Developing device and image forming apparatus including the same

Abstract

The present invention provides a developing device and an image forming apparatus including the developing device. The developing device includes a developing container, a developer carrier, and a restricting blade. The developing container has an opening. The developer carrier has a developing area. The developing container includes: a pair of side frames mounted at both end portions in the rotation axis direction of the developing container to support the developer carrier; and a pair of side wall portions located inside the pair of side frames with respect to the rotation axis direction, sandwiching the restricting blade and opposing each other in the rotation axis direction. At positions where the pair of side wall portions oppose end edges in the rotation axis direction of the restricting blade, seal member insertion holes penetrating in the rotation axis direction are formed. The developing device includes a blade-side side seal inserted into the seal member insertion holes to block a gap between the restricting blade and the side wall portions.

Description

Technical Field

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

[0002] Image forming apparatuses such as copiers, printers, facsimile machines, and digital multi-functional machines having these functions that use an electrophotographic method include a developing device that develops an electrostatic latent image formed on the outer peripheral surface of an image carrier, that is, forms a toner image (visible image) in which the electrostatic latent image appears.

[0003] The developing device includes: a developing container that houses a developer containing toner; and a developer carrier that is disposed in contact with or close to the image carrier and carries the developer. The developing container has a container opening that opens downstream of the developing container with respect to the moving direction inside the image forming apparatus when the developing device is mounted on the image forming apparatus. The developer carrier is disposed so as to coincide with the container opening. A part of the developer carrier is exposed to the outside of the developing device through the container opening. The developer carrier can carry the toner in the developing container on its outer peripheral surface. A developing area that faces the image carrier and supplies the toner in the developing container to the image carrier is formed on the exposed portion of the developer carrier that is exposed through the container opening.

[0004] As such a developing device, there is one in which a restricting blade is disposed upstream in the rotation direction of the developer carrier with respect to the developing area. The entire area of the restricting blade along the rotation axis of the developer carrier protrudes toward the outer peripheral surface of the developer carrier. The tip 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.

[0005] The developing container of such a developing device has a pair of side wall portions that sandwich the restricting blade therebetween with respect to the rotation axis direction. The inner surface of the side wall portion constitutes a side surface in the inner surface of the developing container with respect to the rotation axis direction. The end edge of the restricting blade in the rotation axis direction faces the side wall portion in the rotation axis direction. Summary of the Invention

[0006] An object of the present invention is to provide a developing device that can suppress an increase in manufacturing cost and can suppress the outflow of the developer, and an image forming apparatus including the developing device.

[0007] The present invention provides a developing device, which includes: a developing container having an opening and accommodating a developer containing toner therein; a developer carrier rotatably supported by the developing container, having a developing area where a part of the outer peripheral surface for carrying the developer is exposed from the opening and faces 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 rotational direction of the developer carrier to restrict the layer thickness of the developer carried by the developer carrier. The developing container has: a pair of side frames mounted at both ends in the rotational axis direction of the developer carrier of the developing container to support the developer carrier; and a pair of side wall portions located inside the pair of side frames with respect to the rotational axis direction, sandwiching the restricting blade and opposing each other in the rotational axis direction. At positions where the pair of side wall portions oppose the end edges of the restricting blade in the rotational axis direction, there are formed sealing member insertion holes penetrating in the rotational axis direction. The developing device further includes a side seal on the blade side, and the side seal on the blade side is inserted into the sealing member insertion hole to block the gap between the restricting blade and the side wall portion.

[0008] In addition, the present invention provides an image forming apparatus, which includes: a device main body; an image carrier provided inside the device main body and having an electrostatic latent image formed on its outer peripheral surface; and the developing device configured as described above, detachably provided inside the device main body. In a state where it 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.

[0009] In the developing device according to the present invention, at the positions where the pair of side wall portions oppose the restricting blade, there are formed sealing member insertion holes penetrating in the rotational axis direction. Therefore, even after the restricting blade is fixed to the developing container, the side seal on the blade side can be inserted into the sealing member insertion hole before the side frames are installed, so that the positioning of the side seal on the blade side can be easily performed. Thus, the installability of the developing device can be suppressed from deteriorating. Moreover, since the side seal on the blade side blocks the gap between the end edge of the restricting blade and the side wall portion, the outflow of the developer can be suppressed.

