Image forming apparatus

Abstract

To provide an image forming apparatus that can prevent residual toner scraped off by a cleaning blade from leaking from a gap to be sealed by side seals.SOLUTION: A pair of side seals 96 each have a first seal surface 96a, a second seal surface, and a third seal surface 96c. In a state before the side seal 96 is pressed against the surface of a photoreceptor drum 20, the first seal surface 96a is configured such that the length toward the downstream side in the direction of rotation of the photoconductor drum 20 is longer on a side of a surface having the third seal surface 96c than a side of a surface on the back thereof.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to an image forming apparatus including a photoconductor drum and a cleaning device that removes residual toner remaining on the surface of the photoconductor drum. [Background technology]

[0002] In an image forming apparatus, a latent image formed on a photosensitive drum is developed with toner, the toner image formed on the photosensitive drum is first transferred to an intermediate transfer body, and then transferred to printing paper, or directly transferred to printing paper, and the printing paper to which the toner image has been transferred is subjected to a fixing process to form an image.

[0003] When the toner image formed on the photosensitive drum is transferred to an intermediate transfer body or printing paper, toner that is not transferred remains on the photosensitive drum. This residual toner interferes with the next image formation, so it is configured to be cleaned by a cleaning device.

[0004] In such cleaning devices, those using an elastic cleaning blade that contacts the surface of the photosensitive drum are widely used. In order to prevent the residual toner scraped off by the cleaning blade from leaking out from both ends of the cleaning blade, Patent Document 1 describes providing L-shaped cleaning seal members at both ends of the cleaning member (cleaning blade) to prevent developer leakage. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2013-61626 A Summary of the Invention [Problem to be solved by the invention]

[0006] The cleaning seal member is curved and pressed against the surface of the photosensitive drum. However, if the cleaning seal member is configured to have the same length toward the downstream side in the rotation direction of the photosensitive drum from the side closer to the photosensitive drum to the side farther from the photosensitive drum before it is pressed against the surface of the photosensitive drum, then when it is curved and positioned as described above, the surface closer to the photosensitive drum is pulled, causing a gap to open between the cleaning seal member and the cleaning blade, and there is a risk that residual toner will leak out from the gap.

[0007] Such leakage of residual toner leads to staining of the charging roller and the like, so it is necessary to reduce the gap.

[0008] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide an image forming apparatus that can prevent residual toner scraped off by a cleaning blade from leaking out of a gap that should be sealed by a side seal. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, an image forming apparatus according to the present disclosure is an image forming apparatus including a photosensitive drum and a cleaning device that removes residual toner remaining on a surface of the photosensitive drum, the cleaning device including a cleaning blade that contacts the surface of the photosensitive drum along a longitudinal direction of the photosensitive drum and scrapes off the residual toner on a removal surface that faces the residual toner sent as the photosensitive drum rotates, and a pair of side seals that are pressed against the surface of the photosensitive drum at both longitudinal ends of the cleaning blade and prevent the residual toner from leaking out from both ends, the pair of side seals being each of the cleaning blades has a first sealing surface that faces the removal surface and prevents the residual toner from leaking out from between the removal surface, a second sealing surface that faces one of both longitudinal end surfaces of the cleaning blade and prevents the residual toner from leaking out from between the end surface, and a third sealing surface that faces the surface of the photosensitive drum and prevents the residual toner from leaking out from between the surface, and is characterized in that, before the side seal is positioned so that it is pressed against the surface of the photosensitive drum, the side of the first sealing surface having the third sealing surface has a longer length toward the downstream side in the rotation direction of the photosensitive drum than the back side of the first sealing surface.

[0010] The removal surface of the cleaning blade is sealed from residual toner leaking out by a first sealing surface of the side seal, both longitudinal end surfaces of the cleaning blade are sealed from residual toner leaking out by second sealing surfaces of the side seal, and the surface of the photosensitive drum is sealed from residual toner leaking out by a third sealing surface of the side seal.

