Developing device and image forming apparatus equipped with same

Abstract

To provide a developing device that can prevent outflow of developer with a cover member attached thereto.SOLUTION: A developing device comprises a developer container, a developer carrier, and a cover member. The developer container has an opening. The developer carrier is rotatably supported on the developer container and has a developing area in which part of an outer peripheral surface carrying developer is exposed from the opening. The cover member has a front face part that is opposite to the entire area in a rotation axis direction of the developer carrier, an upper face part and a lower face part that are erected toward the developer container from side ends of the front face part extending along the rotation axis direction and opposite to each other across the developer carrier, side face parts that are erected toward the developer container from one edge in the rotation axis direction of the front face part, and reinforcement ribs that are formed at a connection part of the lower face part and the front face part, and the cover member is removably attached to the developer container to cover the developer carrier with at least the front face part and the upper face part. When the cover member is attached to the developer container, gaps are formed between the reinforcement ribs and the developer container.SELECTED DRAWING: Figure 6

Description

[Technical field]

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

[0002] Electrophotographic image forming apparatuses 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 peripheral surface of an image carrier, that is, for forming a toner image (visible image) by visualizing the electrostatic latent image.

[0003] As such a developing device, Patent Document 1 discloses one including a developing container that contains a developer containing a toner, and a developer carrier that is arranged in contact with or in close proximity to an image carrier and carries the developer. The developing container has a container opening that opens on the downstream side of the developing container with respect to the direction of movement inside the image forming device when the developing device is mounted on the image forming device. The developer carrier is arranged so as to overlap with the container opening. A part of the developer carrier is exposed to the outside of the developing device through this container opening. The developer carrier is capable of carrying the toner in the developing container on its outer circumferential surface. The exposed part of the developer carrier from the container opening faces the image carrier, and a development area is formed in which the toner in the developing container is supplied to the image carrier.

[0004] In an image forming apparatus equipped with such a developing device, a main body opening that communicates with the inside and outside of the main body is formed above the main body (main body) of the image forming apparatus. Inside the main body, a guide rail is provided to guide the developing device from the main body opening to the mounting position of the developing device. The developing device moves within the main body of the apparatus along this guide rail from the main body opening to the mounting position.

[0005] Some of such developing devices are provided with a cover member that is detachably attached to the developing container so as to cover the developer carrier in order to protect the developer carrier during transportation or storage of the developing device. The cover member is attached to the developing container at the stage of shipping the developing device, and is removed from the developing container when the developing device is installed in an image forming apparatus.

[0006] In order to reduce weight, such a cover member is generally formed into a shape composed of multiple relatively thin surfaces. For this reason, reinforcing ribs are formed on the inner surface (the side toward the mounting direction to the container opening) to suppress deformation due to impact during transportation, and to suppress thermal shrinkage during molding if the cover member is made of resin. When the cover member is mounted to the container opening, the reinforcing ribs are configured to abut against a predetermined location of the developing container. This makes it possible to mount the cover member to the container opening with the cover member positioned at an appropriate position. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2018-091892 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, because the reinforcing ribs are in contact with the developing container, vibrations and shocks during transportation and storage are transmitted to the developing container via the reinforcing ribs, which may cause the developer in the developing container to leak out. This may cause the developer to leak out to the inside of the cover member, causing the developer to scatter when the cover member is removed, or the developer to leak out from the gap between the cover member and the developer, causing the surrounding area and the user's hands to get dirty.