[0010] In addition, according to the present invention, an image forming apparatus can be provided that can suppress an increase in manufacturing cost and can suppress the outflow of the developer. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 FIG. 15 is a side cross-sectional view showing a schematic configuration of the image forming apparatus 1 of the present invention.

[0012] Figure 2 FIG. 19 is a perspective view showing the whole of the developing device 33.

[0013] Figure 3 is an enlarged cross-sectional view of a part around the photosensitive drum 31 and the developing device 33.

[0014] Figure 4 is a top view of the developing device 33 showing a state where the developing roller 37 and the side frame 63 are removed from the developing container 36.

[0015] Figure 5 is taken using Figure 4 the side sectional view of the developing device 33 cut along the line A - A shown.

[0016] Figure 6 is a perspective view showing the blade seal member 67.

[0017] Figure 7 is a partial enlarged view of the periphery of the end of the blade seal member 67 of the developing device 33 enlarged.

[0018] Figure 8 is taken using Figure 4 the partial enlarged sectional view of the cross-section of the developing device 33 cut along the line C - C shown enlarged.

[0019] Figure 9 is a perspective view of the developing device 33 showing a state where the side frame 63 is removed. Detailed Embodiments

[0020] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Figure 1 is a side sectional view showing a schematic configuration 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. In addition, 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.

[0021] As Figure 1 shown, the image forming apparatus 1 (here, a black and white printer) includes a main body casing 10 (apparatus main body), a paper feeding unit 20, an image forming unit 30, a developing device 33, and a fixing unit 40. The main body casing 10 has a box structure in a substantially rectangular parallelepiped shape. The paper feeding unit 20 is housed in the main body casing 10.

[0022] 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 side of the main body casing 10. The rear cover 12 is located on the rear 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, the inside of the main body casing 10 can be accessed through the main body opening 15.

[0023] On the upper surface of the upper cover 16, there is a paper discharge unit 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 unit 13 in the front-rear direction. The paper discharge port 14 is an opening leading to the inside of the casing 10. In addition, in the following description, the term "sheet body" means copy paper, coated paper, OHP film, thick paper, postcard, tracing paper, and other sheet body materials that undergo image formation processing.

[0024] The developing device 33 can enter and exit from the main body opening 15 in a state where the upper cover 16 is opened. Each unit (except the developing device 33) of the image forming unit 30 and the fixing unit 40 can enter and exit from the rear side of the main body casing 10 in a state where the rear cover 12 is opened.

[0025] The paper supply unit 20 includes a paper supply cassette 21. The paper supply cassette 21 houses the sheet body to be subjected to image formation processing. A part of the paper supply cassette 21 protrudes further forward than the front surface of the main body casing 10. The upper surface of the part of the paper supply cassette 21 housed inside the main body casing 10 is covered by the paper supply cassette top plate 21U.

[0026] In the paper supply cassette 21, there are a paper housing space for housing the stack of sheet bodies, a lifting plate for lifting the stack of sheet bodies for paper supply, etc. A paper extraction part 21A is provided at the upper part on the rear end side of the paper supply cassette 21. A paper supply roller 21B for extracting one by one the uppermost sheet body of the stack of sheet bodies in the paper supply cassette 21 is arranged at the paper extraction part 21A.

[0027] The image forming unit 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 unit 30 includes a photosensitive drum 31, a charging unit 32 arranged around the photosensitive drum 31, an exposure unit 35, a developing device 33, and a transfer roller 34. The developer used in image formation is a non-magnetic one-component developer composed only of toner.

[0028] The photosensitive drum 31 (image carrier) has a rotation axis and an outer peripheral surface that rotates around the rotation axis. A photosensitive layer is formed on the outer peripheral surface of the photosensitive drum 31. The photosensitive layer is constituted by a known organic (OPC) photoreceptor, for example, and is composed of a charge generation layer, a charge transport layer, and the like. After the photosensitive layer is uniformly charged by the charging unit 32 described later, it is irradiated with light by the exposure unit 35 to form an electrostatic latent image in which the charging is attenuated, and it bears a toner image in which the electrostatic latent image is developed by the developing device 33.