[0011] The side seal is arranged so as to be pressed against the surface of the photosensitive drum, but if the side seal is configured to have the same length from the side closest to the photosensitive drum to the side furthest from the photosensitive drum downstream in the rotation direction of the photosensitive drum before the side seal is arranged so as to be pressed against the surface of the photosensitive drum after the side seal is arranged so as to be pressed against the surface of the photosensitive drum, when arranged as described above, the surface close to the photosensitive drum is pulled, so that a gap opens between the side of the first seal surface close to the photosensitive drum and the removal surface, and there is a risk that residual toner will leak out from between the first seal surface and the removal surface. Since residual toner leakage can lead to contamination of the charging roller, etc., it is necessary to reduce the gap as much as possible between the first seal surface and the removal surface.

[0012] According to the above-described configuration, before the side seal is positioned so that it is pressed against the surface of the photosensitive drum, the first sealing surface is configured so that its length is long toward the downstream side in the rotation direction of the photosensitive drum from the side having the third sealing surface to its back side. Therefore, even when it is positioned so that it is pressed against the surface of the photosensitive drum as described above, a gap is unlikely to open between the side closer to the photosensitive drum and the removal surface, thereby preventing residual toner from leaking out from between the first sealing surface and the removal surface.

[0013] In the image forming apparatus according to the present disclosure, the first sealing surface may be characterized in that, before the side seal is positioned so as to be pressed against the surface of the photosensitive drum, the first sealing surface is composed of a slope inclined with respect to a surface having the third sealing surface and a plane perpendicular to the back surface of the third sealing surface.

[0014] According to the above-described configuration, since the first sealing surface is inclined, when the side seal is positioned so as to be pressed against the surface of the photosensitive drum as described above, the gap with the removal surface is uniformly eliminated from the side closer to the photosensitive drum to the side furthest from the photosensitive drum, thereby preventing residual toner from leaking out from between the first sealing surface and the removal surface.

[0015] In the image forming apparatus according to the present disclosure, the side seal may be flat before the side seal is positioned so as to be pressed against the surface of the photosensitive drum, and the third sealing surface may be configured to curve along the surface of the photosensitive drum after the side seal is positioned so as to be pressed against the surface of the photosensitive drum.

[0016] According to the above-described configuration, after the side seal is positioned so as to be pressed against the surface of the photosensitive drum, the third sealing surface curves along and contacts the surface of the photosensitive drum, thereby preventing residual toner from leaking out along the surface of the photosensitive drum.

[0017] In the image forming apparatus according to the present disclosure, the side seal may have a two-layer structure having a felt layer and an elastic layer, and the side seal may be arranged so that the felt layer is pressed against the surface of the photosensitive drum.

[0018] According to the above-mentioned configuration, the felt layer of the side seal contacts the surface of the photosensitive drum, so the risk of residual toner leaking out is suppressed. The felt layer is a soft layer, so it exerts a weak pressure on the surface of the photosensitive drum. Therefore, by providing the elastic layer as described above, the felt layer can be pressed against the photosensitive drum by its elastic force. The felt layer is made of resin fibers such as polytetrafluoroethylene (PTFE). The elastic layer is made of rubber sponge such as natural rubber, chloroprene, ethylene propylene, silicone, nitrile, etc.

[0019] In the image forming apparatus according to the present disclosure, the side seal may be characterized in that, before the side seal is positioned so as to be pressed against the surface of the photosensitive drum, the felt layer is configured to have a longer length toward the downstream side in the direction of rotation of the photosensitive drum than the elastic layer.

[0020] According to the above-mentioned configuration, since the felt layer is longer toward the downstream side in the rotation direction of the photosensitive drum than the elastic layer, even if the first seal surface is curved as described above, a gap is unlikely to open between the portion of the first seal surface that corresponds to the felt layer and the removal surface, and therefore residual toner is prevented from leaking out from between the first seal surface and the removal surface.

[0021] In the image forming apparatus according to the present disclosure, the side seal may be disposed outside a width of an image forming area on the surface of the photosensitive drum.

