Developing device

Abstract

To optimize an amount of a mixture of a lubricant and a toner generated on a projection part, to improve fluidity of the toner in the vicinity of a cutout part and suppress leakage of the toner.SOLUTION: A development device comprises a surface layer 210 in contact with the peripheral surface of a development roller, and a side seal 200 having a base layer 220 arranged between the surface layer 210 and a housing 50. The base layer 220 has a projection part 222 protruding axially inward with respect to a side edge seal 140, and located within a cutout part 121 of a blade rubber part 120. The surface layer 210 has a fiber layer 211, and a first fiber region 213 in which an axially inward edge protrudes axially inward with respect to the axially inward edge of a base sheet 212, and overlaps the projection part 222 when viewed from a direction from the surface layer 210 to the base layer 220. A downstream edge is located at the same position in a rotational direction as an upstream edge of the side edge seal 140 or on the upstream side with respect to the upstream edge of the side edge seal 140.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a developing device having a side seal that comes into contact with an end portion of a developing roller in the axial direction. [Background technology]

[0002] Conventionally, a developing device is known that includes a housing that contains toner, a developing roller rotatably held in the housing, a layer thickness regulating blade that contacts the developing roller, and a side seal that is disposed between the housing and an end of the developing roller (see, for example, Patent Document 1). In this developing device, the layer thickness regulating blade has a blade body made of sheet metal and a blade rubber portion that protrudes from the blade body and contacts the developing roller. A concave cutout portion is formed in the blade rubber portion.

[0003] The side seal is disposed between the end of the blade body and the housing. The side seal has a surface layer that contacts the peripheral surface of the developing roller, and a base layer that is disposed between the surface layer and the housing. The surface layer has a fiber layer made of a plurality of fibers that contacts the peripheral surface of the developing roller, and a base sheet in which the fiber layer is implanted. The base layer has a protruding portion that protrudes inward in the axial direction of the developing roller beyond the surface layer. The protruding portion is disposed upstream of the notch in the blade rubber portion in the rotational direction of the developing roller. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-060033 A Summary of the Invention [Problem to be solved by the invention]

[0005] The applicant of the present application has devised a technique in which a lubricant is applied to the surface layer, and the lubricant applied to the surface layer is moved along each fiber onto the protruding portion on the inside in the axial direction by rotating the developing roller. In this technique, the lubricant and toner are mixed on the protruding portion, and a mixture is generated on the protruding portion, which makes it possible to suppress toner leakage.

[0006] In this technique, the greater the amount of lubricant present on the protrusion, the larger the size of the mixture tends to be. However, if the size of the mixture is too large, the toner may not flow well around the notch. Conversely, if the size of the mixture is too small, the mixture may not be able to effectively prevent toner leakage. Therefore, in this technique, it is necessary to appropriately adjust the overlapping amount between each fiber that transfers the lubricant to the protrusion and the protrusion.

[0007] Therefore, the present invention aims to achieve both improved toner fluidity near the cutout and suppression of toner leakage by adjusting the amount of the mixture of lubricant and toner generated on the protrusion to an appropriate amount. [Means for solving the problem]

[0008] In order to achieve the above object, a developing device according to the present invention includes a housing, a rotatable developing roller, a layer thickness regulating blade having a blade rubber portion that contacts the peripheral surface of the developing roller and has a notch at an end in an axial direction of the developing roller, and a blade main body that supports the blade rubber portion, a side seal that is arranged between the housing and the developing roller so as to contact the peripheral surface of the developing roller at an end in the axial direction of the developing roller, the side seal having a surface layer that contacts the peripheral surface of the developing roller and a base layer that is arranged between the surface layer and the housing, and a side edge seal that is arranged so as to contact the end in the axial direction of the blade rubber portion, and an upstream edge in a rotation direction of the developing roller overlaps with the side seal, and the base layer is disposed between the side edge and the base layer. The developing roller has a protruding portion that protrudes axially inward more than the seal and has a portion that is located within the range of the notch in the axial direction, and the surface layer is a fiber layer consisting of a plurality of fibers that contact the developing roller, and includes a fiber layer to which a lubricant is applied and a base sheet in which the plurality of fibers in the fiber layer are implanted, and the fiber layer has a first fiber region whose axially inner edge protrudes axially inward more than the axially inner edge of the base sheet and overlaps with the protruding portion when viewed from the direction from the surface layer to the base layer, and the downstream edge of the first fiber region in the rotational direction is located at the same position in the rotational direction as the upstream edge of the side edge seal in the rotational direction or upstream of the upstream edge of the side edge seal in the rotational direction.

[0009] According to this configuration, the fibers of the first fiber region supply the lubricant onto the protruding portion and hold the mixture of toner and lubricant produced upstream of the upstream edge of the side edge seal in the direction of rotation, forming a wall of the mixture. Then, near the notch, specifically downstream of the upstream edge of the side edge seal in the direction of rotation, the fibers of the first fiber region do not supply an excessive amount of lubricant onto the protruding portion and do not hold the mixture of toner and lubricant produced. This makes it possible to make the amount of mixture near the notch appropriate, thereby improving the fluidity of the toner and suppressing toner leakage at the same time. Effect of the Invention