[0029] The charging unit 32 (charging device) is arranged at a prescribed interval with respect to 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 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 direction of the rotation axis 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 direction of the rotation axis of the photosensitive drum 31, and is arranged between the charging wire 321 and the photosensitive drum 31.

[0030] The charging unit 32 generates corona discharge by passing a current of a prescribed current value through the charging wire 321, and applies a prescribed voltage to the grid electrode 322, thereby uniformly charging the outer peripheral surface of the photosensitive drum 31 facing the grid electrode 322 with a prescribed surface potential.

[0031] The exposure unit 35 (exposure device) has a laser light source and optical system devices such as 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 given from an external device such as a personal computer. Thus, 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.

[0032] The transfer roller 34 has a rotation axis 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 casing 10 so as to be able to rotate around the rotation axis. 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. When performing this transfer, a transfer voltage having a polarity opposite to that of the toner is applied to the transfer roller 34.

[0033] The fixing unit 40 is located downstream of the transfer roller 34 in the sheet conveying 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 specified temperature. The pressure roller 42 is in pressure contact with the fixing roller 41, and forms a fixing nip portion therebetween. If the sheet with the transferred toner image passes through 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.

[0034] 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 for returning the sheet after single-sided printing to the upstream side of the image forming unit 30 of the main conveyance path 22F in the case of double-sided printing of the sheet.

[0035] The main conveyance path 22F extends so as to pass through the transfer nip portion formed by the photosensitive drum 31 and the transfer roller 34 from below upward. In addition, an alignment roller pair 23 is disposed upstream of the transfer nip portion in the main conveyance path 22F. The sheet temporarily stops at the alignment roller pair 23, and after the skew correction is performed, it is sent to the transfer nip portion at a specified timing for transferring the image. A plurality of conveyance rollers for conveying the sheet are disposed on the main conveyance path 22F and the reverse conveyance path 22B. A paper discharge roller pair 24 is disposed near the paper discharge port 14.

[0036] 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, one of the transfer roller 34 and the alignment roller pair 23 is provided on the inner side surface of the reverse unit 25. The rear cover 12 and the reverse unit 25 can be rotated respectively about the axes of the fulcrum portions 121 provided at their lower ends. When a jam (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.

[0037] As Figure 1 shown, guide rails 18 are formed on a pair of side surfaces 17 in the main body housing 10 opposite to the width direction of the sheet ( Figure 1 the paper surface direction). The guide rails 18 have an orbital structure recessed along the width direction of the sheet. The guide rails 18 extend downward from the main body opening 15 to the installation position P1 of the developing device 33 with respect to the main body housing 10.

[0038] Figure 2 It is a perspective view showing the whole developing device 33. Figure 3 It is an enlarged cross-sectional view of the periphery of the photosensitive drum 31 and the developing device 33 enlarged. Figure 4 It shows the developing roller 37 removed from the developing container 36 (refer to Figure 2 ) and the side frame 63 (refer to Figure 2 ), and it is a top view of the developing device 33 in the state.

[0039] As Figure 2 , Figure 3 , Figure 4 shown, 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.

[0040] The developing container 36 houses a non-magnetic one-component developer composed only of toner inside 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 side frame 63. The stirring chamber 335 houses the developer in a stirred state.

[0041] The container opening 60 is located on the rear side with respect to the front-rear direction compared to the stirring chamber 335. The container opening 60 is a rectangular through-hole that opens to the rear side (the side close to the photosensitive drum 31) of the developing container 36. The container opening 60 is formed to be elongated along the width direction (axial direction) of the developing device 33.

[0042] The developing roller 37 is disposed inside the container opening 60 so as to coincide with the container opening 60. A part of the outer peripheral surface of the developing roller 37 protrudes from the container opening 60 to the outside of the developing container 36. The developing roller 37 has a rotation shaft 39 that extends along the width direction (width direction of the thin plate body) 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 through the rotation shaft 39 so as to be able to rotate leftward as shown in the figure (refer to Figure 3 ). Hereinafter, the direction along the rotation shaft 39 will be referred to as the "axial direction (rotation shaft direction)". In addition, the rotation direction around the rotation shaft 39 of the developing roller 37 will be referred to as the "rotation direction".