[0022] The cleaning blade needs to have a longitudinal length equal to or greater than the width of the image forming area on the surface of the photosensitive drum so that the cleaning blade can scrape off residual toner across the width of the image forming area on the surface of the photosensitive drum. According to the above-mentioned configuration, the side seals are disposed outside the width of the image forming area on the surface of the photosensitive drum, so that residual toner can be prevented from leaking out from both longitudinal ends of the cleaning blade.

[0023] In the image forming apparatus according to the present disclosure, the side seal may be disposed inside the photosensitive drum in a longitudinal direction.

[0024] The side seal must be positioned so as to prevent the residual toner scraped off by the cleaning blade from leaking out along the surface of the photosensitive drum. With the above-described configuration, the side seal is positioned inside the longitudinal direction of the photosensitive drum, so that the residual toner can be prevented from leaking out along the surface of the photosensitive drum. Effect of the Invention

[0025] The image forming apparatus of the present disclosure has an advantage in that it is possible to prevent residual toner scraped off by the cleaning blade from leaking out of the gap that should be sealed by the side seal. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is an explanatory diagram illustrating a schematic configuration of an image forming apparatus. [Diagram 2] FIG. 2 is an explanatory diagram illustrating a configuration of a cleaning device. [Diagram 3] 3 is an explanatory diagram showing the main part of the cleaning device shown in FIG. 2 as viewed from the right. [Figure 4] FIG. 2 is an explanatory diagram of a side seal according to the first embodiment, where (a) is a left side view, (b) is a front view, and (c) is a bottom view. [Diagram 5] FIG. 5 is an explanatory diagram of a cleaning device equipped with the side seal shown in FIG. 4, taken along a cross-sectional view through a first sealing surface. [Figure 6] 5A to 5C are explanatory views of a side seal according to a comparative example, where (a) is a left side view, (b) is a front view, and (c) is a bottom view. [Figure 7] FIG. 7 is an explanatory diagram of a cleaning device equipped with the side seal shown in FIG. 6, taken along a cross-sectional view through a first sealing surface. [Figure 8] 10A, 10B, and 10C are explanatory views of a side seal according to a second embodiment, in which (a) is a left side view, (b) is a front view, and (c) is a bottom view. [Figure 9] FIG. 9 is an explanatory diagram of a cleaning device equipped with the side seal shown in FIG. 8, taken along a cross-sectional view through a first sealing surface. [Figure 10] 11A, 11B, and 11C are explanatory views of a side seal according to a third embodiment, in which (a) is a left side view, (b) is a front view, and (c) is a bottom view. [Figure 11] FIG. 11 is an explanatory diagram of a cleaning device equipped with the side seal shown in FIG. 10, taken along a cross-sectional view through a first sealing surface.

[0027] [Embodiment 1] A first embodiment of a tandem type color image forming apparatus according to the present disclosure will be described below. As shown in Fig. 1, the color image forming apparatus 1 includes four image forming units 2 (2K, 2C, 2M, 2Y) for forming toner images of black (K), cyan (C), magenta (M), and yellow (Y), a development power source, a transfer device 4, a fixing device 5, a paper feed device 6, a conveying device 7, a paper discharge tray 8, and a control unit (not shown) for controlling the color image forming apparatus 1. P is a printing paper. The color image forming apparatus 1 is the "image forming apparatus" in the claims.

[0028] The letters K, C, M, and Y of the image forming units 2K, 2C, 2M, and 2Y are used to distinguish between the image forming units corresponding to black (K), cyan (C), magenta (M), and yellow (Y), and may be omitted when no distinction is necessary. The same applies to the configuration of each part below.

[0029] Since the image forming units 2K, 2C, 2M, and 2Y basically have the same configuration, the image forming unit 2K that forms a black (K) toner image will be described below. The image forming unit 2K includes a photoconductor drum 20K, a charger 21K that charges the photoconductor drum 20K, an exposure device 22K that exposes the charged photoconductor drum 20K, a developing device 23K that develops a toner image on the exposed photoconductor drum 20K, and a cleaning device 9 that cleans the surface of the photoconductor drum 20K.