[0010] According to the present invention, the amount of the mixture of lubricant and toner generated on the protrusion can be adjusted to an appropriate amount, thereby improving the fluidity of the toner near the cutout while suppressing toner leakage. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a cross-sectional view showing a developing device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an exploded perspective view of the developing device; [Diagram 3] FIG. 4 is an exploded perspective view of the side seal. [Figure 4] 1A is a plan view showing a surface layer, FIG. 1B is a cross-sectional view showing a structure in the vicinity of a side seal, and FIG. 1C is a plan view showing a first fiber region and a second fiber region. [Diagram 5] 13(a) to 13(c) are diagrams showing a simplified relationship between a side seal and the surrounding components during the process of assembling each component to a housing. [Figure 6] 1A is a front view of the housing from the opening side before the supply roller and other components are attached, and FIG. [Figure 7] 1A is a front view and FIG. 1B is a perspective view showing a state in which a side seal is attached to a housing. [Figure 8] 1A is a front view and FIG. 1B is a perspective view showing the state in which the blade back seal is attached to the housing. [Figure 9] 1 is a front view showing a state in which a layer thickness regulating blade and the like are assembled to a housing. [Figure 10] 10 is a diagram showing a simplified relationship between a side seal, a lower film, and surrounding members. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A developing device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. 1, the developing device 28 is used in an image forming apparatus such as a printer. The developing device 28 includes a rotatable developing roller 31, a layer thickness regulating blade 100, a rotatable supply roller 33, a toner storage chamber 34, and a rotatable agitator 34A. The supply roller 33 is in contact with the developing roller 31.

[0013] In this developing device 28, the toner contained in the toner storage chamber 34 is agitated by an agitator 34A, and then supplied to the developing roller 31 by the supply roller 33. At this time, the toner is positively triboelectrically charged between the supply roller 33 and the developing roller 31. The toner supplied onto the developing roller 31 enters between the layer thickness regulating blade 100 and the developing roller 31 as the developing roller 31 rotates. As a result, the toner is further triboelectrically charged between the layer thickness regulating blade 100 and the developing roller 31. In addition, the toner on the developing roller 31 is regulated by the layer thickness regulating blade 100 to a thin layer of a constant thickness.

[0014] The toner in this embodiment is a positively charged non-magnetic one-component toner, and is made by adding a well-known colorant such as carbon black and a charge control agent such as a quaternary ammonium salt to a styrene-acrylic resin formed into a spherical shape by suspension polymerization. The toner base particles have an average particle size of 4 μm to 10 μm, and silica is added to the surface as an external additive. The toner is not limited to the above-mentioned types of toner, and may be, for example, a negatively charged toner.

[0015] Next, the detailed structure of the developing device 28 will be described. In addition, since the developing device 28 has a structure that is approximately symmetrical in the axial direction of the developing roller 31, in the figures referred to below, only the portion at one end in the axial direction of the developing roller 31 will be shown, and the portion at the other end will be omitted.

[0016] 2, the developing device 28 includes the developing roller 31 and the like as described above, as well as a housing 50 for accommodating toner, a side seal 200 that contacts an end of the developing roller 31 in the axial direction, and a blade back seal 36 that is disposed between the layer thickness regulating blade 100 and the housing 50. In this embodiment, the developing roller 31 is provided so as to rotate in the direction of the arrow shown in FIG. 2, that is, in the direction in which the circumferential surface of the developing roller 31 rubs against the surface of the side seal 200 from the side farther from the layer thickness regulating blade 100 to the side closer to the layer thickness regulating blade 100. In the following description, the rotation direction of the developing roller 31 is also simply referred to as the "rotation direction."

[0017] The developing roller 31 has a cylindrical roller portion 31A and a shaft portion 31B that supports the roller portion 31A. The roller portion 31A has elasticity. The roller portion 31A carries toner on its peripheral surface. The shaft portion 31B penetrates the roller portion 31A. The shaft portion 31B protrudes outward in the axial direction of the developing roller 31 beyond the roller portion 31A.

[0018] The housing 50 has a bearing portion 51 that rotatably supports the shaft portion 31B of the developing roller 31, an opening 52 for supplying toner from the internal toner storage chamber 34 to the developing roller 31, an arrangement surface 53 on which the side seal 200 is arranged, and a protrusion 54 that regulates the position of a protruding portion 222 (described later) of the side seal 200. The bearing portion 51 is formed on a side wall 56 of the housing 50.

[0019] The opening 52 is a rectangular hole that is long in the axial direction. The blade back seal 36 and the layer thickness regulating blade 100 are disposed on one end side of the opening 52 in the short side direction, specifically on the upper side in the figure. Also, the supply roller 33 is disposed within the opening 52. The supply roller 33 is disposed on the other end side of the opening 52 in the short side direction, specifically on the lower side in the figure.

[0020] In the following description, the short-side direction of the opening 52 corresponds to the up-down direction in the drawing, and therefore the short-side direction is also referred to as the "up-down direction". One end side in the short-side direction is also referred to as the "upper side", and the other end side in the short-side direction is also referred to as the "lower side". The axial direction of the developing roller 31 corresponds to the left-right direction in the drawing, and therefore the axial direction is also referred to as the "left-right direction". One end side in the axial direction is also referred to as the "left side", and the other end side in the axial direction is also referred to as the "right side". Furthermore, the orthogonal direction perpendicular to the short-side direction and the axial direction is also referred to as the "front-rear direction". One end side in the front-rear direction, specifically the side where the developing roller 31 is disposed with respect to the opening 52, is also referred to as the "front side", and the other end side in the front-rear direction, specifically the side where the agitator 34A is disposed with respect to the opening 52, is also referred to as the "rear side".

[0021] The blade back seal 36 is made of an elastic member such as a sponge. The blade back seal 36 is an elongated member that is long in the left-right direction. The blade back seal 36 is larger than the opening 52 in the left-right direction. The blade back seal 36 has a rectangular base portion 36A that extends from near the left end of the opening 52 to near the right end. A plurality of recesses 36B recessed downward are formed at the upper end of the base portion 36A.