[0043] The developing roller 37 can carry toner on its outer peripheral surface. When the developing device 33 is in the installation position P1, the part of the developing roller 37 that protrudes from the container opening 60 contacts and faces the outer peripheral surface of the photosensitive drum 31. In this state, the developing roller 37 can supply non-magnetic one-component toner (developer) to the photosensitive drum 31.

[0044] The supply roller 38 is disposed between the developing roller 37 and the stirring paddle 333, and supplies non-magnetic one-component toner (developer) to the outer peripheral surface of the developing roller 37. The stirring paddle 333 is disposed in the stirring chamber 335 and stirs the developer inside the stirring chamber 335.

[0045] As Figure 2 , Figure 3 shown, a flat portion 62, a front sealing member 65, a pressing member 43, a restricting blade 64, and a blade sealing member 67 are provided around the container opening 60. The flat portion 62 is located at a position rearward (closer to the photosensitive drum 31 side) than the container opening 60. The front sealing member 65 is placed on the flat portion 62. The pressing member 43 is provided at both axial ends of the developing roller 37. 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.

[0046] The flat portion 62 is a plane connected to a portion of the inner surface of the developing container 36 that is located below the developing roller 37. The flat portion 62 extends rearward (in the direction approaching the photosensitive drum 31) from the container opening 60. When the developing device 33 is in the installation position P1, the flat portion 62 is substantially horizontal.

[0047] The front sealing member 65 is a rectangular sheet formed of a PET film or the like. The front sealing member 65 is laminated on the flat portion 62 and adhered to the developing container 36 by an adhesive or the like. The front sealing member 65 is formed to be axially elongated. The front sealing member 65 extends along the axis across between the two end portions 66 of the developing roller 37.

[0048] The end edges of the front sealing member 65 in the front-rear direction (the direction orthogonal to the width direction of the sheet body) that are closer to the developing roller 37 (supply roller 38) side contact the entire area of the region on the outer peripheral surface of the developing roller 37 that bears the developer. 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, thereby suppressing the outflow of the developer in the developing container 36.

[0049] The front sealing member 65 has a first shielding portion 19. The first shielding portion 19 stands up in the surface direction of the front sealing member 65 from the end edges in the front-rear direction (the direction orthogonal to the width direction of the sheet body) that are away from the developing roller 37 (supply roller 38) side. 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-shaped and formed of sponge or the like. The first shielding portion 19 is adhered to the surface of the front sealing member 65 by an adhesive or the like. The first shielding portion 19 holds the developer so that the developer slightly flowing out from the gap between the developing roller 37 and the developing container 36 does not fall outside the developing device 33.

[0050] Outside the axial end portions of the first shielding portion 19, plate-shaped second shielding portions 53 that protrude upward are provided. The second shielding portions 53 are located at positions that coincide with the pressing member 43 in the axial direction. The second shielding portions 53 are integrally formed with a side frame 63 described later. In a state where the side frame 63 is attached to the developing container 36, the second shielding portions 53 extend in a manner approaching the first shielding portion 19 along the axial direction from the side frame 63.

[0051] Figure 5 is with Figure 4 The side sectional view of the developing device 33 cut along the line A-A shown. Figure 6 is a perspective view showing the blade sealing member 67. Figure 7 is the periphery of the end portion of the blade sealing member 67 of the developing device 33 ( Figure 4 The area surrounded by the double-dashed circle B) is an enlarged partial view. Figure 8 is with Figure 4 The sectional view of the developing device 33 cut along the line C-C shown is an enlarged partial sectional view. In addition, Figure 6 The blade sealing member 67 shown is a state where the blade sealing member 67 shown is reversed in the front-rear direction, Figure 4 and Figure 4 is Figure 6 opposite to the left-right direction of.

[0052] The pressing member 43 is located at positions that coincide with both end portions of the container opening 60 in the axial direction (refer to 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 toward the front side (the agitation 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.

[0053] The thickness of the pressing member 43 is larger 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 attached to 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 the both end portions 66 with the pressing surface 44, the gap between the both end portions 66 and the developing container 36 is blocked, and the outflow of the developer from the inside of the developing container 36 is suppressed.