[0030] Photoconductor drum 20K is made of a photoconductor that is an insulator in the dark and a conductor when exposed to light. When it is negatively charged by charger 21K and then irradiated with light by exposure device 22K, the parts irradiated with light become conductors due to the photoconductor's properties, and the charge almost completely disappears, so toner adheres to them. On the other hand, parts not irradiated with light retain the charge, so toner does not adhere to them.

[0031] The exposure device 22K has a light emitting unit (for example, an LED). When the photoconductor drum 20K is exposed to light emitted from the light emitting unit, the potential of the exposed portion is weakened and an electrostatic latent image is formed.

[0032] The developing device 23K includes a developing tank 231K, an agitating device 232K, a toner supply roller 233K, a developing roller 234K, etc. The developing tank 231K is a container in which the developer is stored. The developer contains non-magnetic toner and magnetic carrier. The toner particle diameter is about 5 to 10 μm, and the carrier particle diameter is about 40 μm. The mixture ratio of the toner and the carrier is, for example, about 1:9.

[0033] The agitator 232K is rotated by a drive device (not shown) and agitates the developer stored in the developer tank 231K. The agitation by the agitator 232K generates friction between the toner and carrier contained in the developer, causing the toner to be negatively charged and the carrier to be positively charged. The agitator 232K is disposed near the toner supply roller 233K and conveys the developer to the toner supply roller 233K while stirring it. The toner supply roller 233K is rotated by a drive device (not shown) and carries the toner and carrier on the developing surface of the magnetic developing roller 234K.

[0034] A developing bias of a predetermined voltage value is applied to the developing roller 234K from the developing power source 3. The developing roller 234K forms a nip portion with the photoconductor drum 20K. In the nip portion, the toner receives a repulsive force from the developing roller 234K and is developed onto the photoconductor drum 20K.

[0035] The cleaning device 9 has a cleaning blade 91 that scrapes off residual toner on the surface of the photoconductor drum 20K that has not been completely transferred to the print paper P, and a charging device 92 that charges the photoconductor drum 20K. This allows the photoconductor drum 20K to prepare for the next printing. The toner scraped off by the cleaning blade 91 is collected in a waste toner box 93.

[0036] The developing power supply supplies a common developing bias to developing rollers 234K, 234C, 234M, and 234Y included in developing devices 23K, 23C, 23M, and 23Y of image forming units 2K, 2C, 2M, and 2Y.

[0037] The transfer device 4 includes primary transfer rollers 41K, 41C, 41M, and 41Y, an intermediate transfer belt 42, a drive roller 43, a driven roller 44, and a secondary transfer roller 45. A predetermined transfer voltage is applied to the primary transfer rollers 41K, 41C, 41M, and 41Y and the secondary transfer roller 45.

[0038] The primary transfer rollers 41K, 41C, 41M, and 41Y are disposed so as to face the photoconductor drums 20K, 20C, 20M, and 20Y of the image forming units 2K, 2C, 2M, and 2Y, respectively. The secondary transfer roller 45 is disposed so as to face the driven roller 44. The intermediate transfer belt 42 is stretched around the drive roller 43 and the driven roller 44, and when passing between the photoconductor drums 20K, 20C, 20M, and 20Y and the primary transfer rollers 41K, 41C, 41M, and 41Y, the toner images of each color formed on the photoconductor drums 20K, 20C, 20M, and 20Y are primarily transferred onto the intermediate transfer belt 42. The toner images of each color transferred onto the intermediate transfer belt 42 are transferred onto the printing paper P when the intermediate transfer belt 42 passes between the driven roller 44 and the secondary transfer roller 45.

[0039] The fixing device 5 sandwiches the print paper P between a heating roller with a built-in heat source and a pressure roller, and heats and pressure-feeds the toner image transferred to the print paper P, thereby fixing the toner image to the print paper P. The paper feeder 6 has a tray for loading the print paper P. The transport device 7 has a transport path for the print paper P and transport rollers and the like provided along the transport path. The paper output tray 8 is a tray on which the print paper P with an image printed thereon is placed.

