Developing device and image forming apparatus including the same

Abstract

The present invention provides a developing device and an image forming device including the developing device. The developing device includes a developing container, a developer carrier, a restricting blade, and a blade sealing member. The developing container has an opening portion and a blade opposing portion. The developer carrier has a developing area. The restricting blade has a fixing portion and a restricting portion. The blade sealing member is adhered to the surface on the upstream side in the rotational direction of the restricting portion.

Description

Technical Field

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

[0002] Image forming devices such as copiers, printers, fax machines, and their multifunction machines using an electrophotographic method include 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 (developer image) in which the electrostatic latent image is visualized.

[0003] The developing device includes a developing container and a developer carrier. The developing container houses a developer containing toner. The developing container has a container opening, and the container opening opens to the downstream side of the developing container in the moving direction of the developing device inside the image forming device when the developing device is installed in the image forming device. The developer carrier is arranged in contact with or close to the image carrier. The developer carrier carries the developer (toner) in the developing container on its outer peripheral surface.

[0004] The developer carrier is arranged to overlap with the container opening. A part of the developer carrier is exposed to the outside of the developing device through the container opening. The exposed part of the developer carrier that is exposed from the container opening faces the image carrier and forms a developing area. The developing area is an area for supplying the toner in the developing container to the image carrier.

[0005] As such a developing device, there is a developing device in which a restricting blade is arranged on the upstream side in the rotation direction of the developer carrier with respect to the developing area. The restricting blade protrudes toward the outer peripheral surface of the developer carrier over the entire area in the direction along the rotation axis of the developer carrier. The end of the restricting blade is in contact with or close to the outer peripheral surface of the developer carrier. The restricting blade restricts the layer thickness of the developer carried on the developer carrier.

[0006] The restricting blade is composed of a fixing part and a restricting part formed as a separate member. The fixing part is the part fixed to the developing container. The restricting part restricts the layer thickness of the developer on the developer carrier. The fixing part and the restricting part are integrated by joining with welding, an adhesive, etc. In order to improve the rigidity and strength of the fixing part, the thickness of the fixing part is greater than the thickness of the restricting part. Therefore, a stepped shape is formed from the fixing part to the restricting part, and the distance from the fixing part to the developing container is smaller than the distance from the restricting part to the developing container.

[0007] In such a developing device, a blade sealing member is arranged between the restricting blade and the developing container. The blade sealing member blocks the gap between the restricting blade and the developing container and suppresses the outflow of the developer. Summary of the Invention

[0008] An object of the present invention is to provide a developing device capable of suppressing the outflow of the developer.

[0009] The developing device of the first structure of the present invention includes: a developing container having an opening and accommodating a developer containing toner therein; a developer carrier rotatably supported by the developing container, a part of the outer peripheral surface of the developer carrier for carrying the developer having a developing area exposed from the opening and facing an image carrier, and supplying the toner to the image carrier in the developing area; and a restricting blade disposed upstream of the developing area in the rotation direction of the developer carrier to restrict the layer thickness of the developer carried by the developer carrier. Among them, the developing container has a blade opposing portion opposing the surface on the upstream side in the rotation direction of the restricting blade, the developing device includes a blade sealing member disposed between the restricting blade and the blade opposing portion to block the gap between the restricting blade and the blade opposing portion. The restricting blade has a fixing portion and a restricting portion. The fixing portion is opposed to the blade opposing portion and fixed to the developing container. The restricting portion protrudes from the fixing portion toward the developer carrier. The interval between the restricting portion and the blade opposing portion is greater than the interval between the fixing portion and the blade opposing portion. The blade sealing member is adhered to the surface on the upstream side in the rotation direction of the restricting portion.

[0010] The image forming device of the second structure of the present invention includes: a device main body; the image carrier disposed inside the device main body and forming an electrostatic latent image on the outer peripheral surface; and the developing device of the above structure detachably disposed inside the device main body. In a state where the developing device is installed inside the device main body, the developer carrier contacts or approaches the outer peripheral surface of the image carrier to develop the electrostatic latent image into a toner image.

[0011] According to the first structure of the present invention, the blade sealing member is adhered to the restricting portion. Therefore, even if the restricting blade is slightly inclined, it is difficult for a gap to be generated between the blade sealing member and the restricting blade, and the outflow of the developer can be suppressed. Even if the restoring force at the contact portion in contact with the restricting portion is relatively small, it is difficult for a gap to be generated between the sealing member and the restricting portion. Thus, it is difficult for the developer to flow out of the developing container.

[0012] In addition, according to the second structure of the present invention, an image forming device capable of suppressing the outflow of the developer can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a side sectional view showing a schematic structure of the image forming device 1 of the present invention.

[0014] Figure 2 It is a perspective view showing the whole developing device 33.

[0015] Figure 3It is an enlarged cross-sectional view that magnifies the peripheral portions of the photosensitive drum 31 and the developing device 33.

[0016] Figure 4 It shows the developing device 33 in a state where the developing roller 37 (refer to Figure 2 ), the restricting blade 64 (refer to Figure 2 ), and the bushing cover 63 (refer to Figure 2 ) are removed from the developing container 36.

[0017] Figure 5 It is a side cross-sectional view of the developing device 33 cut along the cutting plane line A-A shown by Figure 4 .

[0018] Figure 6 It is a perspective view showing the blade seal member 67.