[0009] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a developing device capable of preventing developer from leaking out with a cover member attached. [Means for solving the problem]

[0010] In order to achieve the above object, the first configuration of the present invention is a developing device including a developing container, a developer carrier, and a cover member. The developing container has an opening and contains a developer including a toner inside. The developer carrier is rotatably supported in the developing container, has a developing area in which a part of the outer peripheral surface carrying the developer is exposed from the opening, and supplies toner to the image carrier in the developing area. The cover member is detachable from the developing container and protects the outer peripheral surface of the developer carrier exposed from the opening. The cover member has a front portion facing the entire area of ​​the developer carrier in the rotation axis direction, an upper surface portion and a lower surface portion that are erected on the developing container side from a side end portion extending along the rotation axis direction of the front portion and that face each other across the developer carrier, a side portion that is erected on the developing container side from one end edge of the front portion in the rotation axis direction, and a reinforcing rib formed at a connecting portion between the lower surface portion and the front portion, and is detachably attached to the developing container so as to cover the developer carrier with at least the front portion and the upper surface portion. When the cover member is attached to the developing container, a gap is formed between the reinforcing rib and the developing container. Effect of the Invention

[0011] According to the first configuration of the present invention, a gap is formed between the reinforcing rib and the developing container when the cover member is attached to the developing container. Therefore, even if vibration or impact is applied to the cover member when the cover member is attached to the developing container, the vibration or impact is unlikely to be transmitted to the developing container.

[0012] Therefore, it is possible to provide a developing device capable of preventing the developer from leaking out even when the cover member is attached. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a side cross-sectional view showing a schematic configuration of an image forming apparatus 1 according to the present invention. [Diagram 2] FIG. 3 is a perspective view showing the entire developing device 33. [Diagram 3]FIG. 2 is an enlarged cross-sectional view of the photoconductor drum 31 and the peripheral portion of the developing device 33 when the developing device 33 is attached to the image forming apparatus 1. [Figure 4] 1 is a perspective view of the cover member 50 as seen from the inside. [Diagram 5] FIG. 2 is a perspective view showing the entire developing device 33 with the cover member 50 attached. [Figure 6] FIG. 2 is a cross-sectional view showing a cross section perpendicular to the axial direction of the developing device 33, the cross section being cut at a position overlapping with the reinforcing rib 56 in the axial direction. [Figure 7] FIG. 2 is a cross-sectional view showing a cross section perpendicular to the axial direction of the developing device 33, the cross section being cut at a position overlapping with the engaging protrusion 57 in the axial direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] 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.

[0015] As shown in Fig. 1, the image forming apparatus 1 (here, a monochrome printer) includes a main housing 10 (apparatus main body) having a substantially rectangular parallelepiped casing structure, and a paper feed section 20, an image forming section 30, a developing device 33, and a fixing section 40 housed within the main housing 10. A front cover 11 is provided on the front side of the main housing 10, and a rear cover 12 is provided on the rear side. A main body opening 15 is provided above the main housing 10, and an upper cover 16 is provided on the top surface of the main housing 10 so that the main body opening 15 can be opened and closed. By opening the upper cover 16, the inside of the main housing 10 can be accessed through the main body opening 15.

[0016] A paper discharge section 13 is provided on the top surface of the upper cover 16, where sheets (recording media) after image formation are discharged. 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.

[0017] The developing device 33 can be taken out and inserted through the main body opening 15 by opening the upper cover 16. The image forming section 30 and the fixing section 40 units (except the developing device 33) can be taken out and inserted through the rear side of the main body housing 10 by opening the rear cover 12.

[0018] The paper feed section 20 includes a paper feed cassette 21 that stores sheets on which an image forming process is performed. A part of the paper feed cassette 21 protrudes further forward from the front surface of the main body housing 10. The upper surface of the part of the paper feed cassette 21 that is stored in the main body housing 10 is covered by a paper feed cassette top plate 21U. The paper feed cassette 21 is provided 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 section 21A is provided at the upper part of the rear end side of the paper feed cassette 21. A paper feed roller 21B is arranged in the paper feed section 21A to feed the topmost sheet of the stack of sheets in the paper feed cassette 21 one by one.

[0019] Image forming unit 30 performs an image forming operation to form a toner image (developer image) on a sheet sent out from paper feed unit 20. Image forming unit 30 includes a photoconductor drum 31, and a charging unit 32, an exposure unit 35, a developing device 33, and a transfer roller 34, which are arranged around the photoconductor drum 31. The developer used for image formation is a non-magnetic one-component developer consisting only of toner.