[0054] The pressing member 43 has a multi-layer structure formed by laminating a plurality of sheets laminated in the radial direction of the developing roller 37 (here, a two-layer structure). At least the sheet closest to the developing roller 37 in the radial direction among the multi-layer sheets is a polytetrafluoroethylene sheet. The pressing surface 44 is formed on the surface of this sheet. The other sheets among the multi-layer sheets are formed of polyurethane foam such as sponge.

[0055] As Figure 3 , Figure 8 shown, a blade facing portion 45 is formed in the developing container 36. The blade facing portion 45 is a portion above the opening edge of the container opening 60. The blade facing portion 45 faces the upstream surface (the front surface in the front-rear direction) that restricts the rotation direction of the blade 64. The blade facing portion 45 is formed to be flat in the axial direction.

[0056] The restricting blade 64 is a rectangular plate-like body elongated in the axial direction (refer to Figure 2 ). The restricting blade 64 is composed of a fixing portion 46 and a restricting portion 47. The fixing portion 46 is a metal plate-like body that is L-shaped in a side view and has a bent portion bent at a substantially right angle. The fixing portion 46 is arranged to face the blade facing portion 45 in the rotation direction.

[0057] The restricting portion 47 is a rectangular plate-like body made of metal and elongated in the axial direction. The upper end portion of the restricting portion 47 is laminated and welded to the surface of the fixing portion 46 on the downstream side in the rotation direction (the side of the photosensitive drum 31). The restricting portion 47 protrudes from the lower end portion of the fixing portion 46 (the end portion of the fixing portion 46 closest to the developing roller 37 with respect to the up-down direction) toward the developing roller 37 (refer to Figure 3 ).

[0058] The front end portion in the protruding direction of the restricting portion 47 is arranged in contact with the outer peripheral surface of the developing roller 37. The toner supplied to the developing roller 37 enters between the restricting portion 47 and the developing roller 37 along with the rotation of the developing roller 37, is then triboelectrically charged, and is carried on the developing roller 37 as a thin layer of a certain thickness.

[0059] A through hole is formed at the laminated portion of the fixing portion 46 and the restricting portion 47 of the restricting blade 64, and the through hole penetrates the fixing portion 46 and the restricting portion 47 in the surface direction (thickness direction) of the fixing portion 46. The fixing portion 46 is fixed to the blade facing portion 45 by a fixing connection member 48 composed of a bolt or the like passing through the through hole (refer to Figure 8 ).

[0060] A blade seal member 67 is provided between the restricting blade 64 and the developing container 36 with respect to the rotation direction (a direction orthogonal to the axial direction). The blade seal member 67 is arranged between a pair of pressing members 43 with respect to the axial direction (refer to Figure 4)。The blade sealing member 67 is composed of multiple layers of sheets including a first laminated body 70 and a second laminated body 71 laminated in the front-rear direction.

[0061] As Figure 4 , Figure 5 , Figure 6 , Figure 7 shown, the first laminated body 70 is formed into a square shape from a sponge such as polyurethane foam. The first laminated body 70 is formed to be elongated in the axial direction. More specifically, the first laminated body 70 is formed by joining two sealing members (a first sealing member 72 and a second sealing member 73) arranged in the axial direction at the central portion in the axial direction with an adhesive or the like.

[0062] The first laminated body 70 is laminated on the surfaces of the fixing portion 46 and the restricting portion 47 that are away from the photosensitive drum 31 side (the surfaces upstream with respect to the rotation direction of the developing roller 37). On the surface of the first laminated body 70 on the downstream side in the rotation direction (the rear side in the front-rear direction), a double-sided tape having an adhesive component on both sides is pasted. In other words, a double-sided tape is disposed between the first laminated body 70 and the restricting portion 47. Through this double-sided tape, the first laminated body 70 is adhered to the restricting portion 47.

[0063] The second laminated body 71 is a sheet elongated in the axial direction. The second laminated body 71 is formed of polyethylene terephthalate (PET). The rigidity of the second laminated body 71 is greater than that of the first laminated body 70. As Figure 5 , Figure 6 shown, the second laminated body 71 is laminated on the surface of the first laminated body 70 on the side opposite to the contact surface with the restricting blade 64 (the surface away from the developing roller 37 side with respect to the front-rear direction). The second laminated body 71 is adhered to the first laminated body 70 with an adhesive or the like.