[0019] Figure 7 It is a partial enlarged view that magnifies the peripheral portion of the end of the blade seal member 67 of the developing device 33 (the area surrounded by the double-dashed circle B of Figure 4 ).

[0020] Figure 8 It is a partial enlarged view that magnifies the cross-section of the periphery of the restricting blade 64 (the area surrounded by the double-dashed circle C of Figure 3 ). Detailed Embodiments

[0021] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Figure 1 It is a side cross-sectional view showing the schematic structure of the image forming apparatus 1 of the present invention. In addition, in Figure 1 , the right side shown in the figure is set as the front side of the image forming apparatus 1, and the left side shown in the figure is set as the rear side of the image forming apparatus 1. Furthermore, in Figure 1 , the upper side shown in the figure is set as the upper side of the image forming apparatus 1, and the lower side shown in the figure is set as the lower side of the image forming apparatus 1.

[0022] As Figure 1 shows, the image forming apparatus 1 (here, a black-and-white printer) includes a main body housing 10 (apparatus main body), a paper feeding unit 20, an image forming unit 30, and a fixing unit 40. The main body housing 10 has a frame structure in a substantially rectangular parallelepiped shape. The paper feeding unit 20 is housed in the main body housing 10.

[0023] The main body casing 10 is provided with a front cover 11, a rear cover 12, a main body opening 15, and an upper cover 16. The front cover 11 is located on the front surface side of the main body casing 10. The rear cover 12 is located on the rear surface side of the main body casing 10. The main body opening 15 is formed above the main body casing 10. The upper cover 16 is provided on the upper surface of the main body casing 10. The upper cover 16 can open and close the main body opening 15. By opening the upper cover 16, it is possible to enter the interior of the main body casing 10 via the main body opening 15.

[0024] On the upper surface of the upper cover 16, there is a paper discharge portion 13 for discharging the sheet body (recording medium) after image formation. In the upper part of the main body casing 10, a paper discharge port 14 is provided so as to face the paper discharge portion 13 in the front-rear direction. The paper discharge port 14 is an opening communicating with the interior of the main body casing 10. In addition, in the following description, the term "sheet body" refers to copy paper, coated paper, film copy paper, thick paper, postcards, tracing paper, and other sheet materials that are subjected to image formation processing.

[0025] In a state where the upper cover 16 is open, the developing device 33 can enter and exit the main body casing 10 from the main body opening 15. In a state where the rear cover 12 is open, each unit of the image forming portion 30 and the fixing portion 40 (except for the developing device 33) can enter and exit from the rear surface side of the main body casing 10.

[0026] The paper supply unit 20 includes a paper supply cassette 21. The paper supply cassette 21 houses the sheet body for performing image formation processing. A part of the paper supply cassette 21 protrudes further forward from the front surface of the main body casing 10. The upper surface of the portion of the paper supply cassette 21 housed within the main body casing 10 is covered by a paper supply cassette top plate 21U.

[0027] The paper supply cassette 21 has a paper storage space for storing a stack of sheet bodies, and a lifting plate for lifting the stack of sheet bodies for paper supply. A paper extraction portion 21A is provided at the upper part on the rear end side of the paper supply cassette 21. The paper extraction portion 21A is provided with a paper supply roller 21B that extracts one by one the uppermost sheet body of the stack of sheet bodies in the paper supply cassette 21.

[0028] The image forming portion 30 performs an image forming operation. The image forming operation is an operation of forming a toner image (developer image) on the sheet body sent out from the paper supply unit 20. The image forming portion 30 includes a photosensitive drum 31 and a charging portion 32, an exposure portion 35, a developing device 33, and a transfer roller 34 arranged around the photosensitive drum 31. The developer for image formation is a non-magnetic one-component developer composed only of toner.

[0029] The photosensitive drum 31 (image carrier) includes a rotating shaft and an outer peripheral surface that rotates around the rotating shaft. The photosensitive drum 31 is constituted by, for example, a known organic (OPC) photoreceptor, and a photosensitive layer composed of a charge generation layer, a charge transport layer, etc. is formed on the outer peripheral surface. After the photosensitive layer is uniformly charged by the charging unit 32 described later, light is irradiated by the exposure unit 35 to form an electrostatic latent image with reduced charge, and the developing device 33 carries the toner image on which the electrostatic latent image is developed.

[0030] The charging unit 32 (charging device) is disposed at a predetermined interval from the outer peripheral surface of the photosensitive drum 31 to uniformly charge the outer peripheral surface of the photosensitive drum 31 in a non-contact state. Specifically, the charging unit 32 has a charging wire 321 and a grid electrode 322 (both are referred to Figure 3 ). The charging wire 321 is a linear electrode extending in the rotating shaft direction of the photosensitive drum 31, and corona discharge is generated between the charging wire 321 and the photosensitive drum 31. The grid electrode 322 is a grid-shaped electrode extending in the rotating shaft direction of the photosensitive drum 31, and is disposed between the charging wire 321 and the photosensitive drum 31.

[0031] The charging unit 32 generates corona discharge by passing a current of a predetermined current value through the charging wire 321, and uniformly charges the outer peripheral surface of the photosensitive drum 31 opposite to the grid electrode 322 to a predetermined surface potential by applying a predetermined voltage to the grid electrode 322.

