top surface of main housing 10 so that main opening 15 can be opened and closed. By opening upper cover 16, the interior of main housing 10 can be accessed through main opening 15.

[0015] A paper discharge section 13 onto which sheets (recording media) after image formation are discharged is provided on the top surface of the upper cover 16. In the following description, the term "sheet" refers to copy paper, coated paper, overhead projector sheets, cardboard, postcards, tracing paper, and other sheet materials that undergo image formation processing.

[0016] When the upper cover 16 is opened, the developing device 33 can be taken in and out through the main body opening 15. When the rear cover 12 is opened, the image forming unit 30 and the fixing unit 40 units (except the developing device 33) can be taken in and out from the rear side of the main body housing 10.

[0017] The paper feed unit 20 includes a paper feed cassette 21 that stores sheets on which image formation processing is performed. A portion of the paper feed cassette 21 protrudes further forward from the front surface of the main body housing 10. The upper surface of the portion of the paper feed cassette 21 that is stored within the main body housing 10 is covered by a paper feed cassette top plate 21U. The paper feed cassette 21 is equipped with a paper storage space that stores a stack of sheets, a lift plate that lifts up the stack of sheets for feeding, and the like. A paper feed unit 21A is provided above the rear end of the paper feed cassette 21. A paper feed roller 21B is arranged in this paper feed unit 21A to feed the topmost sheet of the stack of sheets in the paper feed cassette 21 one by one.

[0018] Image forming unit 30 performs an image forming operation to form a toner image (developer image) on a sheet fed from paper feed unit 20. Image forming unit 30 includes a photosensitive drum 31, and a charging unit 32, an exposure unit 35, a developing device 33, and a transfer roller 34, which are arranged around photosensitive drum 31. The developer used for image formation is a non-magnetic one-component developer consisting only of toner.

[0019] The photosensitive drum 31 (image carrier) has a rotation shaft and an outer circumferential surface that rotates around the rotation shaft. The outer circumferential surface of the photosensitive drum 31 is made of, for example, a known organic photoconductor (OPC), and a photosensitive layer composed of a charge generation layer, a charge transport layer, etc. is formed on the outer circumferential surface. The photosensitive layer is uniformly charged by a charging unit 32 (described later), and then irradiated with light by an exposure unit 35 to form an electrostatic latent image by attenuating the charge. The electrostatic latent image is then visualized by a developing device 33, and a toner image is formed on the photosensitive layer.

[0020] The charging unit 32 (charging device) is disposed at a predetermined distance from the outer circumferential surface of the photosensitive drum 31 and uniformly charges the outer circumferential surface of the photosensitive drum 31 without contacting the photosensitive drum 31. Specifically, the charging unit 32 has a charge wire 321 and a grid electrode 322 (see FIG. 3 for both). The charge wire 321 is a linear electrode extending in the direction of the rotational axis of the photosensitive drum 31 and generates a corona discharge between the charge wire 321 and the photosensitive drum 31. The grid electrode 322 is a lattice-shaped electrode extending in the direction of the rotational axis of the photosensitive drum 31 and is disposed between the charge wire 321 and the photosensitive drum 31. The charging unit 32 generates a corona discharge by passing a predetermined current through the charge wire 321 and uniformly charges the outer circumferential surface of the photosensitive drum 31 facing the grid electrode 322 to a predetermined surface potential by applying a predetermined voltage to the grid electrode 322.

[0021] The exposure unit 35 (exposure device) has a laser light source and optical devices such as mirrors and lenses, and irradiates the outer peripheral surface of the photosensitive drum 31 with light modulated based on image data provided from an external device such as a personal computer. In this way, the exposure unit 35 forms an electrostatic latent image on the outer peripheral surface of the photosensitive drum 31 that corresponds to the image based on the image data.

[0022] The transfer roller 34 has a rotation axis parallel to the width direction of the sheet and an outer circumferential surface facing the outer circumferential surface of the photosensitive drum 31, and is supported by the main housing 10 so as to be rotatable about the rotation axis. The transfer roller 34 transfers the toner image carried on the outer circumferential surface of the photosensitive drum 31 onto the sheet that passes through the nip portion between the transfer roller 34 and the outer circumferential surface of the photosensitive drum 31. During transfer, a transfer voltage of opposite polarity to that of the toner is applied to the transfer roller 34.