[0020] The photoconductor drum 31 (image carrier) has a rotating shaft and an outer peripheral surface that rotates around the rotating shaft. The outer peripheral surface of the photoconductor drum 31 is made of, for example, a known organic (OPC) photoconductor, and a photosensitive layer made of a charge generation layer, a charge transport layer, etc. is formed on the outer peripheral 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 in which the charge is attenuated, and a toner image in which the electrostatic latent image is visualized by a developing device 33 is carried on the photoconductor drum 31.

[0021] The charging section 32 (charging device) is disposed at a predetermined interval from the outer peripheral surface of the photosensitive drum 31, and uniformly charges the outer peripheral surface of the photosensitive drum 31 in a non-contact state. Specifically, the charging section 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 rotation 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 rotation axis of the photosensitive drum 31, and is disposed between the charge wire 321 and the photosensitive drum 31. The charging section 32 generates a corona discharge by passing a current of a predetermined current value through the charge wire 321, and applies a predetermined voltage to the grid electrode 322, thereby uniformly charging the outer peripheral surface of the photosensitive drum 31 facing the grid electrode 322 to a predetermined surface potential.

[0022] Exposure section 35 (exposure device) has a laser light source and optical devices such as mirrors and lenses, and irradiates the outer peripheral surface of photoconductor drum 31 with light modulated based on image data provided from an external device such as a personal computer. In this way, exposure section 35 forms an electrostatic latent image on the outer peripheral surface of photoconductor drum 31 that corresponds to an image based on the image data.

[0023] 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 photoreceptor 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 photoreceptor drum 31 to the sheet passing through a nip portion between the transfer roller 34 and the outer circumferential surface of the photoreceptor drum 31. During transfer, a transfer voltage of opposite polarity to that of the toner is applied to the transfer roller 34.

[0024] The fixing unit 40 is located downstream of the transfer roller 34 in the sheet conveying 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.

[0025] A main transport path 22F and a reverse transport path 22B for transporting a sheet are provided inside the main housing 10. The main transport path 22F extends from the paper feed section 21A of the paper feed section 20, via the image forming section 30 and the fixing section 40, to the paper discharge port 14 provided opposite the paper discharge section 13 on the upper surface of the main 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 section 30 on the main transport path 22F when double-sided printing is performed on the sheet.

[0026] The main transport path 22F extends from below to above the transfer nip formed by the photoconductor drum 31 and the transfer roller 34. A pair of registration rollers 23 is disposed upstream of the transfer nip on the main transport path 22F. The sheet is temporarily stopped by the pair of registration rollers 23, and after skew correction, 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 port 14.

[0027] 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 the lower end thereof. When a jam (paper jam) occurs in the reverse conveying path 22B, the rear cover 12 is opened. When a jam occurs in the main conveying path 22F, or when the unit of the photosensitive drum 31 or the developing device 33 is taken out to the outside, the reversing unit 25 is also opened in addition to the rear cover 12.

[0028] As shown in Fig. 1, guide rails 18 are formed on a pair of side surfaces 17 facing each other in the sheet width direction (the paper surface direction of Fig. 1) inside the main body housing 10. The guide rails 18 have a rail structure recessed in the sheet width direction. 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.

[0029] 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 in a state where it is mounted in the image forming apparatus 1.

[0030] As shown in FIGS. 2 and 3, the developing device 33 includes a developing container 36, a developing roller 37 (developer carrier), a supply roller 38, an agitating paddle 333, a guide portion 69, and a cover member 50.

[0031] The developing container 36 has a stirring chamber 335 that contains the developer in a stirred state, and a container opening 60 (opening) located rearward of the stirring chamber 335 in the front-rear direction, and contains a non-magnetic one-component developer consisting only of toner therein, as well as the developing roller 37, the supply roller 38, etc. Side frames 63 are attached to both ends of the developing container 36 in the width direction of the developing device 33 (the axial direction described later).