[0032] The exposure unit 35 (exposure device) has optical system devices such as a laser light source, a mirror, and a lens. The exposure unit 35 irradiates the outer peripheral surface of the photosensitive drum 31 with light modulated according to image data from an external device such as a personal computer. Thereby, the exposure unit 35 forms an electrostatic latent image corresponding to the image based on the image data on the outer peripheral surface of the photosensitive drum 31.

[0033] The transfer roller 34 has a rotating shaft parallel to the width direction of the sheet body and an outer peripheral surface facing the outer peripheral surface of the photosensitive drum 31. The transfer roller 34 is supported by the main body housing 10 so as to be rotatable around the rotating shaft. The transfer roller 34 transfers the toner image carried on the outer peripheral surface of the photosensitive drum 31 to the sheet body passing through the nip portion between the transfer roller 34 and the outer peripheral surface of the photosensitive drum 31. At the time of the transfer, a transfer voltage having a polarity opposite to that of the toner is applied to the transfer roller 34.

[0034] The fixing unit 40 is located downstream of the transfer roller 34 in the sheet conveyance direction, and fixes the toner image transferred onto the sheet onto the sheet. The fixing unit 40 includes a fixing roller 41 and a pressure roller 42. The fixing roller 41 has a heating source inside, and heats the toner transferred onto the sheet to a predetermined temperature. The pressure roller 42 is in pressure contact with the fixing roller 41, and a fixing nip portion is formed between the pressure roller 42 and the fixing roller 41. If the sheet onto which the toner image is transferred is conveyed to the fixing nip portion, the toner image is fixed onto the sheet by the heating of the fixing roller 41 and the pressing of the pressure roller 42.

[0035] Inside the main body housing 10, a main conveyance path 22F and a reverse conveyance path 22B are provided. The main conveyance path 22F and the reverse conveyance path 22B convey the sheet. The main conveyance path 22F extends from the paper extraction portion 21A of the paper supply unit 20, via the image forming unit 30 and the fixing unit 40, to the paper discharge port 14. The reverse conveyance path 22B is a conveyance path that, in the case of double-sided printing on the sheet, is used to return the sheet after single-sided printing to the upstream side of the image forming unit 30 in the main conveyance path 22F.

[0036] The main conveyance path 22F extends upward from below through the transfer nip portion formed by the photosensitive drum 31 and the transfer roller 34. In addition, a pair of registration rollers 23 is disposed on the upstream side of the transfer nip portion in the main conveyance path 22F. The sheet is temporarily stopped by the pair of registration rollers 23, and after skew correction, is sent out to the transfer nip portion at a predetermined timing for image transfer. A plurality of conveyance rollers for conveying the sheet are disposed in the main conveyance path 22F and the reverse conveyance path 22B. A pair of paper discharge rollers 24 is disposed near the paper discharge port 14.

[0037] The reverse conveyance path 22B is formed between the outer side surface of the reverse unit 25 and the inner surface of the rear cover 12 of the main body housing 10. In addition, the transfer roller 34 and one of the pair of registration rollers 23 are loaded on the inner side surface of the reverse unit 25. The rear cover 12 and the reverse unit 25 can each rotate about the axis of the fulcrum portion 121 provided at their lower ends. When a paper jam occurs in the reverse conveyance path 22B, the rear cover 12 is opened. When a paper jam occurs in the main conveyance path 22F, or when the unit of the photosensitive drum 31 and the developing device 33 are taken out to the outside, in addition to opening the rear cover 12, the reverse unit 25 is also opened.

[0038] As Figure 1 shown, guide rails 18 are formed on a pair of side surfaces 17 in the main body housing 10 that face the width direction of the sheet ( Figure 1 the paper surface direction). The guide rails 18 have an orbital structure that is recessed in the width direction of the sheet. The guide rails 18 extend downward from the main body opening 15 to the installation position P1 where the developing device 33 is installed with respect to the main body housing 10.

[0039] Figure 2 is a perspective view showing the entire developing device 33. Figure 3 is an enlarged cross-sectional view of the peripheral portions of the photosensitive drum 31 and the developing device 33. Figure 4 is a top view showing the developing device 33 with the developing roller 37 (see Figure 2 ), the restricting blade 64 (see Figure 2 ), and the bushing cover 63 (see Figure 2 ) removed.

[0040] As shown in Figure 2 , Figure 3 , Figure 4 , the developing device 33 includes a developing container 36, a developing roller 37 (developer carrier), a supply roller 38, a stirring blade 333, and a guide portion 69.

[0041] The developing container 36 houses a non-magnetic one-component developer composed only of toner therein, and houses the developing roller 37, the supply roller 38, etc. The developing container 36 has a stirring chamber 335, a container opening 60 (opening portion), and a bushing cover 63. The stirring chamber 335 houses the developer in a stirred state.

[0042] The container opening 60 is located more rearward in the front-rear direction than the stirring chamber 335. The container opening 60 is a rectangular through-hole opened on the rear side (the side close to the photosensitive drum 31) of the developing container 36. The container opening 60 is formed in an elongated shape in the width direction (axial direction) of the developing device 33.