[0064] The axial length of the second laminated body 71 is shorter than the axial length of the blade sealing member 67. With respect to the axial direction, both end portions of the second laminated body 71 are located at positions closer to the inside than both end portions of the blade sealing member 67. In the region from both end portions in the axial direction of the blade sealing member 67 to both end portions of the second laminated body 71, a buffer portion 68 is formed.

[0065] The buffer portion 68 is a portion of the first laminated body 70 that protrudes from the second laminated body 71. The buffer portion 68 is in pressure contact with the pressing member 43 in the axial direction, blocking the gap between the blade sealing member 67 and the pressing member 43. The pressure contact portion of the buffer portion 68 with the pressing member 43 is located closer to the inside than the end edge of the restricting blade 64 with respect to the axial direction.

[0066] Figure 9 is a perspective view of the developing device 33 with the side frame 63 removed.

[0067] As shown Figure 9 in FIG. 4, a pair of side wall portions 50 that stand up upward from the bottom of the developing container 36 are provided at both axial end portions of the developing container 36. The side wall portions 50 face each other with the restriction blade 64 interposed therebetween in the axial direction. The developing roller 37 and the supply roller 38 penetrate the side wall portions 50 in the axial direction.

[0068] At positions where the pair of side wall portions 50 face the axial end edges of the restriction blade 64, seal member insertion holes 51 that penetrate in the axial direction are formed. The seal member insertion holes 51 are located at positions that coincide with the fixing portion 46 of the restriction blade 64 in the vertical direction. The seal member insertion holes 51 are located on the rear side with respect to the front-rear direction, more rearward than the restricting portion 47.

[0069] As shown Figure 9 in FIG. 5, side frames 63 are mounted on the outer sides in the axial direction of the side wall portions 50. The side frames 63 include a developing roller support hole 54, a supply roller support hole 55, and a positioning hole 56. The developing roller support hole 54, the supply roller support hole 55, and the positioning hole 56 are through holes that penetrate the side frames 63 in the axial direction.

[0070] The inner diameter of the developing roller support hole 54 is larger than the diameter of the rotating shaft 39 of the developing roller 37. The rotating shaft 39 is inserted into the developing roller support hole 54 and is rotatably supported by the side frame 63. The inner diameter of the supply roller support hole 55 is larger than the diameter of the rotating shaft 57 (refer to Figure 3 ) of the supply roller 38. The rotating shaft 57 is inserted into the supply roller support hole 55 and is rotatably supported by the side frame 63.

[0071] At the outer end portion in the axial direction of the developing container 36, a positioning projection 49 is provided. The positioning projection 49 projects outward in the axial direction from the developing container 36. The side frame 63 is positioned by inserting the positioning projection 49 into the positioning hole 56.

[0072] The guide portion 69 is a cylindrical projection that projects outward in the axial direction from the side wall portion 50 more than the side frame 63. The guide portion 69 can be engaged with the guide rail 18 (refer to Figure 1 ). By engaging the guide portion 69 with the guide rail 18, the developing device 33 can move between the main body opening portion 15 and the mounting position P1 along the guide rail 18 (refer to Figure 1 ).

[0073] 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 made visible is formed).

[0074] The blade-side side seal member 52 is inserted into the seal member insertion hole 51. The blade-side side seal member 52 is formed of an elastic material (preferably a sponge such as polyurethane foam). The blade-side side seal member 52 in the state before being disposed in front of the developing device 33 is square as shown in Figure 9 . The thickness of the blade-side side seal member 52 in the front-rear direction is larger than the dimension of the seal member insertion hole 51 in the front-rear direction. The dimension of the blade-side side seal member 52 in the left-right direction is larger than the axial interval between the side frame 63 and the end edge in the axial direction restricting the blade 64 after being mounted on the side wall portion 50.

[0075] As shown in Figure 9 , the outer surface in the axial direction of the side wall portion 50 of the developing container 36 in the state before mounting the side frame 63 is exposed to the outside. Therefore, in the state after fixing the restricting blade 64 to the developing container 36 and before mounting the side frame 63 to the developing container 36, the blade-side side seal member 52 can be inserted into the seal member insertion hole 51 from the outside in the axial direction of the side wall portion 50.