[0023] The fixing unit 40 is located downstream of the transfer roller 34 in the sheet conveyance direction, and fixes the toner image transferred to the sheet onto the sheet. The fixing unit 40 has a fixing roller 41 and a pressure roller 42. The fixing roller 41 has an internal heating source and heats the toner transferred to the sheet to a predetermined temperature. The pressure roller 42 is pressed against the fixing roller 41, forming a fixing nip between the fixing roller 41 and the pressure roller 42. When the sheet onto which the toner image has been transferred is passed through the fixing nip, the toner image is fixed onto the sheet by the heating by the fixing roller 41 and the pressure by the pressure roller 42.

[0024] A main transport path 22F and a reverse transport path 22B for transporting sheets are provided within the main body housing 10. The main transport path 22F extends from the paper feed unit 21A of the paper feed unit 20, via the image forming unit 30 and the fixing unit 40, to the paper discharge port 14 provided opposite the paper discharge unit 13 on the top surface of the main body housing 10. The reverse transport path 22B is a transport path for returning a sheet that has been printed on one side to the upstream side of the image forming unit 30 on the main transport path 22F when double-sided printing is performed on the sheet.

[0025] The main transport path 22F extends from below to above the transfer nip formed by the photosensitive drum 31 and the transfer roller 34. A pair of registration rollers 23 is disposed on the main transport path 22F upstream of the transfer nip. The sheet is temporarily stopped by the pair of registration rollers 23, where skew correction is performed, and then the sheet is sent to the transfer nip at a predetermined timing for image transfer. A plurality of transport rollers for transporting the sheet are disposed at appropriate positions on the main transport path 22F and the reverse transport path 22B. A pair of paper discharge rollers 24 is disposed near the paper discharge outlet 14.

[0026] The reverse conveying path 22B is formed between the outer surface of the reversing unit 25 and the inner surface of the rear cover 12 of the main housing 10. The transfer roller 34 and one of the pair of registration rollers 23 are mounted on the inner surface of the reversing unit 25. The rear cover 12 and the reversing unit 25 are each rotatable about a fulcrum 121 provided at their lower ends. If a jam (paper jam) occurs in the reverse conveying path 22B, the rear cover 12 is opened. If a jam occurs in the main conveying path 22F, or if the photosensitive drum 31 unit or the developing device 33 is removed to the outside, the reversing unit 25 is also opened in addition to the rear cover 12.

[0027] As shown in Fig. 1, guide rails 18 are formed on a pair of side surfaces 17 that face each other in the width direction of the sheet (the plane of the paper in Fig. 1) inside the main body housing 10. The guide rails 18 have a rail structure that is recessed in the width direction of the sheet. The guide rails 18 extend downward from the main body opening 15 to a mounting position P1 of the developing device 33 relative to the main body housing 10.

[0028] Fig. 2 is a perspective view showing the entire developing device 33. Fig. 3 is an enlarged cross-sectional view showing the photosensitive drum 31 and the peripheral portion of the developing device 33. Fig. 4 is a plan view showing the developing device 33 in a state where the developing roller 37 (see Fig. 2), the regulating blade 64 (see Fig. 2), and the bush cover 63 (see Fig. 2) have been removed from the developing container 36.

[0029] As shown in FIGS. 2, 3, and 4, the developing device 33 includes a developer container 36, a developing roller 37 (developer carrier), a supply roller 38, an agitating paddle 333, and a guide portion 69.

[0030] The developing container 36 has a stirring chamber 335 that contains the developer in a stirred state, a container opening 60 (opening) located rearward of the stirring chamber 335 in the front-to-rear direction, and bush covers 63 that are removably attached to both ends of the developing container 36 in the sheet width direction, and contains a non-magnetic one-component developer consisting only of toner inside, as well as a developing roller 37, a supply roller 38, etc.

[0031] The container opening 60 is a rectangular through-hole that opens to the rear side (the side closer to the photosensitive drum 31) of the developing container 36. The container opening 60 is formed to be elongated in the width direction (axial direction) of the developing device 33.