[0043] The developing roller 37 is disposed inside the container opening 60 so as to overlap the container opening 60. A part of the outer peripheral 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 rotating shaft 39 extending along the width direction of the developing device 33 (the width direction of the sheet-like body). The rotating 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 rotating shaft 39 and can rotate in the left rotation shown in the figure (see Figure 3 ) with the rotating shaft 39 as the center. Hereinafter, the direction along the rotating shaft 39 will be referred to as the "axial direction (rotating shaft direction)". In addition, the rotation direction of the developing roller 37 around the rotating shaft 39 will be referred to as the "rotation direction".

[0044] The developing roller 37 can carry toner on its outer peripheral surface. When the developing device 33 is located at the installation position P1, the portion of the developing roller 37 exposed from the container opening 60 contacts, or approaches and faces, the outer peripheral surface of the photosensitive drum 31. In the above state, the developing roller 37 can supply the non-magnetic one-component toner (developer) to the photosensitive drum 31.

[0045] The supply roller 38 is disposed between the developing roller 37 and the stirring blade 333. The supply roller 38 supplies non-magnetic one-component toner (developer) to the outer peripheral surface of the developing roller 37. The stirring blade 333 is disposed in the stirring chamber 335 and stirs the developer inside the stirring chamber 335.

[0046] The bushing covers 63 are detachably attached to both ends of the developing container 36 in the width direction of the sheet body. The bushing covers 63 constitute the side wall portions of the developing container 36. The bushing covers 63 are formed with a plurality of through holes penetrating in the axial direction, and the rotary shafts 39 of the developing roller 37 and the supply roller 38 are inserted into the through holes, and the developing roller 37 and the supply roller 38 are supported rotatably.

[0047] The guide portion 69 is a cylindrical protrusion protruding from the bushing cover 63. The guide portion 69 can be engaged with the guide rail 18. By engaging the guide portion 69 with the guide rail 18, the developing device 33 can move along the guide rail 18 between the main body opening 15 and the mounting position P1.

[0048] In a state where the developing device 33 is mounted on the main body housing 10 at the mounting position P1, toner is supplied to the outer peripheral surface of the photosensitive drum 31. Thereby, the electrostatic latent image formed on the outer peripheral surface of the photosensitive drum 31 is developed (a toner image (visible image) in which the electrostatic latent image is manifested is formed).

[0049] As Figure 2 、 Figure 4 shown, a pressing member 43, a flat portion 62, a front sealing member 65, a restricting blade 64, and a blade sealing member 67 are provided around the container opening 60. The pressing member 43 is disposed at both axial ends of the developing roller 37. The flat portion 62 is located more rearward (closer to the photosensitive drum 31 side) than the container opening 60. The front sealing member 65 is disposed on the flat portion 62. The restricting blade 64 is fixed to the rear end portion of the developing container 36. The blade sealing member 67 is laminated on the back side of the restricting blade 64.

[0050] Figure 5 is the side sectional view of the developing device 33 cut along the cutting line A-A shown in Figure 4 . Figure 6 is a perspective view showing the blade sealing member 67. Figure 7 is a partial enlarged view of the periphery of the end portion of the blade sealing member 67 of the developing device 33 (the region surrounded by the double-dot chain line circle B shown in Figure 4 ). In addition, the blade sealing member 67 shown in Figure 6 is shown in a state where the blade sealing member 67 shown in Figure 4 is turned over in the front-rear direction, and Figure 4 and Figure 6 are opposite in the left-right direction.

[0051] The pressing member 43 is axially located at a position overlapping with both end portions of the container opening 60 (see Figure 2 ). As Figure 5 shown, the pressing member 43 has a pressing surface 44. The pressing surface 44 is a surface that is curved so as to be recessed forward (toward the stirring chamber 335 side) along the outer peripheral surface of the developing roller 37. The pressing surface 44 faces the outer peripheral surfaces of both end portions 66 of the developing roller 37 in the radial direction of the developing roller 37.

[0052] The thickness of the pressing member 43 is formed to be greater than the gap between the outer peripheral surface of the developing roller 37 and the inner surface of the developing container 36. Thus, when the developing roller 37 is installed in the developing container 36, the pressing surface 44 contacts the outer peripheral surface of the developing roller 37 and presses the developing roller 37 in the radial direction of the developing roller 37. By contacting and pressing both end portions 66, the pressing surface 44 blocks the gap between both end portions 66 and the developing container 36, suppressing the outflow of the developer from inside the developing container 36.

[0053] The pressing member 43 has a multi-layer structure in which a plurality of thin sheet members are laminated (here, a two-layer structure), and the plurality of thin sheet members are laminated in the radial direction of the developing roller 37. At least the thin sheet member closest to the developing roller 37 in the radial direction among the multi-layer thin sheet members is a thin sheet member of polytetrafluoroethylene (so-called Teflon). The above-mentioned pressing surface 44 is formed on the surface of the thin sheet member. The other thin sheet members among the multi-layer thin sheet members are formed of polyurethane foam such as sponge.

[0054] Returning to Figure 2 , Figure 3 , the flat portion 62 is a flat surface connected to a portion of the inner surface of the developing container 36 located below the developing roller 37. The flat portion 62 extends rearward (toward the direction close to the photosensitive drum 31) from the container opening 60. When the developing device 33 is at the installation position P1, the flat portion 62 is substantially horizontal.

[0055] The front sealing member 65 is a rectangular thin sheet formed of a PET film or the like. The front sealing member 65 is laminated above the flat portion 62 and adhered to the developing container 36 with an adhesive or the like. The front sealing member 65 is axially formed to be elongated. The front sealing member 65 extends between both end portions 66 of the developing roller 37 along the axial direction.