[0076] In the state where the blade-side side seal member 52 is inserted into the seal member insertion hole 51, if the side frame 63 is mounted on the side wall portion 50, the inner surface in the axial direction of the side frame 63 is in pressure contact with the blade-side side seal member 52. Therefore, the blade-side side seal member 52 is sandwiched and compressed between the side frame 63 and the end edge of the restricting blade 64 in the state of being located between the restricting blade 64 and the side wall portion 50. Thereby, a gap between the restricting blade and the side wall portion 50 can be prevented.

[0077] In addition, in this state, the blade-side side seal member 52 is located outside the axial direction of the pressure contact portion between the buffer portion 68 and the pressing member 43 (refer to Figure 7 ).

[0078] As described above, at the relative position of the pair of side wall portions 50 with respect to the restricting blade 64, a seal member insertion hole 51 penetrating in the axial direction is formed. Therefore, even after fixing the restricting blade 64 to the developing container 36, the blade-side side seal member 52 can be inserted into the seal member insertion hole 51 before mounting the side frame 63. Moreover, by mounting the side frame 63, the blade-side side seal member 52 can be appropriately disposed at the position between the end edge of the restricting blade 64 and the side wall portion 50. Therefore, the positioning of the blade-side side seal member 52 becomes easy, and thus the mountability of the developing device 33 can be suppressed from deteriorating. In addition, the blade-side side seal member 52 blocks the gap between the side frame 63 and the restricting blade 64. Thereby, the outflow of the developer can be suppressed.

[0079] Therefore, a developing device 33 that can suppress an increase in manufacturing cost and can suppress the outflow of the developer can be provided.

[0080] In addition, as described above, by mounting the side frame 63 to the developing container 36, the blade-side side seal 52 is clamped between the end edge restricting the axial direction of the blade 64 and the side frame 63. Thereby, the sealing performance of the blade-side side seal 52 can be improved without deteriorating the mountability. Therefore, an increase in manufacturing cost can be suppressed and outflow of the developer can be better suppressed.

[0081] In addition, as described above, the blade-side side seal 52 is formed of an elastic material, and thus is appropriately compressed in a state of being clamped between the blade 64 and the side frame 63. Thereby, the sealing performance of the blade-side side seal 52 can be improved.

[0082] In addition, as described above, the blade-side side seal 52 contacts the fixing portion 46 of the blade 64. The fixing portion 46 is thicker and has higher rigidity than the restricting portion 47. Therefore, the blade-side side seal 52 can be more appropriately compressed, thereby improving the sealing performance.

[0083] In addition, as described above, the second laminate 71 has higher rigidity than the first laminate 70. Therefore, the second laminate 71 serves as a support, and the first laminate 70 is less likely to bend. Therefore, when the first laminate 70 is bonded to the blade 64 (the fixing portion 46 and the restricting portion 47), generation of wrinkles and bending on the bonding surface where the first laminate 70 is bonded to the restricting portion 47 can be suppressed. Therefore, it is difficult to generate a gap between the first laminate 70 and the restricting portion 47, and thus outflow of the developer can be better suppressed.

[0084] In addition, as described above, buffer portions 68 are formed at both end portions of the first laminate 70. Therefore, when both end portions of the first laminate 70 contact the pressing member 43, the buffer portions 68 are compressed. Then, the compression rate of the portion (buffer portion 68) of the first laminate 70 that contacts the pressing member 43 becomes high, and the sealing performance between the first laminate 70 and the pressing member 43 can be improved. Therefore, outflow of the developer can be better suppressed.

[0085] In addition, as described above, the blade-side side seal 52 is located axially outside the pressure contact portion between the buffer portion 68 and the pressing member 43. Therefore, even if a gap is generated between the buffer portion 68 and the pressing member 43, and the developer flows into the back surface of the blade 64 through the gap and enters the opposing portion between the end edge of the blade 64 and the side wall portion 50, the blade-side side seal 52 can block the developer. Therefore, outflow of the developer through between the blade 64 and the side wall portion 50 can be suppressed.