[0040] The cleaning device 9 will be described in detail below. As shown in Figures 2 and 3, the cleaning device 9 has a cleaning blade 91 disposed facing the photoreceptor drum 20 in the longitudinal direction of the photoreceptor drum 20 so as to abut against the surface of the photoreceptor drum 20. The cleaning blade 91 is made of a material such as urethane rubber.

[0041] The cleaning blade 91 scrapes off the residual toner with a removal surface 91a that faces the residual toner sent with the rotation of the photoconductor drum 20. This removes the residual toner on the surface of the photoconductor drum 20, making the photoconductor drum 20 ready for the next printing. Note that the residual toner refers to the toner that has not been transferred to the printing paper P and remains on the surface of the photoconductor drum 20.

[0042] The residual toner scraped off by the cleaning blade 91 is stored in a waste toner box 93. The waste toner box 93 is provided with a toner screw 94 for transporting the stored residual toner.

[0043] Furthermore, the cleaning device 9 is provided with a seal blade 95 for preventing the residual toner contained in the waste toner box 93 from scattering outside the waste toner box 93 .

[0044] The sealing blade 95 is composed of a thin plate-like member, one end of which is fixed to the housing that constitutes the waste toner box 93, and the other end of which is freely formed, such as a resin such as urethane rubber, silicone, or PET, shaped into a film-like shape with a length equal to or greater than the axial width of the photosensitive drum 20 (approximately ±20 mm), a length in the direction of travel of the photosensitive drum 20 of approximately 10 mm, and a thickness of approximately 0.1 mm.

[0045] The sealing blade 95 is spaced apart from the surface of the photosensitive drum 20 in a base end region including the one end, and is positioned in a tip end region including the other end at a position where it makes surface contact with the surface of the photosensitive drum 20 over a distance of approximately 1 mm in the direction of travel of the photosensitive drum 20.

[0046] A pair of side seals 96 are disposed at both longitudinal ends of the cleaning blade 91. Each side seal 96 is provided to straddle from the cleaning blade 91 to the seal blade 95 at both longitudinal ends of the cleaning blade 91. Although the pair of side seals 96 differ in shape, they have the same basic configuration, and therefore will be described below without distinguishing between them.

[0047] The side seal 96 is disposed outside the width of the image forming area on the surface of the photosensitive drum 20 and inside the longitudinal direction of the photosensitive drum 20 .

[0048] 4(a), 4(b), and 4(c) show the side seal 96 before it is placed so as to be pressed against the surface of the photoconductor drum 20. The side seal 96 is made of a flat felt member. The felt member is made of resin fibers such as polytetrafluoroethylene (PTFE).

[0049] The side seal 96 has a first sealing surface 96a that faces the removal surface 91a and prevents residual toner from leaking out from between the removal surface 91a, a second sealing surface 96b that faces one of the longitudinal end surfaces 91b of the cleaning blade 91 and prevents residual toner from leaking out from between the end surface 91b, and a third sealing surface 96c that faces the surface of the photosensitive drum 20 and prevents residual toner from leaking out from between the end surface.

[0050] 4(a), the first seal surface 96a is shaped so that the surface side having the third seal surface 96c is located (extends) further downstream in the rotation direction of the photosensitive drum 20 than the back surface side, and in this embodiment, is configured as a slope inclined with respect to the surface having the third seal surface 96c and a plane perpendicular to the back surface. The side seal 96 is attached with double-sided tape at a predetermined position of the housing constituting the waste toner box 93.

[0051] Before the side seal 96 is positioned so that it is pressed against the surface of the photosensitive drum 20, the first sealing surface 96a is configured so that its length is long toward the downstream side in the rotation direction of the photosensitive drum from the side having the third sealing surface 96c to its back side. Therefore, even when the side seal 96 is positioned so that it is pressed against the surface of the photosensitive drum 20, as shown in Figure 5, a gap is unlikely to open between the side of the first sealing surface 96a closer to the photosensitive drum 20 and the removal surface 91a, thereby preventing residual toner from leaking out from between the first sealing surface 96a and the removal surface 91a.