[0056] Both end edges of the front sealing member 65 in the front-rear direction (the direction orthogonal to the width direction of the thin sheet body) on the side close to the developing roller 37 (supply roller 38) contact the entire region of the outer peripheral surface of the developing roller 37 that carries the developer in the axial direction. The front sealing member 65 blocks the gap between the developing container 36 and the developing roller 37 by contacting the outer peripheral surface of the developing roller 37, suppressing the outflow of the developer in the developing container 36.

[0057] The front sealing member 65 has a first shielding portion 19. The first shielding portion 19 stands up from the end edge on the side far from the developing roller 37 (supply roller 38) among the end edges in the front-rear direction (the direction orthogonal to the width direction of the sheet body) toward the surface direction of the front sealing member 65. The first shielding portion 19 projects upward across the entire axial region of the end edge of the front sealing member 65. The first shielding portion 19 is square formed of a sponge or the like. The first shielding portion 19 is adhered to the surface of the front sealing member 65 with an adhesive or the like. The first shielding portion 19 holds the developer that slightly flows out from the gap between the developing roller 37 and the developing container 36 so as not to fall outside the developing device 33.

[0058] On the outer sides of the axial end portions of the first shielding portion 19, there are provided plate-shaped second shielding portions 53 that project upward. The second shielding portions 53 are located at positions overlapping with the pressing member 43 in the axial direction. The second shielding portions 53 are integrally formed with the bushing cover 63. In a state where the bushing cover 63 is attached to the developing container 36, the second shielding portions 53 extend along the axial direction from the bushing cover 63 to approach the first shielding portion 19.

[0059] Figure 8 is a partial enlarged view showing an enlarged cross section of the periphery of the restricting blade 64 (the region surrounded by the Figure 3 circular C of the double-dot chain line).

[0060] As Figure 8 shown, the developing container 36 has a blade opposing portion 45. The blade opposing portion 45 is located in the upper portion of the opening edge of the container opening 60. The blade opposing portion 45 opposes the surface on the upstream side in the rotation direction of the restricting blade 64 (the front surface in the front-rear direction). The blade opposing portion 45 is formed flat in the axial direction.

[0061] The restricting blade 64 is a plate-like body that is elongated in the axial direction and formed into a rectangle (refer to Figure 2 ). The restricting blade 64 is configured to include a fixing portion 46 and a restricting portion 47. The fixing portion 46 is a plate-like body made of metal in a side view L shape having a bent portion bent at approximately a right angle. The fixing portion 46 is arranged to oppose the blade opposing portion 45 in the rotation direction.

[0062] The restricting portion 47 is a plate-like body made of metal that is elongated in the axial direction and formed into a rectangle. The upper end portion of the restricting portion 47 is laminated and welded to the surface on the downstream side in the rotation direction (the photosensitive drum 31 side) of the fixing portion 46. The restricting portion 47 projects from the lower end portion of the fixing portion 46 (in the up-down direction, the end portion of the fixing portion 46 closest to the developing roller 37) toward the developing roller 37.

[0063] The end portion in the protruding direction of the restricting portion 47 is arranged to contact the outer peripheral surface of the developing roller 37. The toner supplied onto the developing roller 37 enters between the restricting portion 47 and the developing roller 37 as the developing roller 37 rotates, and then while triboelectrically charging, it is carried on the developing roller 37 as a thin layer with a fixed thickness.

[0064] As Figure 8 shown, the thickness of the restricting portion 47 ( Figure 8 the dimension in the front - rear direction) is smaller than the thickness of the fixing portion 46. That is, the interval L2 in the thickness direction between the restricting portion 47 and the blade - facing portion 45 is larger than the interval L1 in the thickness direction between the fixing portion 46 and the blade - facing portion 45.

[0065] At the laminated portion of the fixing portion 46 and the restricting portion 47 in the restricting blade 64, a through - hole is formed that penetrates the fixing portion 46 and the restricting portion 47 in the plane direction (thickness direction) of the fixing portion 46. The fixing portion 46 is fixed to the blade - facing portion 45 by a connecting member 48 composed of a nut and a bolt passing through the through - hole.

[0066] As Figure 8 shown, in the rotational direction (the direction orthogonal to the axial direction), a blade sealing member 67 is provided between the restricting blade 64 and the developing container 36. The blade sealing member 67 is axially arranged between a pair of pressing members 43 (refer to Figure 4 ). The blade sealing member 67 is composed of multiple thin sheets including a first laminated body 70 and a second laminated body 71 laminated in the front - rear direction.

[0067] The first laminated body 70 is formed in a square shape from a sponge such as PORON. The first laminated body 70 is axially formed to be elongated. The two axial end portions of the first laminated body 70 are in pressure contact (contact and press) with the respective pressing members 43 (refer to Figure 4 ). The first laminated body 70 is laminated on the surface of the fixing portion 46 and the restricting portion 47 on the side away from the photosensitive drum 31 (the upstream side surface in the rotational direction of the developing roller 37). On the surface of the first laminated body 70 on the downstream side in the rotational direction (the rear side in the front - rear direction), a double - sided tape with an adhesive component on both sides is pasted. In other words, the double - sided tape is arranged between the first laminated body 70 and the restricting portion 47. The first laminated body 70 is bonded to the restricting portion 47 by the double - sided tape.