[0022] A first portion 36C is provided on each end surface of the base portion 36A in the left-right direction, protruding outward in the left-right direction from each end surface. The first portion 36C has a smaller width in the up-down direction than the base portion 36A. The first portion 36C is disposed at a position biased downward with respect to the base portion 36A.

[0023] The second portion 36D is provided on an outer end surface of the first portion 36C in the left-right direction, protruding outward in the left-right direction from the end surface. The second portion 36D has a smaller vertical width than the first portion 36C. The second portion 36D is disposed at a position biased downward with respect to the first portion 36C. The second portion 36D constitutes an end portion of the blade back seal 36 in the left-right direction. The second portion 36D is located axially outward of the opening 52 (see FIG. 8(a)).

[0024] The blade back seal 36 is fixed to the housing 50 (more specifically, the portion above the opening 52) with double-sided tape TP. The double-sided tape TP is provided on the base portion 36A and the first portion 36C of the blade back seal 36. The double-sided tape TP is not provided on the second portion 36D. As a result, the second portion 36D is not fixed to the housing 50 by the double-sided tape TP, and is free to deform.

[0025] The layer thickness regulating blade 100 has a blade body 110 extending in the left-right direction, a rubber blade rubber part 120 fixed to the lower end (tip) of the blade body 110, and a blade holder 130 supporting the upper end of the blade body 110.

[0026] The blade body 110 is a generally rectangular metal plate that is long in the left-right direction. An upper end of the blade body 110 is fixed to the housing 50 via a blade holder 130. A lower end of the blade body 110 is a free end.

[0027] The blade rubber part 120 is a rubber member that extends in the left-right direction and is smaller in size in the left-right direction than the blade body 110. The blade rubber part 120 is formed of, for example, silicone rubber or urethane rubber. The blade rubber part 120 is provided at the lower end of the blade body 110. The blade rubber part 120 protrudes from the surface of the blade body 110 that faces the developing roller 31 and contacts the circumferential surface of the roller part 31A of the developing roller 31. The surface 120A of the blade rubber part 120 that contacts the developing roller 31 is flat, and the corners on the upstream and downstream sides in the rotation direction are arc-shaped in cross section (see FIG. 1).

[0028] The blade rubber part 120 has a notch 121 at each end in the left and right direction. The notch 121 is a cutout portion on the upstream side in the rotation direction at each end in the left and right direction of the blade rubber part 120.

[0029] The cutout portion 121 has a first surface 123 extending inward in the left-right direction from the lower edge of the end surface 122, and a second surface 124 extending downward from the first surface 123. The first surface 123 is aligned in the left-right direction.

[0030] By providing such a notch 121 in the blade rubber part 120, the corner between the surface 120A of the blade rubber part 120 that contacts the developing roller 31 and the first surface 123 is approximately at a right angle. Also, the corner between the surface 120A of the blade rubber part 120 that contacts the developing roller 31 and the second surface 124 is approximately at a right angle. In other words, the blade rubber part 120 has an edge part 123A (a tip part of a corner sharpened at an approximately right angle) at each end in the left and right direction that contacts the peripheral surface of the roller part 31A of the developing roller 31. The edge part 123A is formed to extend in the left and right direction. In this manner, the sharp edge part 123A is easier to scrape off the toner on the developing roller 31 than a part shifted inward in the left and right direction from the edge part 123A of the blade rubber part 120.

[0031] The lower edge of the blade body 110 is formed in a shape corresponding to the blade rubber part 120. Furthermore, each left and right end of the blade body 110 extends outward beyond the blade rubber part 120 in the left and right direction.

[0032] A rectangular side edge seal 140 is provided at each end of the blade body 110 in the left and right direction. The side edge seal 140 is made of, for example, nonwoven fabric or sponge material. The side edge seal 140 is attached to the front surface of the blade body 110 (the surface facing the developing roller 31). The side edge seal 140 is in contact with the end surface 122 in the left and right direction of the blade rubber part 120. The side edge seal 140 extends downward from a position adjacent to the end surface 122. The side edge seal 140 extends downward beyond the blade body 110. The lower edge of the side edge seal 140 is in contact with a side seal 200 described later. This prevents toner from leaking from both the left and right ends of the blade rubber part 120 to the outside of the developing device 28. (See FIG. 5(c)).

[0033] The side seals 200 are seals that come into contact with the left and right ends of the developing roller 31, more specifically, the peripheral surfaces of the left and right ends of the roller portion 31A. The side seals 200 are disposed between the arrangement surface 53 and the roller portion 31A.

[0034] Here, the arrangement surfaces 53 are arranged on both left and right sides of the opening 52. As shown in Fig. 6(b) , a protrusion 54 is provided on an inner end portion in the left and right direction of the arrangement surface 53. The protrusion 54 protrudes from the arrangement surface 53 toward the developing roller 31 side.

[0035] A wall portion 55 is provided on the downstream side of the protrusion 54 in the rotational direction, protruding from the arrangement surface 53 toward the developing roller 31. The wall portion 55 is located outward in the left-right direction from the protrusion 54. The height of the protrusion 54 and the wall portion 55 from the arrangement surface 53 is smaller than the thickness of the base layer 220 of the side seal 200.

[0036] Further, a recess 53A is formed in the arrangement surface 53. As shown in Fig. 2, a supply roller seal 60 is provided in the recess 53A so as to cover a bearing (not shown) of the supply roller 33. The supply roller seal 60 and the arrangement surface 53 support the side seal 200 from the side opposite to the developing roller 31.