[0032] The container opening 60 is a rectangular through-hole that opens to the rear side (the side closer to the photoconductor drum 31) of the developing container 36. The container opening 60 is formed elongated in the width direction of the developing device 33.

[0033] The developing roller 37 is provided inside the container opening 60 so as to overlap with the container opening 60. A part of the outer circumferential surface of the developing roller 37 is exposed to the outside of the developing container 36 from the container opening 60. The developing roller 37 has a rotation shaft 39 extending along the width direction of the developing device 33. The rotation shaft 39 is supported by the developing container 36 so as to be rotatable. 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 in the figure around the rotation shaft 39 (see FIG. 3). Hereinafter, the direction along the rotation shaft 39 will be referred to as the "axial direction."

[0034] The developing roller 37 can carry 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 can supply non-magnetic single-component toner (developer) to the photosensitive drum 31.

[0035] Supply roller 38 is provided between developing roller 37 and stirring paddle 333, and supplies non-magnetic one-component toner (developer) to the outer circumferential surface of developing roller 37. Stirring paddle 333 is provided in stirring chamber 335, and stirs the developer inside stirring chamber 335.

[0036] The side frame 63 rotatably supports the rotation shaft 39 of the developing roller 37 and the rotation shaft of the supply roller 38. One of the pair of side frames 63 is provided with a drive input gear 58 that inputs a rotational drive force to the rotation shaft 39 of the developing roller 37.

[0037] The drive input gear 58 is connected to the rotation shaft 39 of the developing roller 37 from the outside of the side frame 63 (not shown). When the developing device 33 is attached to the image forming apparatus 1, the drive input gear 58 is connected to a drive system (a gear train including a motor, etc.) provided at a predetermined position inside the image forming apparatus 1. In this state, the drive input gear 58 transmits the rotational drive force of the drive system to the rotation shaft 39 of the developing roller 37. As a result, the developing roller 37 rotates around the rotation shaft 39. A lubricant such as grease is applied to the drive input gear 58 to enable smooth transmission of the rotational drive force.

[0038] The guide portion 69 is a cylindrical protrusion protruding from the side frame 63 (the guide portion 69 is engageable with the guide rail 18). The developing device 33 is capable of moving 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.

[0039] The developing device 33 mounted in the main housing 10 at the mounting position P1 supplies toner to the outer peripheral surface of the photoconductor drum 31. This develops the electrostatic latent image formed on the outer peripheral surface of the photoconductor drum 31 (forming a toner image (visible image) that visualizes the electrostatic latent image).

[0040] As shown in Figures 2 and 3, around the container opening 60, there are provided 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, and a regulating blade 64 fixed to the rear end of the developing container 36.

[0041] The flat portion 62 is a plane that is connected 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 photoconductor 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.

[0042] 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.

[0043] Of both ends of the front and rear direction (direction perpendicular to the sheet width direction) of the front seal member 65, the end edge closer to the developing roller 37 (supply roller 38) is in contact with the entire developer-carrying area of ​​the outer circumferential surface of the developing roller 37 in the axial direction. The front seal member 65 closes the gap between the developing container 36 and the developing roller 37 by contacting the outer circumferential surface of the developing roller 37, thereby preventing the developer in the developing container 36 from flowing out.

[0044] The front seal member 65 has a shielding portion 19 that rises in the surface direction of the front seal member 65 from the edge farther from the developing roller 37 (supply roller 38) of both end edges in the front-rear direction (direction perpendicular to the sheet width direction). The shielding portion 19 protrudes upward over the entire axial area of ​​the edge of the front seal member 65. The shielding portion 19 has a rectangular shape formed from a sponge or the like, and is adhered to the surface of the front seal member 65 with an adhesive or the like. The shielding portion 19 holds the small amount of developer that leaks out from the gap between the developing roller 37 and the developing container 36 so that it does not fall outside the developing device 33.