[0032] The developing roller 37 is provided inside the container opening 60 so as to overlap with the container opening 60. A portion of the outer circumferential surface of the developing roller 37 is exposed to the outside of the developing container 36 through the container opening 60. The developing roller 37 has a rotation shaft 39 extending along the width direction of the developing device 33 (width direction of the sheet). The rotation shaft 39 is rotatably supported by the developing container 36. In other words, the developing roller 37 is supported by the developing container 36 via the rotation shaft 39 so as to be rotatable clockwise around the rotation shaft 39 (see FIG. 3). Hereinafter, the direction along the rotation shaft 39 will be referred to as the "axial direction."

[0033] The developing roller 37 is capable of carrying toner on its outer circumferential surface. When the developing device 33 is in the mounting position P1, the portion of the developing roller 37 exposed from the container opening 60 is in contact with or closely faces the outer circumferential surface of the photosensitive drum 31. In this state, the developing roller 37 is capable of supplying non-magnetic single-component toner (developer) to the photosensitive drum 31.

[0034] Supply roller 38 is provided between developing roller 37 and stirring paddle 333, and supplies non-magnetic single-component toner (developer) to the outer peripheral surface of developing roller 37. Stirring paddle 333 is provided inside stirring chamber 335, and stirs the developer inside stirring chamber 335.

[0035] The bush covers 63 are detachably provided at both axial ends of the developing container 36, and form side walls of the developing container 36. The bush covers 63 are formed with a plurality of through holes that penetrate in the axial direction, and the rotation shafts of the developing roller 37 and the supply roller 38 are inserted into these through holes, thereby rotatably supporting the developing roller 37 and the supply roller 38.

[0036] The guide portion 69 is a cylindrical protrusion protruding from the bush cover 63. The guide portion 69 is engageable with the guide rail 18. The developing device 33 is movable along the guide rail 18 between the main body opening 15 and the mounting position P1 by engaging the guide portion 69 with the guide rail 18.

[0037] The developing device 33 mounted in the main body housing 10 at the mounting position P1 supplies toner to the outer peripheral surface of the photosensitive drum 31. This develops the electrostatic latent image formed on the outer peripheral surface of the photosensitive drum 31 (forming a toner image (visible image) that manifests the electrostatic latent image).

[0038] As shown in Figures 2 and 4, around the container opening 60, there are provided pressing members 43 provided at both axial ends of the developing roller 37, a flat portion 62 located rearward of the container opening 60 (closer to the photosensitive drum 31), a front seal member 65 provided on the flat portion 62, a regulating blade 64 fixed to the rear end of the developing container 36, and a blade seal member 67 laminated on the back side of the regulating blade 64.

[0039] Fig. 5 is a side cross-sectional view of the developing device 33 taken along the AA cross-sectional line shown in Fig. 4. Fig. 6 is a perspective view showing the blade seal member 67. Fig. 7 is a partial enlarged view of the periphery of the end of the blade seal member 67 of the developing device 33 (the area surrounded by the two-dot chain circle B in Fig. 4). Note that the blade seal member 67 shown in Fig. 6 is shown in a state where the blade seal member 67 shown in Fig. 4 is inverted in the front-to-back direction, and the left-to-right directions are reversed between Figs. 4 and 6.

[0040] The pressing members 43 are disposed on both axial ends of the container opening 60 (see FIG. 2). As shown in FIG. 5, the pressing members 43 have pressing surfaces 44 that curve along the outer peripheral surface of the developing roller 37 and are recessed forward (toward the stirring chamber 335). The pressing surfaces 44 face the outer peripheral surfaces of both end portions 66 of the developing roller 37 in the radial direction of the developing roller 37. The thickness of the pressing members 43 is greater than the gap between the outer peripheral surface of the developing roller 37 and the inner surface of the developing container 36. As a result, when the developing roller 37 is attached to the developing container 36, the pressing surfaces 44 come into contact with the outer peripheral surface of the developing roller 37 and press the developing roller 37 in the radial direction. The pressing surfaces 44 come into contact with and press the both end portions 66, thereby closing the gap between the both end portions 66 and the developing container 36 and preventing the developer from leaking out of the developing container 36.