[0052] As shown in Fig. 4(a), the first seal surface 96a is configured with an inclined surface, and therefore when the side seal 96 is arranged so as to be pressed against the surface of the photosensitive drum 20 as shown in Fig. 5, the gap between the first seal surface 96a and the removing surface 91a disappears uniformly from the side closer to the photosensitive drum 20 to the side farther from it (specifically, about 0 mm to 0.5 mm), thereby preventing residual toner from leaking out from between the first seal surface 96a and the removing surface 91a. In Fig. 5, the gap between the first seal surface 96a and the removing surface 91a is exaggerated for ease of understanding.

[0053] In addition, as shown in FIG. 5, the third seal surface 96c, which is the contact surface of the side seal 96 with the photosensitive drum 20, is pressed against the surface of the photosensitive drum 20 and curves along the surface of the photosensitive drum 20 to make contact, thereby preventing residual toner from leaking out along the surface of the photosensitive drum 20.

[0054] In this manner, the removal surface 91a of the cleaning blade 91 is sealed from residual toner leaking out by the first sealing surface 96a of the side seal 96, both longitudinal end surfaces of the cleaning blade are sealed from residual toner leaking out by the second sealing surface 96b of the side seal 96, and the surface of the photosensitive drum 20 is sealed from residual toner leaking out by the third sealing surface 96c of the side seal 96.

[0055] In contrast, as shown in Figures 6(a), 6(b), and 6(c), if the side seal 96 is configured to have the same length from the side having the third seal surface 96c to the back side thereof toward the downstream side in the rotation direction of the photosensitive drum 20 before being arranged so as to be pressed against the surface of the photosensitive drum 20, when the side seal 96 is arranged so as to be pressed against the surface of the photosensitive drum 20 as shown in Figure 7, the surface having the third seal surface 96c is pulled, so that a gap opens between the side of the first seal surface 96a closer to the photosensitive drum 20 and the removal surface 91a, and there is a risk that the residual toner will leak out from between the first seal surface 96a and the removal surface 91a. Since the leakage of residual toner leads to contamination of the charging roller, etc., it is necessary to reduce the gap as much as possible between the first seal surface 96a and the removal surface 91a.

[0056] [Embodiment 2] Next, a second embodiment of the present disclosure will be described with reference to the accompanying drawings. Here, configurations different from the first embodiment described above will be described, and the above description will be used for similar configurations.

[0057] 8(a), 8(b), and 8(c) show the side seal 96 before it is placed so as to be pressed against the surface of the photoreceptor drum 20. The side seal 96 is composed of a flat felt layer 96F and an elastic layer 96E. The felt layer is composed of resin fibers such as polytetrafluoroethylene (PTFE). The elastic layer is composed of rubber sponge such as natural rubber, chloroprene, ethylene propylene, silicone, nitrile, etc. The felt layer 96F and the elastic layer 96E are bonded together with an adhesive.

[0058] 8(a), the side seal 96 is configured such that the felt layer 96F is longer toward the downstream side in the rotation direction of the photoreceptor drum 20 than the elastic layer 96E before the side seal 96 is arranged so as to be pressed against the surface of the photoreceptor drum 20 and after the side seal 96 is arranged so as to be pressed against the surface of the photoreceptor drum 20. In this embodiment, the felt layer 96F is configured to be approximately 0.5 mm to 1 mm longer than the elastic layer 96E.

[0059] Since the felt layer 96F is configured to be longer toward the downstream side in the rotation direction of the photosensitive drum 20 than the elastic layer 96E, even if the felt layer 96F is curved as shown in Fig. 9, a gap is unlikely to open between the portion of the first seal surface 96a related to the felt layer 96F and the removal surface 91a, so that leakage of residual toner from between the first seal surface 96a and the removal surface 91a is suppressed. Note that in Fig. 9, the gap between the first seal surface 96a and the removal surface 91a is exaggerated for ease of understanding.