[0068] The first laminated body 70 is pressed and compressed by the fixing portion 46 and the restricting portion 47 toward the blade - facing portion 45. The compression amount of the portion of the first laminated body 70 located between the fixing portion 46 and the blade - facing portion 45 is larger than the compression amount of the portion of the first laminated body 70 located between the restricting portion 47 and the blade - facing portion 45.

[0069] The dimensions of the first laminate 70 in the vertical direction in the state before being disposed between the restricting squeegee 64 and the squeegee opposing portion 45 (state before compression) and in the state after being disposed (state after compression) are formed to be larger than the dimensions in the thickness direction (front-rear direction). In other words, the cross-section of the first laminate 70 orthogonal to the axial direction is elongated in the vertical direction.

[0070] As Figure 4 , Figure 6 shown, the first laminate 70 is composed of a first sealing member 72 and a second sealing member 73 arranged axially with respect to each other. A connecting portion 74 is formed at the opposing portion between the first sealing member 72 and the second sealing member 73.

[0071] The first sealing member 72 is formed with a first protrusion 77 and a first recess 76. The first protrusion 77 and the first recess 76 are axially provided at the end portion located on the central side of the container opening 60. The first protrusion 77 protrudes from the end portion of the first sealing member 72 toward the axial direction. The first recess 76 is recessed from the end of the protruding direction of the first protrusion 77 toward the direction opposite to the protruding direction. The first protrusion 77 and the first recess 76 are adjacent in the direction orthogonal to the axial direction.

[0072] The second sealing member 73 is formed with a second protrusion 75 and a second recess 78. The second protrusion 75 and the second recess 78 are axially provided at the end portion located on the central side of the container opening 60. The second protrusion 75 protrudes from the end portion of the second sealing member 73 toward the axial direction. The second recess 78 is recessed from the end of the protruding direction of the second protrusion 75 toward the direction opposite to the protruding direction. The second protrusion 75 and the second recess 78 are adjacent in the direction orthogonal to the axial direction.

[0073] The second protrusion 75 overlaps the first recess 76 in the direction orthogonal to the axial direction (vertical direction). The length from the bottom of the second recess 78 to the end of the second protrusion 75 is equal to or slightly smaller than the length from the bottom of the first recess 76 to the end of the first protrusion 77. The first protrusion 77 is inserted into the second recess 78, and the second protrusion 75 is inserted into the first recess 76.

[0074] The connecting portion 74 is composed of the first protrusion 77, the first recess 76, the second protrusion 75, and the second recess 78. The connecting portion 74 axially joins the first sealing member 72 and the second sealing member 73 using an adhesive coated to block the space between the first protrusion 77 and the second recess 78 and to block the space between the first recess 76 and the second protrusion 75.

[0075] The second laminate 71 is a thin sheet material that is axially elongated. The second laminate 71 is formed of polyethylene terephthalate (PET). The rigidity of the second laminate 71 is greater than that of the first laminate 70. As Figure 5 , Figure 6 shown, the second laminate 71 is laminated on the surface of the first laminate 70 on the side opposite to the contact surface in contact with the restricting blade 64 (the surface farther from the developing roller 37 in the front-rear direction). The second laminate 71 is adhered to the first laminate 70 with an adhesive or the like. One second laminate 71 is laminated on each of the first sealing member 72 and the second sealing member 73, respectively.

[0076] The axial length of the second laminate 71 is shorter than the axial length of the blade sealing member 67. Axially, the both ends of the second laminate 71 are located more inwardly than the both ends of the blade sealing member 67. In the region from the axial both ends of the blade sealing member 67 to the both ends of the second laminate 71, a buffer portion 68 where the first laminate 70 protrudes from the second laminate 71 is formed.

[0077] The second laminate 71 is provided with sealing-side positioning protrusions 79 (positioning protrusions) that are more inward in the axial direction than the both ends and are respectively provided at axially symmetric positions. The sealing-side positioning protrusions 79 protrude more outward in the axial direction and the up-down direction than the edge portion of the blade sealing member 67 (refer to Figure 7 ).

[0078] As Figure 4 , Figure 7 shown, container-side positioning protrusions 80 are respectively formed at both axial ends of the container opening 60. The container-side positioning protrusions 80 protrude downward from a part of the inside of the developing container 36. A facing surface 81 is formed on the surface of the container-side positioning protrusion 80 on the side closer to the center of the container opening 60 in the axial direction. The facing surfaces 81 of the respective container-side positioning protrusions 80 sandwich a part of the blade sealing member 67 and are opposed to each other in the axial direction.

[0079] The sealing-side positioning protrusions 79 are located inward in the axial direction of the respective container-side positioning protrusions 80. The sealing-side positioning protrusions 79 and the container-side positioning protrusions 80 are located at positions overlapping in the up-down direction. The sealing-side positioning protrusions 79 are opposed to the container-side positioning protrusions 80 in the axial direction. By the contact between the sealing-side positioning protrusions 79 and the container-side positioning protrusions 80, the second laminate 71 is positioned in the axial direction.

[0080] As described above, the first laminate 70 is adhered to the restricting portion 47. Therefore, even if the restricting blade 64 is slightly inclined, it is difficult for a gap to be generated between the restricting portion 47 and the first laminate 70, and the outflow of the developer can be suppressed.