[0037] As shown in Fig. 3, the side seal 200 has a surface layer 210, a base layer 220, and an adhesive layer 230 that bonds the surface layer 210 to the base layer 220. The surface layer 210 is a layer that contacts the peripheral surface of the roller portion 31A of the developing roller 31. The surface layer 210 has a fiber layer 211 made of a plurality of fibers FB (see Fig. 4) that contacts the roller portion 31A of the developing roller 31, and a base sheet 212 in which the fibers FB are implanted. In detail, the surface layer 210 is a pile fabric, and is formed by cutting loop-shaped pile so that the fiber FB (cut pile) protrudes from the base sheet 212 as a foundation.

[0038] The base sheet 212 is made of, for example, cloth. The base sheet 212 has a rectangular first sheet portion 212A extending along the rotation direction of the developing roller 31, and a second sheet portion 212B extending from the first sheet portion 212A toward the upstream side in the rotation direction. The second sheet portion 212B has a smaller width in the left-right direction than the first sheet portion 212A. The second sheet portion 212B has a smaller length in the rotation direction than the first sheet portion 212A. The second sheet portion 212B is disposed so as to be biased inward in the left-right direction with respect to the first sheet portion 212A (see FIG. 5(a)).

[0039] The adhesive layer 230 is made of an adhesive applied to the surface of the base sheet 212 facing the base layer 220. The adhesive layer 230 is formed on a part of the surface of the base sheet 212 facing the base layer 220, more specifically, on a portion of the surface on the downstream side in the direction of rotation. In other words, the portion of the base sheet 212 on the downstream side in the direction of rotation is adhered to the base layer 220, and the portion of the base sheet 212 on the upstream side in the direction of rotation is not adhered to the base layer 220. The adhesive layer 230 has a rectangular shape in a plan view. The adhesive layer 230 may be made of, for example, double-sided tape.

[0040] The base layer 220 is made of an elastic body such as urethane sponge. The base layer 220 is disposed between the surface layer 210 and the housing 50. The base layer 220 has a base portion 221 that mainly has an area AR where the adhesive layer 230 is provided, and a protruding portion 222 that protrudes inward in the left-right direction from the base portion 221. The base portion 221 has a first base portion 221A that is rectangular and long in the rotation direction, a second base portion 221B that protrudes from the first base portion 221A toward the upstream side in the rotation direction, a third base portion 221C that protrudes from the first base portion 221A toward the downstream side in the rotation direction, and a fourth base portion 221D that protrudes from the third base portion 221C toward the downstream side in the rotation direction.

[0041] The first base portion 221A has a first width in the left-right direction. The second base portion 221B has a second width in the left-right direction that is smaller than the first width. The second base portion 221B is disposed offset inward in the left-right direction with respect to the first base portion 221A.

[0042] The third base portion 221C has a third width in the left-right direction that is smaller than the first width and larger than the second width. The third base portion 221C is disposed biased toward the inside in the left-right direction with respect to the first base portion 221A. The fourth base portion 221D has a fourth width in the left-right direction that is smaller than the second width. The fourth base portion 221D is disposed approximately in the center of the third base portion 221C in the left-right direction.

[0043] The protruding portion 222 protrudes inward in the left-right direction from the region AR to which the adhesive layer 230 is adhered, that is, from the adhesive layer 230. In other words, the protruding portion 222 protrudes inward in the left-right direction from the base sheet 212 (see FIG. 4(b)). The protruding portion 222 has a first protruding portion 222A that protrudes from the region AR by a first protruding amount, and a second protruding portion 222B that protrudes from the region AR by a second protruding amount that is smaller than the first protruding amount. The second protruding portion 222B is adjacent to the first protruding portion 222A on the upstream side in the rotational direction. The second protruding portion 222B has a length in the rotational direction shorter than that of the first protruding portion 222A.

[0044] 4(a) and (b), the base ends of the fibers FB are fixed to the surface of the base sheet 212 opposite to the adhesive layer 230. Each fiber FB is inclined with respect to the base sheet 212 so that its tip faces the downstream side in the rotation direction and the inner side in the left-right direction. In other words, each fiber FB is inclined with respect to the rotation direction so that it is positioned inward in the left-right direction as it moves toward the downstream side in the rotation direction.

[0045] As shown in FIG. 4( c ), the fiber layer 211 has a first fiber region 213 and a second fiber region 214 . An inner edge 213A of the first fiber region 213, more specifically, a tip of the fiber FB located most inner in the first fiber region 213, protrudes inward in the left-right direction from an inner edge 212E of the base sheet 212. The inner edge 213A of the first fiber region 213 overlaps with a protruding portion 222 when viewed from the surface layer 210 toward the base layer 220. More specifically, the base sheet 212 and the adhesive layer 230 are not present between the inner edge 213A of the first fiber region 213 and the protruding portion 222 when viewed from the surface layer 210 toward the base layer 220.

[0046] The inner end of the fiber FB of the first fiber region 213 protrudes inward in the left-right direction beyond the inner edge of the base sheet 212. The inner end of the fiber FB of the first fiber region 213 overlaps the protruding portion 222 when viewed from the direction from the surface layer 210 toward the base layer 220 (see FIG. 5(a)).

[0047] Specifically, the inner edge 213A of the first fiber region 213 is located laterally outward from the innermost surface of the protruding portion 222, that is, the inner surface 222C of the first protruding portion 222A. The inner edge 213A of the first fiber region 213 is located laterally inward from the center of the protruding portion 222. Here, in FIG. 4(b), for convenience, the center of the protruding portion 222 in the left-right direction is indicated by a dashed line.