[0041] The pressing member 43 has a multi-layer structure (here, a two-layer structure) in which a plurality of sheets are stacked in the radial direction of the developing roller 37. Of these multi-layer sheets, at least the sheet closest to the developing roller 37 in the radial direction is a polytetrafluoroethylene (also known as Teflon (registered trademark)) sheet. The pressing surface 44 is formed on the surface of this sheet. The other sheets of the multi-layer sheet are made of urethane foam such as sponge.

[0042] 2 and 3, the flat portion 62 located around the container opening 60 is a flat surface that connects to a portion of the inner surface of the developer container 36 that is located below the developing roller 37. The flat portion 62 extends rearward (toward the photosensitive drum 31) from the container opening 60. When the developing device 33 is in the mounting position P1, the flat portion 62 is approximately horizontal.

[0043] The front seal member 65 is a rectangular sheet made of a PET film or the like. The front seal member 65 is laminated on the flat portion 62 and adhered to the developing container 36 with an adhesive or the like. The front seal member 65 is formed to be elongated in the axial direction. The front seal member 65 extends between both end portions 66 of the developing roller 37 along the axial direction.

[0044] Of both edge portions of the front seal member 65 in the front-rear direction (the direction perpendicular to the sheet width direction), the edge portion closest to the developing roller 37 (supply roller 38) is in axial contact with the entire developer-carrying area of ​​the outer peripheral surface of the developing roller 37. By contacting the outer peripheral surface of the developing roller 37, the front seal member 65 closes the gap between the developing container 36 and the developing roller 37, thereby preventing the developer in the developing container 36 from leaking out.

[0045] The front seal member 65 has a first shielding portion 19 that rises in the surface direction of the front seal member 65 from the edge farthest from the developing roller 37 (supply roller 38) of both end edges in the front-rear direction (the direction perpendicular to the sheet width direction). The first shielding portion 19 protrudes upward over the entire axial area of ​​the edge of the front seal member 65. The first shielding portion 19 has a rectangular shape made of sponge or the like, and is adhered to the surface of the front seal member 65 with an adhesive or the like. The first shielding portion 19 prevents the small amount of developer that leaks out from the gap between the developing roller 37 and the developing container 36 from falling outside the developing device 33.

[0046] Plate-shaped second shielding portions 53 that protrude upward are provided on the outside of both axial end portions of the first shielding portion 19. The second shielding portions 53 are located so as to overlap with the pressing member 43 in the axial direction. The second shielding portions 53 are formed integrally with the bush cover 63. When the bush cover 63 is attached to the developing container 36, the second shielding portions 53 extend from the bush cover 63 along the axial direction so as to approach the first shielding portion 19.

[0047] 2 and 3, the regulating blade 64 is a rectangular plate-like body that is elongated in the direction of the rotation axis. The regulating blade 64 is provided above the edge of the container opening 60 and protrudes toward the developing roller 37. The tip of the regulating blade 64 in the protruding direction is disposed in contact with or close to the outer circumferential surface of the developing roller 37. As the developing roller 37 rotates, the toner supplied onto the developing roller 37 enters between the regulating blade 64 and the developing roller 37, and while being further frictionally charged, is carried on the developing roller 37 as a thin layer of a certain thickness.

[0048] 3 and 5, a blade seal member 67 is provided between the regulating blade 64 and the developing container 36 in the front-rear direction (the direction perpendicular to the axial direction). The blade seal member 67 is made up of a multi-layer sheet including a first laminated material 70 and a second laminated material 71 that are laminated in the front-rear direction.

[0049] The first laminated material 70 is laminated on the surface of the regulating blade 64 farther from the photosensitive drum 31 in the direction perpendicular to the axial direction (front-rear direction) (the surface located upstream of the regulating blade 64 in the direction of rotation of the developing roller 37), and is adhered with an adhesive or the like. The first laminated material 70 is made of sponge such as Poron. The first laminated material 70 is formed to be elongated in the axial direction.