[0081] In addition, as described above, the amount of compression of the portion of the first laminate 70 between the fixing portion 46 and the blade facing portion 45 is greater than the amount of compression of the portion of the first laminate 70 between the restricting portion 47 and the blade facing portion 45. That is, the restoring force of the portion of the first laminate 70 between the restricting portion 47 and the blade facing portion 45 is smaller than the restoring force of the portion of the first laminate 70 between the fixing portion 46 and the blade facing portion 45. However, since the first laminate 70 is adhered to the restricting portion 47, it is difficult for a gap to be generated between the first laminate 70 and the restricting portion 47. Therefore, it is difficult for the developer to flow out of the developing container 36.

[0082] Therefore, it is possible to provide a developing device 33 that appropriately restricts the layer thickness of the developer on the developing roller 37 and can suppress the outflow of the developer.

[0083] In addition, the first laminate 70 is formed such that the dimension in the vertical direction of the first laminate 70 in the compressed state is larger than the dimension in the thickness direction, and the first laminate 70 is laminated on the fixing portion 46 and the restricting portion 47. That is, the first laminate 70 and the restricting blade 64 are in contact with each other over a relatively large range in the vertical direction. Then, the pressing force of the restricting blade 64 on the blade facing portion 45 can be suppressed to a magnitude that stabilizes the restricting blade 64, and tilting of the restricting blade 64 can be suppressed. Therefore, it is possible to further appropriately suppress the outflow of the developer and avoid a situation where the restricting blade 64 tilts and the layer thickness of the developer on the developing roller 37 cannot be appropriately restricted.

[0084] In addition, as described above, the rigidity of the second laminate 71 is greater than the rigidity of the first laminate 70. Therefore, when the second laminate 71 is adhered to the first laminate 70, it is difficult for the second laminate 71 to generate wrinkles and creases, and it is difficult for a gap to be generated between the second laminate 71 and the developing container 36 (blade facing portion 45).

[0085] Moreover, since the second laminate 71 having a relatively large rigidity is laminated and adhered to the first laminate 70, the second laminate 71 becomes a support member, and it is difficult for the first laminate 70 to bend. Therefore, when the first laminate 70 is adhered to the restricting blade 64 (fixing portion 46 and restricting portion 47), wrinkling and bending of the bonding surface of the first laminate 70 adhered to the restricting portion 47 can be suppressed. Therefore, it is difficult for a gap to be generated between the first laminate 70 and the restricting portion 47, and the outflow of the developer can be further appropriately suppressed.

[0086] In addition, as described above, the second laminate 71 is positioned by the contact between the sealing-side positioning protrusion 79 and the opposing surface 81. Since the rigidity of the second laminate 71 is greater than that of the first laminate 70, the positioning of the blade sealing member 67 can be easily performed by the contact between the sealing-side positioning protrusion 79 and the opposing surface 81. Here, the second laminate 71 is laminated and adhered to the first laminate 70, and by positioning the second laminate 71, the first laminate 70, that is, the blade sealing member 67, is positioned. In this state, since the first laminate 70 is in pressure contact with the pressing member 43, the axial gap between the developing container 36 and the blade sealing member 67 is blocked by the pressing member 43, and the outflow path of the developer can be blocked.

[0087] In addition, as described above, the both end portions of the second laminate 71 are more located on the inner side in the axial direction than the both end portions of the first laminate 70, and a buffer portion 68 is formed in a portion of the first laminate 70 from the both end portions of the second laminate 71 to the both end portions of the first laminate 70. Therefore, when the blade sealing member 67 is positioned and the both end portions of the first laminate 70 come into contact with the pressing member 43, the buffer portion 68 is compressed. Then, the compression ratio of the portion (buffer portion 68) of the first laminate 70 that comes into contact with the pressing member 43 increases, and the sealing performance between the first laminate 70 and the pressing member 43 can be improved. Therefore, the outflow of the developer can be suppressed more favorably.

[0088] In addition, as described above, the first laminate 70 connects the separately formed first sealing member 72 and second sealing member 73 through the connecting portion 74. Moreover, the second laminate 71 is laminated on the first sealing member 72 and the second sealing member 73, respectively. Therefore, when the blade sealing member 67 is axially arranged between a pair of pressing members 43, it can be arranged in a state where there is play (gap) between each pressing member 43 and the first sealing member 72 and the second sealing member 73. In this state, the first sealing member 72 and the second sealing member 73 can be adhered with an adhesive at an interval that generates a predetermined contact pressure between the blade sealing member 67 and the pressing member 43. As a result, the assemblability is improved, and the manufacturing cost of the developing device 33 can be suppressed.

[0089] Moreover, a first shielding portion 19 protruding upward is provided over the entire region of the end edge in the long side direction of the front sealing member 65. Therefore, even if waste toner accumulates around the container opening 60, when the developing device 33 is installed in the main body casing 10 with the developing device 33 facing downward, the waste toner around the container opening 60 is blocked by the first shielding portion 19. Therefore, the waste toner can be prevented from falling into the main body casing 10.

[0090] Therefore, it is possible to provide a developing device 33 that can suppress the outflow of the developer from the gap between the developing roller 37 and the developing container 36 and can suppress the developer from falling inside the main body casing 10 from the periphery of the container opening portion 60 of the developing device 33.