[0086] In addition, a first shielding portion 19 protruding upward is provided over the entire area of the end edge in the longitudinal 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 facing downward, the waste toner around the container opening 60 is blocked by the first shielding portion 19. Therefore, it is possible to suppress the waste toner from falling into the main body casing 10.

[0087] In addition, as described above, the second shielding portion 53 is located at a position overlapping the pressing member 43 with respect to the axis. Therefore, even if it is assumed that the developer slightly flows out from the gap between the pressing member 43 and the developing roller 37, it is possible to prevent the outflow to the outside of the developing container 36 by the second shielding portion 53. In addition, as described above, the second shielding portion 53 is integrally formed with the side frame 63. Therefore, at the same time as the side frame 63 is installed, the second shielding portion 53 is also positioned at a predetermined position. Therefore, it is possible to reduce the number of installation man-hours, and thus suppress the manufacturing cost.

[0088] 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, as an example of the image forming apparatus 1, a monochrome printer has been described, but the present invention can also be applied to, for example, tandem type or rotary color printers. In addition, the present invention can also be applied to image forming apparatuses such as copiers, facsimile machines, or digital multi-function machines having these functions.

[0089] In addition, when the restriction blade 64 and the developing roller 37 can be replaced for reasons such as maintenance, the side frame 63 can also be detachably attached to the developing container 36. In this case, for example, the side frame 63 can have a structure having a plurality of engaging portions protruding along the axis and formed with claws at the front ends in the protruding direction. The side frame 63 can be attached to the developing container 36 by an insertion fitting structure in which the engaging portions are engaged with a plurality of notch portions formed in the developing container 36 by using the above-described claws.

[0090] In addition, the blade side side seal 52 is clamped between the developing container 36 and the side wall portion 50 by the installation of the side frame 63, but it is not limited thereto. For example, a structure in which the blade side side seal 52 is adhered to the restriction blade 64 can also be adopted.

[0091] 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 can also be adopted.

[0092] The present invention can be applied to an image forming apparatus including a developing device that develops using a developer containing toner. By using the present invention, an image forming apparatus can be provided that can suppress an increase in manufacturing cost and can suppress the outflow of the developer.

Claims

1. A developing device, characterized in that, comprising: a developing container having an opening and accommodating a developer containing toner therein; a developer carrier rotatably supported by the developing container, having a developing area where a part of the outer peripheral surface for carrying the developer is exposed from the opening and faces the 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 rotational direction of the developer carrier to restrict the layer thickness of the developer carried by the developer carrier, the developing container having: a pair of side frames mounted at both ends in the rotational axis direction of the developer carrier of the developing container to support the developer carrier; and a pair of side wall portions located inside the pair of side frames with respect to the rotational axis direction, sandwiching the restricting blade and opposing each other in the rotational axis direction, a sealing member insertion hole penetrating in the rotational axis direction is formed at a position where the pair of side wall portions oppose the end edge in the rotational axis direction of the restricting blade, the developing device further includes a side-to-side seal for the blade, and the side-to-side seal for the blade is inserted into the sealing member insertion hole to block the gap between the restricting blade and the side wall portion.

2. The developing device according to claim 1, characterized in that, the side-to-side seal for the blade is formed of an elastic material, and by mounting the side frame to the developing container, the side-to-side seal for the blade is clamped between the end edge in the rotational axis direction of the restricting blade and the side frame.

3. The developing device according to claim 2, characterized in that, the side-to-side seal for the blade is a sponge.

4. The developing device according to any one of claims 1 to 3, characterized in that, the restricting blade has: a fixing portion fixed to the developing container; and a restricting portion protruding from the fixing portion toward the developer carrier, the side-to-side seal for the blade contacts the fixing portion to block the gap between the fixing portion and the side wall portion.

5. The developing device according to claim 1, characterized in that, the developer is a non-magnetic one-component developer composed only of non-magnetic toner.

6. An image forming device, characterized in that, comprising: a device main body; an image carrier disposed inside the device main body and having an electrostatic latent image formed on its outer peripheral surface; and the developing device according to any one of claims 1 to 5, detachably disposed inside the device main body, and in a state of being mounted 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