[0045] The regulating blade 64 is a rectangular plate-like body formed elongated in the axial direction. The regulating blade 64 is provided in the upper part of the opening 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 arranged in contact with the outer circumferential surface of the developing roller 37. The toner supplied onto the developing roller 37 enters between the regulating blade 64 and the developing roller 37 as the developing roller 37 rotates, and is then frictionally charged and carried on the developing roller 37 as a thin layer of a certain thickness.

[0046] Fig. 4 is a perspective view of the cover member 50 as seen from the inside. Fig. 5 is a perspective view showing the entire developing device 33 with the cover member 50 attached. Fig. 6 is a cross-sectional view showing a cross section perpendicular to the axial direction of the developing device 33, taken at a position overlapping with the reinforcing rib 56 in the axial direction. Fig. 7 is a cross-sectional view showing a cross section perpendicular to the axial direction of the developing device 33, taken at a position overlapping with the engagement protrusion 57 in the axial direction.

[0047] The cover member 50 is detachably attached to the developing device 33 in the front-rear direction. As shown in FIGS. 4, 5, and 6, the cover member 50 is a rectangular box-shaped body made of resin and including a front surface portion 51, an upper surface portion 52, a lower surface portion 53, and side surfaces 54 and 55. The attachment direction of the cover member 50 to the developing container 36 (arrow L1 in FIG. 2) is hereinafter referred to as the "attachment direction." Also, the state in which the cover member 50 is attached to the developing container 36 is hereinafter simply referred to as the "attachment state."

[0048] The front surface portion 51 is a surface located at the upstream end of the cover member 50 in the mounting direction. The front surface portion 51 is composed of a flat surface portion 48 formed long and thin in the axial direction, and a curved portion 47 connected to a side edge extending along the axial direction of the flat surface portion 48 and curved along the outer circumferential surface of the developing roller 37. The flat surface portion 48 is a rectangular surface that is approximately perpendicular to the axial direction and the mounting direction. In the mounted state, the flat surface portion 48 faces the developing roller 37 and the shielding portion 19 in the front-rear direction. Also, in the mounted state, a gap is formed between the flat surface portion 48 and the shielding portion 19 in the front-rear direction. In the mounted state, the side edge (lower edge) in the axial direction of the flat surface portion 48 is located below the flat portion 62. Also, in the mounted state, the curved portion 47 faces the outer circumferential surface of the developing roller 37 in the radial direction of the developing roller 37.

[0049] The upper surface portion 52 and the lower surface portion 53 are flat plate-like bodies erected in the mounting direction from a side edge extending along the axial direction of the front surface portion 51. The upper surface portion 52 is connected to a side edge extending along the axial direction of the curved portion 47 (the side edge located opposite the flat portion 48). In the mounted state, the tip portion 46 of the upper surface portion 52 in the mounting direction (the end portion on the downstream side in the mounting direction) is located forward of the regulating blade 64.

[0050] The lower surface portion 53 is connected to a side edge (side edge opposite to the curved portion 47) along the axial direction of the flat portion 48. The lower surface portion 53 protrudes from a side edge of the front portion 51 in the mounting direction. In the mounted state, the tip portion 45 (downstream end portion in the mounting direction) of the lower surface portion 53 in the mounting direction is located forward of the shielding portion 19. The upper surface portion 52 and the lower surface portion 53 face each other in the vertical direction, sandwiching the developing roller 37 therebetween.