[0048] The downstream edge 213B of the first fiber region 213 in the rotational direction, more specifically, the tip of the fiber FB located most downstream in the first fiber region 213 in the rotational direction, coincides with the upstream edge 140A of the side edge seal 140 in the rotational direction. The upstream edge 213C of the first fiber region 213 in the rotational direction, more specifically, the base end of the fiber FB located most upstream in the rotational direction in the first fiber region 213, coincides with the upstream edge 212C of the base sheet 212 in the rotational direction.

[0049] The second fiber region 214 does not protrude from an inner edge 212E of the base sheet 212 in the left-right direction, and an inner edge 214A in the left-right direction coincides with the inner edge 212E of the base sheet 212 in the left-right direction.

[0050] The downstream edge 214B of the second fiber region 214, more specifically, the most downstream tip of the fiber FB in the second fiber region 214, is located downstream in the rotational direction from the downstream edge 213B of the first fiber region 213. The downstream edge 214B of the second fiber region 214 coincides with the downstream edge 212D of the base sheet 212 in the rotational direction.

[0051] The length of each fiber FB, specifically, the length from the base sheet 212 to the tip of the fiber FB, can be, for example, 1.0 mm or more and 2.0 mm or less. In addition, a lubricant is applied to the multiple fibers FB.

[0052] The lubricant may be applied to at least a part of the outer side of the plurality of fibers FB in the left-right direction during the manufacturing of the developing device 28. In this case, the lubricant is spread over the entire surface of the side seal 200 by rotating the developing roller 31 after the manufacturing is completed. More specifically, the lubricant moves along the plurality of fibers FB to the inner side in the left-right direction and downstream in the rotation direction as the developing roller 31 rotates, and is spread to the protruding portion 222. The lubricant may be applied to the entire surface of the fiber layer 211 during the manufacturing of the developing device 28. The lubricant is not applied to the side edge seal 140.

[0053] The lubricant may be, for example, a fluorine-based resin and a fluorine oil dispersed in a solvent. Alternatively, a lubricant containing fluorine, such as silicone grease or heat-resistant fluorine grease, may be used.

[0054] Further, the outer surface in the left-right direction of the base layer 220 (more specifically, the outer surface in the left-right direction of the first base portion 221A) is in contact with the side wall 56 of the housing 50.

[0055] 5(a) to 5(c) are diagrams showing the relationship between the side seal 200 and the surrounding components during the process of assembling the components to the housing 50. For convenience, in Figs. 5(a) to 5(c), the side seal 200 is shown in a state where it is stretched straight along the circumferential surface of the developing roller 31 without being bent.

[0056] 5(a) is a simplified diagram showing the state in which the side seal 200 and the blade back seal 36 are assembled to the housing 50 (not shown). In this state, the fourth base portion 221D of the base layer 220 of the side seal 200 is in contact with the second portion 36D, which is the end portion of the blade back seal 36. More specifically, the inner surface in the left-right direction of the fourth base portion 221D is in contact with the second portion 36D.

[0057] In this state, the protrusion 54 is in contact with the inner surface of the protruding portion 222 in the left-right direction. More specifically, the protrusion 54 is located closer to the downstream edge of the protruding portion 222 in the rotational direction than to the upstream edge of the protruding portion 222 in the rotational direction. In other words, the distance from the protrusion 54 to the downstream edge of the protruding portion 222 in the rotational direction is smaller than the distance from the protrusion 54 to the upstream edge of the protruding portion 222 in the rotational direction. More specifically, the protrusion 54 is in contact with the downstream end of the first protruding portion 222A in the rotational direction.

[0058] In this state, the wall portion 55 is separated in the left-right direction from the base portion 221. Furthermore, the wall portion 55 is in contact with the surface of the protruding portion 222 on the downstream side in the rotational direction. As a result, the position of the protruding portion 222 in the rotational direction is regulated by the wall portion 55.

[0059] As shown in FIGS. 7(a) and 7(b), when the supply roller 33 is attached to the housing 50, the protrusion 54 is located between the protruding portion 222 and the roller portion of the supply roller 33 in the left-right direction.

[0060] 5(b) is a simplified diagram showing a state in which the layer thickness regulating blade 100 is assembled to the housing 50 from the front side of the side seal 200 and the blade back seal 36. In this state, the base sheet 212 is located outboard in the left-right direction from the blade rubber part 120. Here, "located outboard in the left-right direction from the blade rubber part 120" also includes a case in which the inner left-right edge of the base sheet 212 and the left-right end face 122 of the blade rubber part 120 are in the same position in the left-right direction, as shown in FIG.

[0061] In this state, the protruding portion 222 has a portion located upstream of the edge portion 123A in the rotational direction and within the range of the edge portion 123A in the left-right direction. More specifically, the protruding portion 222 is located outside in the left-right direction from the inner end of the edge portion 123A in the left-right direction.

[0062] Further, the end face of the protruding portion 222 on the downstream side in the rotational direction is disposed in a position in the rotational direction close to the cutout portion 121. In detail, the distance in the rotational direction between the edge portion 123A of the cutout portion 121 and the protruding portion 222 can be, for example, 1.5 mm or more and 3.5 mm or less.

[0063] In the state shown in Fig. 5(b), the inner edge 213A of the first fiber region 213 is located laterally outward of the inner end of the edge portion 123A. In the state shown in Fig. 5(b), the wall portion 55 is disposed on the rear side (back side) of the layer thickness regulating blade 100. The wall portion 55 is disposed at a distance from the layer thickness regulating blade 100 in the front-rear direction.

[0064] Wall portion 55 is provided within the range of cutout portion 121 in the left-right direction. A part of wall portion 55 is provided within the range of cutout portion 121 in the rotational direction. An inner end portion of wall portion 55 in the left-right direction is disposed outer in the left-right direction than second surface 124, which is an inner end portion of cutout portion 121 in the left-right direction.