[0050] 4, the first laminated material 70 is disposed between a pair of pressing members 43 in the axial direction. Both axial end portions of the first laminated material 70 are in pressure contact with (contact with and press against) the pressing members 43. Of the axial side edges of the first laminated material 70, the lower side edge overlaps the upper edge portion of the container opening 60.

[0051] 4 and 6, the first laminated material 70 is composed of a first seal member 72 and a second seal member 73, which are aligned in the axial direction. A connecting portion 74 is formed at the opposing portion of the first seal member 72 and the second seal member 73.

[0052] The first seal member 72 has a first protrusion 75 and a first recess 76 formed at an end located toward the center of the container opening 60 in the axial direction. The first protrusion 75 protrudes in the axial direction from the end of the first seal member 72. The first recess 76 is recessed from the tip of the first protrusion 75 in the protruding direction in the direction opposite to the protruding direction. The first protrusion 75 and the first recess 76 are adjacent to each other in a direction perpendicular to the axial direction.

[0053] The second seal member 73 has a second protruding portion 77 and a second recessed portion 78 formed at an end portion located toward the center of the container opening 60 in the axial direction. The second protruding portion 77 protrudes in the axial direction from the end portion of the second seal member 73. The second recessed portion 78 is recessed from the tip of the second protruding portion 77 in the protruding direction in the direction opposite to the protruding direction. The second protruding portion 77 and the second recessed portion 78 are adjacent to each other in a direction perpendicular to the axial direction.

[0054] The second protruding portion 77 overlaps with the first recessed portion 76 in a direction (up-down direction) perpendicular to the axial direction. The length from the bottom of the second recessed portion 78 to the tip of the second protruding portion 77 is equal to or slightly smaller than the length from the bottom of the first recessed portion 76 to the tip of the first protruding portion 75. The first protruding portion 75 is inserted into the second recessed portion 78, and the second protruding portion 77 is inserted into the first recessed portion 76.

[0055] The connecting portion 74 is composed of a first protrusion 75, a first recess 76, a second protrusion 77, and a second recess 78, and joins the first sealing member 72 and the second sealing member 73 in the axial direction by adhesive applied to seal the gap between the first protrusion 75 and the second recess 78, and the gap between the first recess 76 and the second protrusion 77.

[0056] The second laminate 71 is an axially elongated sheet material made of polyethylene terephthalate (PET). The second laminate 71 has greater rigidity than the first laminate 70. As shown in FIGS. 5 and 6, the second laminate 71 is laminated on the surface of the first laminate 70 opposite the surface that comes into contact with the regulating blade 64 (the surface farther from the developing roller 37 in the front-to-rear direction), and is adhered thereto with an adhesive or the like. One second laminate 71 is laminated on each of the first seal member 72 and the second seal member 73.

[0057] The axial length of the second laminated material 71 is shorter than the axial length of the blade seal member 67. Both end portions of the second laminated material 71 are located axially more inward than both end portions of the blade seal member 67. In the regions extending from both axial end portions of the blade seal member 67 to both end portions of the second laminated material 71, cushion portions 68 are formed in which the first laminated material 70 protrudes from the second laminated material 71.

[0058] The second laminated material 71 is provided with seal-side positioning protrusions 79 (positioning protrusions) at positions axially symmetrical and further inward than both end portions of the second laminated material 71. The seal-side positioning protrusions 79 protrude outward in the axial and vertical directions beyond the edges of the blade seal member 67 (see FIG. 7).

[0059] 4 and 7, container-side positioning protrusions 80 are formed on both axial ends of the container opening 60, protruding downward from a portion of the inside of the developing container 36. An opposing surface 81 is formed on the surface of each container-side positioning protrusion 80 that is closer to the center of the container opening 60 in the axial direction. The opposing surfaces 81 of the container-side positioning protrusions 80 face each other in the axial direction, with a portion of the blade seal member 67 sandwiched therebetween.

[0060] The seal-side positioning protrusions 79 are located inside each container-side positioning protrusion 80 in the axial direction. The seal-side positioning protrusions 79 and the container-side positioning protrusions 80 are positioned so as to overlap in the vertical direction. The seal-side positioning protrusions 79 face the container-side positioning protrusions 80 in the axial direction. The seal-side positioning protrusions 79 come into contact with the container-side positioning protrusions 80, thereby positioning the second laminated material 71 in the axial direction.