[0051] A plurality of reinforcing ribs 56 are formed in the connecting portion 44, which is an inner angle between the flat portion 48 and the lower surface portion 53, and are arranged in the axial direction. The reinforcing rib 56 is a flat plate-like body perpendicular to the axial direction. The reinforcing rib 56 protrudes from the lower surface portion 53 in its surface direction (upward) and from the flat portion 48 in its surface direction (mounting direction). In the mounted state, the downstream end of the reinforcing rib 56 in the mounting direction is located forward of the shielding portion 19. The upper end 43 of the reinforcing rib 56 (the tip of the lower surface portion 53 of the reinforcing rib 56 in the surface direction) is located further below the lower portion of the flat portion 62 of the developing container 36. That is, a gap is formed between the upper end 43 of the reinforcing rib 56 and the developing container 36 in the vertical direction.

[0052] The side portions 54, 55 protrude in the mounting direction from both axial ends of the front portion 51. The side portions 54, 55 extend in the up-down direction so as to connect the upper surface portion 52 and the lower surface portion 53. In the mounted state, the side portions 54, 55 are located outside both axial ends of the developing container 36. In other words, in the mounted state, the developing roller 37 is located between the side portions 54, 55 in the axial direction. Therefore, in the mounted state, the developing roller 37 is covered by the upper surface portion 52, the lower surface portion 53, and the side portions 54, 55.

[0053] One of the side portions 54 (the side portion on the near side of the paper in Figures 4, 5, and 6) has a gear opposing portion 61 that faces the drive input gear 58 in the axial direction when in the attached state. A portion of the gear opposing portion 61 protrudes in the attachment direction from the downstream end of the side portion 54 in the attachment direction. This protruding portion of the gear opposing portion 61 forms an arc shape in an axial plan view that follows the outer circumferential surface of the drive input gear 58. When in the attached state, the downstream end of the gear opposing portion 61 in the attachment direction (the above-mentioned protruding portion) is located forward of the drive input gear 58.

[0054] 4 and 7, a plurality of engagement protrusions 57 protruding in the mounting direction are provided on the downstream end edges in the mounting direction of the upper surface portion 52 and the lower surface portion 53 of the cover member 50. The downstream end portions in the mounting direction of the engagement protrusions 57 (claw portions) are claw-shaped.

[0055] An engagement recess 68 is formed in the developing container 36 in a portion below the flat portion 62 and in a portion above the container opening 60. The engagement recess 68 is recessed so as to be able to engage with the claw-shaped tip portion of the engagement protrusion 57. The engagement protrusion 57 and the engagement recess 68 constitute a snap-fit ​​mechanism (locking mechanism) that detachably connects the cover member 50 and the developing container 36 by engaging the claw-shaped tip portion of the engagement protrusion 57 with the engagement recess 68.

[0056] A grip portion 59 that is arc-shaped in a plan view and protrudes upward and rearward is provided on the upper surface portion 52. A user can attach / detach the cover member 50 to / from the developing container 36 by holding the grip portion 59.

[0057] As described above, when the cover member 50 is attached to the developing container 36, a gap is formed between the upper end 43 of the reinforcing rib 56 and the developing container 36. Therefore, even if vibration or impact is applied to the cover member 50 when the cover member 50 is attached to the developing container 36, the vibration or impact is unlikely to be transmitted to the developing container 36.

[0058] Therefore, it is possible to provide the developing device 33 capable of preventing the developer from flowing out even when the cover member 50 is attached.

[0059] As described above, the gear opposing portion 61 of the side portion 54 and the drive input gear 58 face each other in the axial direction, and the downstream end of the gear opposing portion 61 in the mounting direction is located forward of the drive input gear 58 in the axial direction. For this reason, when a user (including a maintenance worker or a transport worker) touches the developing device 33 with the cover member 50 attached, the user is less likely to directly touch the periphery of the drive input gear 58. As described above, a lubricant such as grease is applied to the drive input gear 58, and therefore, by adopting a configuration in which the gear opposing portion 61 faces the drive input gear 58 in the axial direction, it is possible to prevent the user's hands from getting dirty.

[0060] As described above, the shielding portion 19 is provided so as to protrude upward over 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 faces downward when attached to the main housing 10, the waste toner around the container opening 60 is blocked by the shielding portion 19. This makes it possible to prevent the waste toner from falling into the main housing 10.