[0065] 5(c) is a simplified diagram showing a state in which the side edge seal 140 is attached to the layer-thickness regulating blade 100 and the side seal 200. In this state, the side edge seal 140 extends from the blade body 110 to the side seal 200 so as to cover the blade body 110, the surface layer 210, and a part of the base layer 220.

[0066] Next, a method for manufacturing the developing device 28 will be described. First, the supply roller seal 60 (see FIG. 2) is attached together with the supply roller 33 in the recess 53A shown in FIG. 6(a) and (b). Then, as shown in FIG. 7(a) and (b), the side seal 200 is attached to the housing 50 while being positioned by abutting against the protrusion 54 and the wall portion 55.

[0067] Specifically, positioning is performed by abutting the inner surface in the left-right direction of the protruding portion 222 of the side seal 200 against the protrusion 54 and abutting the downstream surface in the rotation direction of the protruding portion 222 against the wall portion 55. Next, as shown in Figures 8(a) and (b), the blade back seal 36 is attached to the upper part of the opening 52 in the housing 50 with double-sided tape TP. Specifically, the blade back seal 36 is attached to the housing 50 with the second portion 36D, which is the left-right end of the blade back seal 36, in contact with the inner surface in the left-right direction of the fourth base portion 221D, which is the downstream end of the side seal 200 in the rotation direction.

[0068] Thereafter, as shown in FIG. 9, the layer thickness regulating blade 100 is attached to the housing 50. At this time, the side seal 200 and the blade back seal 36 are compressed between the layer thickness regulating blade 100 and the housing 50. At this time, as shown in FIG. 5(a), since the double-sided tape TP is not provided on the second portion 36D of the blade back seal 36, the second portion 36D is free to deform in the left-right direction without being restrained by the double-sided tape TP. As a result, the second portion 36D compressed between the layer thickness regulating blade 100 and the housing 50 is deformed outward in the left-right direction and is strongly pressed against the fourth base portion 221D of the side seal 200. Therefore, it is possible to eliminate a gap at the joint between the side seal 200 and the blade back seal 36.

[0069] Thereafter, the side edge seal 140 is attached onto the blade body 110 and the side seal 200 of the layer thickness regulating blade 100. Then, other parts are appropriately assembled into the housing 50, whereby the developing device 28 is manufactured.

[0070] The effects of the developing device 28 thus configured will now be described. When a driving force is input to the developing device 28 , the developing roller 31 rotates while being in contact with the side seal 200 , the blade rubber portion 120 and the side edge seal 140 .

[0071] As a result, the lubricant on the fiber layer 211 of the side seal 200 moves inward in the left-right direction along the fiber FB and is supplied onto the protruding portion 222. The lubricant supplied onto the protruding portion 222 mixes with the toner, and a mixture of the toner and the lubricant is formed on the protruding portion 222. This mixture is held by the fiber FB of the first fiber region 213, and is further kneaded by the developing roller 31, thereby increasing the viscosity. Then, the mixture gradually piles up and spreads upstream in the rotation direction, forming a wall of the mixture. As a result, the mixture becomes a wall, and it is possible to suppress the toner scraped off by the blade rubber portion 120 from moving vigorously toward the side seal 200, and therefore it is possible to suppress the toner from leaking to the outside.

[0072] In a configuration in which the notch 121 (see FIG. 5B) is formed at each end of the blade rubber portion 120 in the left-right direction, the edge portion 123A of the notch 121 scrapes off a larger amount of toner on the developing roller 31 than the portion shifted inward in the left-right direction from the edge portion 123A of the blade rubber portion 120. The scraped off toner flows vigorously along the edge portion 123A toward the side seal 200 and mixes with the lubricant to form a mixture. The mixture is blocked by the edge portion 123A and is kneaded by the developing roller 31 to form a wall, which can prevent the toner from leaking to the outside. However, if a large amount of lubricant is supplied near the edge portion 123A, an excessive mixture of the toner and the lubricant is formed, creating a large wall, which blocks the toner excessively and reduces the fluidity of the toner.

[0073] In this embodiment, the downstream edge 213B of the first fiber region 213 overlapping with the protruding portion 222 coincides with the upstream edge 140A of the side edge seal 140 in the rotation direction. Therefore, the fiber FB of the first fiber region 213 supplies the lubricant onto the protruding portion 222 on the upstream side of the upstream edge 140A of the side edge seal 140 in the rotation direction. The fiber FB of the first fiber region 213 holds the mixture of the generated toner and lubricant, forming a wall of the mixture. On the other hand, near the edge 123A, specifically, downstream of the upstream edge 140A of the side edge seal 140 in the rotation direction, the fiber FB of the first fiber region 213 does not excessively supply the lubricant onto the protruding portion 222, and does not hold the mixture of the generated toner and lubricant. This allows the amount of the mixture near the edge 123A to be an appropriate amount, and it is possible to achieve both improvement in the fluidity of the toner and suppression of toner leakage.

[0074] As described above, according to this embodiment, in addition to the effects described above, the following effects can be obtained. By accurately positioning the left-right position of protruding portion 222 of side seal 200 with protrusion 54, it is possible to accurately control the amount by which protruding portion 222 overlaps edge portion 123A. By accurately controlling the amount of overlap between protruding portion 222 and edge portion 123A in this manner, it is possible to adjust the amount of mixture of lubricant and toner generated on protruding portion 222 to an appropriate amount, thereby achieving both improved toner fluidity near edge portion 123A and suppression of toner leakage.