[0091] In addition, as described above, the second shielding portion 53 is axially located at a position overlapping with the pressing member 43. Therefore, even if a small amount of the developer flows out from the gap between the pressing member 43 and the developing roller 37, it will be blocked by the second shielding portion 53 from flowing out to the outside of the developing container 36. In addition, as described above, the second shielding portion 53 is integrally formed with the bushing cover 63. Therefore, when the bushing cover 63 is installed, the second shielding portion 53 is also positioned at a predetermined position. Therefore, the assembly man-hours can be reduced and the manufacturing cost can be suppressed.

[0092] In addition, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. For example, in the above-described embodiment, a black-and-white printer is illustrated as an example of the image forming apparatus 1, but for example, it can also be applied to tandem and rotary color printers. In addition, it can also be applied to image forming apparatuses such as copiers, facsimile machines, or multifunction machines having their functions.

[0093] In addition, as described above, the first laminate 70 is bonded to the restricting portion 47, but it may also be bonded to the fixing portion 46 in addition to this.

[0094] In addition, the blade sealing member 67 may have a structure composed only of the first laminate 70 without the second laminate 71. In this case, a structure in which the surface of the first laminate 70 opposite to the restricting blade 64 is bonded to the blade opposing portion 45 can be adopted.

[0095] In addition, in the above-described embodiment, the first shielding portion 19 is formed of sponge, but it is not limited thereto and may be made of other materials. In addition, the first shielding portion 19 may have a structure in which it is integrally formed with the front sealing member 65 and is bent to stand up upward from the end edge of the front sealing member 65. In this case, the number of parts of the front sealing member 65 is reduced, and the manufacturing cost can be suppressed.

[0096] In addition, in the above-described embodiment, the developer is a non-magnetic one-component developer composed only of toner, but a two-component developer using toner and a carrier may also be adopted.

[0097] The present invention can be applied to an image forming apparatus including a developing device that develops using a developer containing toner. By applying the present invention, it is possible to provide an image forming apparatus that can suppress the outflow of the developer.

Claims

1. A developing device, which comprises: a developing container having an opening and accommodating a developer containing toner therein; a developer carrier rotatably supported by the developing container, a part of the outer peripheral surface of the developer carrier for carrying the developer having a developing area exposed from the opening and facing an image carrier, and supplying the toner to the image carrier in the developing area; and a restricting blade disposed upstream of the developing area in the rotation direction of the developer carrier to restrict the layer thickness of the developer carried by the developer carrier, wherein the developing device is characterized in that the developing container has a blade facing portion facing the surface on the upstream side in the rotation direction of the restricting blade, the developing device includes a blade sealing member disposed between the restricting blade and the blade facing portion to block a gap between the restricting blade and the blade facing portion, the restricting blade has a fixing portion and a restricting portion, the fixing portion facing the blade facing portion and fixed to the developing container, the restricting portion protruding from the fixing portion toward the developer carrier, and the interval between the restricting portion and the blade facing portion being larger than the interval between the fixing portion and the blade facing portion, the blade sealing member is adhered to the surface on the upstream side in the rotation direction of the restricting portion.

2. The developing device according to claim 1, wherein the blade sealing member has: a first laminate laminated on a facing surface of the restricting blade facing the blade sealing member; and a second laminate laminated on a surface of the first laminate opposite to the restricting blade and having a rigidity greater than that of the first laminate.

3. The developing device according to claim 2, wherein the surface on the upstream side in the rotation direction of the second laminate is adhered to the blade facing portion.

4. The developing device according to claim 2 or 3, wherein both end portions of the second laminate in the rotation axis direction of the developer carrier are located more inward than both end portions of the first laminate in the rotation axis direction.

5. The developing device according to claim 2 or 3, wherein the first laminate has: a first sealing member and a second sealing member arranged in the rotation axis direction of the developer carrier; and a connecting portion formed at a facing portion between the first sealing member and the second sealing member, the connecting portion has: a first protruding portion protruding in the rotation axis direction from an end portion of the first sealing member on the second sealing member side toward the second sealing member; a first recessed portion recessed from the end portion of the first sealing member in a direction opposite to the protruding direction of the first protruding portion; a second protruding portion protruding in the rotation axis direction from an end portion of the second sealing member on the first sealing member side and inserted into the first recessed portion; and a second recessed portion recessed from the end portion of the second sealing member in a direction opposite to the protruding direction of the second protruding portion and for inserting the first protruding portion, An adhesive is coated on at least a part between the first protrusion and the second recess and between the first recess and the second protrusion to bond the first sealing member and the second sealing member, and the gap between the first sealing member and the second sealing member is blocked by the adhesive.

6. The developing device according to claim 2 or 3, characterized in that the first laminate is a sponge.

7. The developing device according to claim 2 or 3, characterized in that the second laminate is a sheet material formed of polyethylene terephthalate.

8. An image forming apparatus, characterized in that comprising: a device main body; an image carrier disposed inside the device main body and forming an electrostatic latent image on its outer peripheral surface; and the developing device according to any one of claims 1 to 7, detachably disposed inside the device main body, and in a state where the developing device is installed inside the device main body, the developer carrier contacts or approaches the outer peripheral surface of the image carrier to develop the electrostatic latent image into a toner image.

Images