[0061] As described above, the second laminate 71 is positioned by contact between the seal-side positioning protrusion 79 and the opposing surface 81. Because the second laminate 71 has greater rigidity than the first laminate 70, contact between the seal-side positioning protrusion 79 and the opposing surface 81 facilitates positioning of the blade seal member 67. Here, the second laminate 71 is laminated and bonded to the first laminate 70, and positioning the second laminate 71 positions the first laminate 70, i.e., the blade seal member 67. In this state, the first laminate 70 is pressed against the pressing member 43, and the gap between the developer container 36 and the blade seal member 67 in the rotational axis direction is blocked via the pressing member 43, thereby blocking the developer outflow path. Therefore, a developing device 33 capable of suppressing developer outflow can be provided.

[0062] As described above, both ends of the second laminated material 71 are located axially inward of both ends of the first laminated material 70, and cushion portions 68 are formed in the portions of the first laminated material 70 extending from both ends of the second laminated material 71 to both ends of the first laminated material 70. Therefore, when the blade seal member 67 is positioned and both ends of the first laminated material 70 contact the pressing member 43, the cushion portions 68 are compressed. This increases the compression rate of the portions of the first laminated material 70 that contact the pressing member 43 (cushion portions 68), thereby improving the sealing performance between the first laminated material 70 and the pressing member 43. This more effectively prevents the developer from leaking out.

[0063] As described above, the first laminated material 70 connects the separately formed first seal member 72 and second seal member 73 via the connecting portion 74. The second laminated material 71 is laminated on each of the first seal member 72 and the second seal member 73. Therefore, when the blade seal member 67 is disposed between the pair of pressing members 43 in the axial direction, it can be disposed with a gap (a gap) between each pressing member 43 and the first seal member 72 and the second seal member 73. In this state, the first seal member 72 and the second seal member 73 can be bonded with an adhesive at a distance that generates a predetermined contact pressure between the blade seal member 67 and the pressing member 43. This improves assembly efficiency and reduces the manufacturing cost of the developing device 33.

[0064] Furthermore, a first shielding portion 19 is provided that protrudes upward along the entire longitudinal edge of the front seal member 65. Therefore, even if waste toner has accumulated around the container opening 60, when the developing device 33 is facing downward when attached to the main body housing 10, the waste toner around the container opening 60 is blocked by the first shielding portion 19. This makes it possible to prevent the waste toner from falling into the main body housing 10.

[0065] Therefore, it is possible to provide a developing device 33 that can prevent developer from leaking out from the gap between the developing roller 37 and the developing container 36, while also preventing developer from falling into the inside of the main housing 10 from around the container opening 60 of the developing device 33.

[0066] As described above, the second shielding portion 53 is located at a position overlapping the pressing member 43 in the axial direction. Therefore, even if a small amount of developer leaks out from the gap between the pressing member 43 and the developing roller 37, the second shielding portion 53 prevents the developer from leaking out of the developing container 36. As described above, the second shielding portion 53 is formed integrally with the bush cover 63. Therefore, when the bush cover 63 is attached, the second shielding portion 53 is also positioned at a predetermined position. This reduces the number of assembly steps and suppresses manufacturing costs.

[0067] Furthermore, the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention. For example, in the above-described embodiment, a monochrome printer was described as an example of the image forming apparatus 1, but the present invention can also be applied to, for example, a tandem or rotary color printer. The present invention can also be applied to image forming apparatuses such as copiers, facsimiles, and multifunction machines equipped with these functions.

[0068] In the above embodiment, the first shielding portion 19 is formed from a sponge, but this is not limiting and the first shielding portion 19 may be formed from another material. Alternatively, the first shielding portion 19 may be formed integrally with the front seal member 65 and bent upward from the edge of the front seal member 65. In this case, the number of parts of the front seal member 65 can be reduced, thereby reducing manufacturing costs.