[0075] By positioning the protrusion 54 closer to the downstream edge of the protruding portion 222 in the rotational direction than the upstream edge of the protrusion 222 in the rotational direction, the protrusion 54 can position the protruding portion 222 near the edge portion 123A, thereby improving the fluidity of the toner near the edge portion 123A and better suppressing toner leakage.

[0076] Since the fibers FB of the first fiber region 213 protrude further inward in the left-right direction than the inner edge 212E of the base sheet 212 and overlap the protruding portion 222, the lubricant can be moved along the fibers FB of the first fiber region 213 onto the protruding portion 222, so that a mixture can be produced well on the protruding portion 222 that overlaps the first fiber region 213.

[0077] The fibers FB of the second fiber region 214 hold the mixture of toner and lubricant on the base sheet 212, and the mixture forms a wall, which prevents the toner from leaking outside the developing device .

[0078] Since the base sheet 212 is positioned outboard of the blade rubber portion 120 in the left-right direction, the portion of the developing roller 31 that receives pressure from the side seal 200 can be shifted from the portion that receives pressure from the blade rubber portion 120. By shifting the portion that receives pressure from the side seal 200 from the portion that receives pressure from the blade rubber portion 120 in this manner, it is possible to prevent a rise in temperature of the surface of the developing roller 31 (the portion near the end surface 122 of the blade rubber portion 120), and therefore toner melting due to a rise in temperature can be prevented. In addition, it is possible to prevent the melted toner from adhering to the blade rubber portion 120.

[0079] Since the mixture can be held between the protruding portion 222 and the developing roller 31 by the fibers FB of the first fiber region 211A, the pressure applied to the mixture can be reduced compared to a structure in which the base sheet 212 and the fiber layer 211 are arranged overlapping on the protruding portion 222, since there is no base sheet 212 and the adhesive layer 230. By reducing the pressure applied to the mixture in this manner, the toner in the mixture can be prevented from melting. Furthermore, the melted toner can be prevented from adhering to the blade rubber portion 120.

[0080] Since the inner edge 213A of the first fiber region 213 is located laterally outward of the inner end of the edge portion 123A, the fluidity of the toner is prevented from being hindered by the mixture held at the tip of the fiber FB of the first fiber region 213.

[0081] Since the inner edge 213A of the first fiber region 213 is located laterally outboard of the inner surface 222C of the protrusion 222, the fluidity of the toner is more effectively prevented from being impeded by the mixture held at the tip of the fiber FB.

[0082] Since the inner edge 213A of the first fiber region 213 is located laterally inward of the center of the protrusion 222, the mixture held by the fibers FB of the first fiber region 213 on the protrusion 222 can be made larger.

[0083] By inclining the fibers FB with respect to the direction of rotation so that they are positioned inward in the left-right direction as they move downstream in the direction of rotation, the lubricant can be moved inward in the left-right direction along each fiber FB by the rotation of the developing roller 31, thereby enabling a good mixture to be generated on the protrusion 222.

[0084] By not applying lubricant to the side edge seal 140, the side edge seal 140 does not supply lubricant near the edge portion 123A, more specifically, onto the protrusion 222 downstream in the rotational direction from the upstream end edge 140A of the side edge seal 140. This makes it possible to adjust the amount of the mixture of toner and lubricant near the edge portion 123A to an appropriate amount, thereby improving the fluidity of the toner and suppressing toner leakage at the same time.

[0085] The present invention is not limited to the above-described embodiment, but can be used in various forms as exemplified below. In the following description, the same reference numerals are used to designate components having substantially the same structures as those in the above-described embodiment, and the description thereof will be omitted.

[0086] In the above embodiment, the downstream edge 213B of the first fiber region 213 in the rotational direction coincides with the upstream edge 140A of the side edge seal 140, but the present invention is not limited to this. As shown in Fig. 10, the downstream edge 213B of the first fiber region 213 in the rotational direction may be located upstream of the upstream edge 140A of the side edge seal 140 in the rotational direction. In this case, it is preferable that a downstream end edge 213B of the first fiber region 213 in the rotational direction is located downstream in the rotational direction from the center of the protruding portion 222 in the rotational direction. Furthermore, the length in the rotational direction between the downstream edge 213B of the first fiber region 213 in the rotational direction and the upstream edge 140A of the side edge seal 140 in the rotational direction is preferably within 5.0 mm. This makes it possible to satisfactorily improve the fluidity of the toner while suppressing toner leakage.

[0087] In the above embodiment, the inner edge 213A of the first fiber region 213 is disposed laterally outward of the inner end of the edge portion 123A, but the present invention is not limited to this. For example, the inner edge 213A of the first fiber region 213 may be disposed at the same position in the left-right direction as the inner end of the edge portion 123A, or may be disposed laterally inward of the inner end of the edge portion 123A.

[0088] In the above embodiment, the inner edge 213A of the first fiber region 213 is disposed laterally outward of the inner surface 222C of the protruding portion 222, but the present invention is not limited to this. For example, the inner edge 213A of the first fiber region 213 may be disposed at the same position in the left-right direction as the inner surface 222C of the protruding portion 222, or may be disposed laterally inward of the inner surface 222C of the protruding portion 222.

[0089] In the above embodiment, the inner edge 213A of the first fiber region 213 is disposed laterally inward from the left-right center of the protruding portion 222, but the present invention is not limited to this. For example, the inner edge 213A of the first fiber region 213 may be disposed at the same position in the left-right direction as the left-right center of the protruding portion 222, or may be disposed laterally outward from the left-right center of the protruding portion 222.

[0090] In the above embodiment, the surface layer 210 is composed of the fiber layer 211 and the base sheet 212, but the present invention is not limited to this. For example, the surface layer may be composed of a nonwoven fabric, a woven fabric, or the like.