[0061] Furthermore, as described above, when the cover member 50 is attached to the developing container 36, a gap is formed between the shielding portion 19 and the flat portion 48. Therefore, even if vibration or impact is applied to the cover member 50 when the cover member 50 is attached to the developing container 36, the vibration or impact is less likely to be transmitted to the developing container 36, and the outflow of developer can be more suitably suppressed. Also, even if waste toner has accumulated around the shielding portion 19, the waste toner can be prevented from scattering due to the impact applied to the cover member 50.

[0062] As described above, the reinforcing rib 56 is provided at the connecting portion 44 between the front surface portion 51 and the bottom surface portion 53. This makes it possible to improve the strength of the front surface portion 51 and the bottom surface portion 53 while suppressing thermal shrinkage during molding.

[0063] In addition, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention. For example, in the above embodiment, a monochrome printer is described as an example of the image forming apparatus 1, but the present invention can also be applied to, for example, a tandem type or rotary type color printer. The present invention can also be applied to image forming apparatuses such as copiers, facsimiles, or multifunction machines equipped with these functions.

[0064] In the above embodiment, the developer is a non-magnetic one-component developer made of only toner, but a two-component developer using toner and a carrier can also be used. [Industrial Applicability]

[0065] The present invention can be applied to a developing device that performs development using a developer containing a toner. By using the present invention, it is possible to prevent the developer from leaking out of the developing container during transportation or storage of the developing device. [Explanation of symbols]

[0066] 1. Image forming device 10 Main body housing (device main body) 19 Shielding part 30 Image forming section 31 Photoconductor drum (image carrier) 33 Developing device 36 Developer container 37 Developing roller (developer carrier) 39 Rotational Axis 44 Connecting part 50 Cover member 51 Front part 52 Top part 53 Bottom part 54, 55 Side part 56 Reinforcing rib 57 Engagement protrusion (claw part) 58 Drive input gear 60 Container opening (opening) 68 Engagement recess

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 supplies the toner to an image carrier in the development area; a cover member that is detachable from the developing container and protects an outer peripheral surface of the developer carrier exposed through the opening; In a developing device comprising: the cover member has a front surface portion that faces the entire area of ​​the developer carrier in the rotation axis direction, an upper surface portion and a lower surface portion that are erected toward the developing container side from side ends of the front surface portion that extend along the rotation axis direction and that face each other across the developer carrier, a side surface portion that is erected toward the developing container side from one end edge of the front surface portion in the rotation axis direction, and a reinforcing rib formed at a connecting portion between the lower surface portion and the front surface portion, and is detachably attached to the developing container so as to cover the developer carrier with at least the front surface portion and the upper surface portion, a seal member disposed along a rotation axis direction of the developer carrier at a position between the developer carrier and the front surface portion in a radial direction of the developer carrier, the seal member closing a gap between the developer carrier and the opening; a shielding portion that protrudes upward over an entire edge of the seal member on a side edge in the rotation axis direction that is farther from the developer carrier; Further equipped with A developing device characterized in that, when the cover member is attached to the developing container, a gap is formed between the reinforcing rib and the developing container, and a gap is formed between the front portion and the shielding portion.

2. a drive input gear that is connected to a rotation shaft of the developer carrier from the outside of the developing container and that inputs a rotational drive force to the developer carrier; The developing device according to claim 1 , wherein the side surface portion faces the drive input gear in the direction of the rotation axis.

3. 3. The developing device according to claim 1, wherein the shielding portion is a sponge.

4. The developing device according to any one of claims 1 to 3, further comprising a locking mechanism having a plurality of claw portions protruding from the cover member toward the developing container, and a plurality of engagement recesses formed in the developing container and capable of removably engaging with each of the claw portions.

5. 5. The developing device according to claim 1, wherein the developer is a non-magnetic one-component developer made of only non-magnetic toner.

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

Images