[0069] Furthermore, in the above embodiment, the developer is a non-magnetic one-component developer made up of only toner, but it is also possible to adopt a two-component developer using toner and carrier. [Industrial Applicability]

[0070] The present invention can be applied to an image forming apparatus equipped with a developing device that performs development using a developer containing toner, and by using the present invention, it is possible to provide an image forming apparatus that can prevent the developer from leaking out of the developing device. [Explanation of symbols]

[0071] 1. Image forming device 10 Main body housing (device main body) 19 1st shielding part 31 Photosensitive drum (image carrier) 33 Developing device 36 Developer container 37 Developing roller (developer carrier) 39 Rotational Axis 43 Pressing member 60 Container opening (opening 64 Regulatory Blade 66 Both ends of the developing roller 67 Blade seal member 70 First laminate 71 Second laminate 72 first seal member 73 Second seal member 74 Connecting part 75 1st protrusion 76 First recess 77 Second protrusion 78 Second recess 79 Seal side positioning protrusion (positioning protrusion) 81 Opposite surface

Claims

1. a developer container having an opening and accommodating a developer including a toner therein; a developer carrier that is rotatably supported by the developing container, has a development area in which a part of an outer peripheral surface that carries the developer is exposed through the opening and faces an image carrier, and supplies the toner to the image carrier in the development area; a regulating blade disposed upstream of the developing region in a rotation direction of the developer carrier and regulating a layer thickness of the developer carried by the developer carrier; a pair of pressing members that contact both ends of the developer carrier in the rotation axis direction and close a gap between the both ends of the developer carrier and the developing container; In a developing device comprising: a blade seal member including: a first laminate material that is disposed inside the pair of pressing members in the direction of the rotation axis and laminated on a surface of the regulating blade on the upstream side in the direction of the rotation axis of the developer carrier; and a second laminate material that is laminated on a surface of the first laminate material on the opposite side to the regulating blade and has a rigidity greater than that of the first laminate material, the developing container has a pair of opposing surfaces opposed to each other in the direction of the rotation axis, The second laminated material has a positioning protrusion that protrudes from the first laminated material in the rotational axis direction and contacts the pair of opposing surfaces at a position inside both ends of the first laminated material in the rotational axis direction, and is positioned in the rotational axis direction, a developing device according to claim 1, wherein the first laminate is pressed against the pressing member in the direction of the rotation axis with the second laminate being positioned in the direction of the rotation axis.

2. 2. The developing device according to claim 1, wherein both end portions of the second laminate in the direction of the rotation axis are located inside both end portions of the first laminate in the direction of the rotation axis.

3. the first laminated material includes a first seal member and a second seal member aligned in the rotation axis direction, and a connecting portion formed at an opposing portion of the first seal member and the second seal member, 3. The developing device according to claim 1, wherein the connecting portion has a first protruding portion protruding in the rotational axis direction from an end of the first seal member on the second seal member side toward the second seal member in the rotational axis direction, a first recessed portion recessed from the end of the first seal member in a direction opposite to a protruding direction of the first protruding portion, a second protruding portion protruding in the rotational axis direction from an end of the second seal member on the first seal member side in the rotational axis direction and inserted into the first recessed portion, and a second recessed portion recessed from the end of the second seal member in a direction opposite to the protruding direction of the second protruding portion and into which the first protruding portion is inserted, and the first seal member and the second seal member are bonded together by applying an adhesive to at least a portion between the first protruding portion and the second recessed portion and between the first recessed portion and the second protruding portion, and a gap between the first seal member and the second seal member is closed by the adhesive.

4. 4. The developing device according to claim 1, wherein the first laminated material is a sponge.

5. 5. The developing device according to claim 1, wherein the second laminated material is a sheet material made of polyethylene terephthalate.

6. A device body, the image carrier provided inside the apparatus body and having an outer circumferential surface on which an electrostatic latent image is formed; 6. The developing device according to claim 1, which is detachably provided inside the main body of the apparatus and, in a state where the developing device is attached inside the main body of the apparatus, the developer carrier comes into contact with or is close to an outer circumferential surface of the image carrier to develop the electrostatic latent image into a toner image; An image forming apparatus comprising:

Images