[0091] In the above embodiment, the protrusion 222 is disposed laterally outward of the inner end of the edge portion 123A in the left-right direction, but the present invention is not limited to this. For example, the inner surface 222C of the protrusion 222 may be disposed at the same position in the left-right direction as the inner end of the edge portion 123A in the left-right direction, or may be disposed laterally inward of the inner end of the edge portion 123A in the left-right direction.

[0092] 10, the developing device 28 may include a lower film 35. The lower film 35 is a sheet-like member made of a resin such as polyethylene terephthalate, and extends along the axial direction of the developing roller 31 to contact the developing roller 31. The lower film 35 is formed to be longer in the left-right direction than the lower edge of the opening 52, and is disposed so as to contact the rear edge of the side seal 200. This makes it possible to prevent toner from leaking between the side seal 200 and the lower film 35.

[0093] In the above embodiment, the present invention is applied to the developing device 28 including the developing roller 31 and the toner storage chamber 34, but the present invention is not limited to this. For example, the present invention may be applied to other developing devices such as a process cartridge in which a developing cartridge and a drum unit are integrated, or a developing unit that is configured separately from a toner cartridge that stores toner and to which toner is supplied from the toner cartridge.

[0094] The elements described in the above embodiment and modified examples may be combined in any desired manner. [Explanation of symbols]

[0095] 28 Developing device 31 Developing roller 50 Case 54 Protrusion 100 Thickness-regulated blade 110 Blade body 120 Blade rubber part 121 Notch 140 Side edge seal 200 Side seal 210 Surface layer 211 Fiber layer 212 Base sheet 213 First Textile Division 214 Second Fiber Division 220 Base layer 222 Protrusion

Claims

1. A housing and A rotatable developing roller; a layer thickness regulating blade including a blade rubber portion that contacts a peripheral surface of the developing roller and has a notch at an end portion in an axial direction of the developing roller, and a blade body that supports the blade rubber portion; a side seal disposed between the housing and the developing roller so as to contact a peripheral surface of the developing roller at an end portion of the developing roller in the axial direction, the side seal having a surface layer that contacts the peripheral surface of the developing roller and a base layer disposed between the surface layer and the housing; a side edge seal that is disposed so as to come into contact with an end portion of the blade rubber portion in the axial direction and has an upstream end edge in a rotation direction of the developing roller that overlaps with the side seal; Equipped with the base layer has a protruding portion that protrudes inward in the axial direction from the side edge seal and has a portion that is located within a range of the cutout portion in the axial direction, the surface layer is a fiber layer made of a plurality of fibers that contacts the developing roller, the fiber layer being coated with a lubricant, and the surface layer has a base sheet in which the plurality of fibers in the fiber layer are implanted; the fiber layer has a first fiber region whose axially inner edge protrudes inward in the axial direction further than the axially inner edge of the base sheet and overlaps with the protruding portion when viewed from the surface layer toward the base layer, A developing device characterized in that the downstream edge of the first fiber region in the rotational direction is located at the same position in the rotational direction as the upstream edge of the side edge seal in the rotational direction, or upstream of the upstream edge of the side edge seal in the rotational direction.

2. 2 . The developing device according to claim 1 , wherein a downstream edge of the first fiber region in the rotational direction is located downstream in the rotational direction from a center of the protruding portion in the rotational direction.

3. 3. The developing device according to claim 1, wherein a length in the rotational direction between a downstream edge of the first fiber region and the edge of the side edge seal is 5.0 mm or less.

4. the fiber layer has a second fiber region whose axially inner edge does not protrude further inward in the axial direction than the axially inner edge of the base sheet, 4 . The developing device according to claim 1 , wherein a downstream edge of the second fiber region in the rotational direction is located downstream in the rotational direction of a downstream edge of the first fiber region in the rotational direction.

5. the housing has a protrusion that contacts an inner surface of the protruding portion in the axial direction, 5. The developing device according to claim 1, wherein the protrusion is located upstream of the notch in the rotational direction and is in contact with an end of the protruding portion downstream in the rotational direction.

6. The developing device according to claim 5 , wherein the housing includes a wall portion that comes into contact with a surface of the protrusion on a downstream side in the rotation direction.

7. 7 . The developing device according to claim 1 , wherein an axially inner edge of the first fiber region is positioned outward in the axial direction from an axially inner end of the cutout portion.

8. 8. The developing device according to claim 7, wherein the axially inner edge of the first fiber region is positioned outward in the axial direction from the axially inner surface of the protruding portion.

9. 9. The developing device according to claim 8, wherein an inner edge of the first fiber region in the axial direction is located more inward in the axial direction than a center of the protruding portion in the axial direction.

10. 10. The developing device according to claim 1, wherein the plurality of fibers are inclined with respect to the rotation direction so as to be positioned more inward in the axial direction as they move downstream in the rotation direction.

11. 11. The developing device according to claim 1, wherein the length of the plurality of fibers is 1.0 mm or more and 2.0 mm or less.

12. 12. The developing device according to claim 1, wherein the protruding portion is positioned outward in the axial direction relative to an inner end of the notch portion in the axial direction.

13. 13. The developing device according to claim 1, wherein an outer surface of the base layer in the axial direction is in contact with a side wall of the housing.

14. 14. The developing device according to claim 1, wherein the surface layer is a pile fabric.

15. a supply roller in contact with the developing roller; 7. The developing device according to claim 5, wherein the projection is located between the protruding portion and the supply roller.

16. 16. The developing device according to claim 1, wherein no lubricant is applied to the side edge seal.

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