[0060] In this manner, the removal surface 91a of the cleaning blade 91 is sealed from residual toner leaking out by the first sealing surface 96a of the side seal 96, both longitudinal end surfaces of the cleaning blade 91 are sealed from residual toner leaking out by the second sealing surface 96b of the side seal 96, and the surface of the photosensitive drum 20 is sealed from residual toner leaking out by the third sealing surface 96c of the side seal 96.

[0061] [Embodiment 3] Finally, a third embodiment of the present disclosure will be described with reference to the accompanying drawings. Here, configurations different from the first and second embodiments described above will be described, and the above descriptions will be used to refer to similar configurations.

[0062] 10(a), 10(b), and 10(c) show the side seal 96 before it is arranged so as to be pressed against the surface of the photoreceptor drum 20. The side seal 96 is similar to the side seal 96 according to the second embodiment in that it is composed of a flat felt layer 96F and an elastic layer 96E.

[0063] As shown in FIG. 10(a), the side seal 96 is configured such that the portions of the felt layer 96F and the elastic layer 96E relating to the first sealing surface 96a are positioned downstream in the rotational direction of the photosensitive drum 20 relative to the back surface of the felt layer 96F and the back surface of the elastic layer 96E, and in this embodiment, are configured as inclined surfaces inclined with respect to the surface having the third sealing surface 96c and a plane perpendicular to the back surface of the felt layer 96F and the back surface of the elastic layer 96E.

[0064] Since the felt layer 96F is configured to be longer toward the downstream side in the rotation direction of the photosensitive drum 20 than the elastic layer 96E, even if it is arranged in a curved manner as shown in Figure 9, a gap is unlikely to open between the portion of the first sealing surface 96a relating to the felt layer 96F and the removal surface 91a.

[0065] At this time, the portions of the felt layer 96F and the elastic layer 96E relating to the first seal surface 96a are each formed of an inclined surface, so that when the side seal 96 is arranged so as to be pressed against the surface of the photosensitive drum 20 as shown in Fig. 5, the gap between the first seal surface 96a and the removal surface 91a disappears uniformly from the side closer to the photosensitive drum 20 to the side farther from the photosensitive drum 20 (specifically, about 0 mm to 0.5 mm), so that the residual toner is prevented from leaking out from between the first seal surface 96a and the removal surface 91a. Note that in Fig. 11, the gap between the first seal surface 96a and the removal surface 91a is exaggerated for ease of understanding.

[0066] In this manner, the removal surface 91a of the cleaning blade 91 is sealed from residual toner leaking out by the first sealing surface 96a of the side seal 96, both longitudinal end surfaces of the cleaning blade are sealed from residual toner leaking out by the second sealing surface 96b of the side seal 96, and the surface of the photosensitive drum 20 is sealed from residual toner leaking out by the third sealing surface 96c of the side seal 96.

[0067] The configurations disclosed in any of the above-described embodiments may be applied in combination with configurations disclosed in other embodiments, provided that no inconsistencies arise. Furthermore, the embodiments disclosed in this specification are merely examples, and the embodiments of the present disclosure are not limited thereto, and may be modified as appropriate within the scope of the present disclosure. [Explanation of symbols]

[0068] 1: Color image forming device (image forming device) 9,9K :Cleaning device 20: Photoconductor drum 91: Cleaning blade 91a:Removed surface 91b: End face 95: Seal blade 96: Side seal 96E: Elastic layer 96F: Felt layer 96a: First seal surface 96b: Second seal surface 96c: Third seal surface

Claims

1. An image forming apparatus including a photosensitive drum and a cleaning device that removes residual toner remaining on a surface of the photosensitive drum, The cleaning device includes: a cleaning blade that comes into contact with the surface of the photosensitive drum along the longitudinal direction of the photosensitive drum and scrapes off the residual toner with a removal surface that faces the residual toner conveyed by the rotation of the photosensitive drum; a pair of side seals disposed at both longitudinal ends of the cleaning blade so as to be pressed against the surface of the photosensitive drum and prevent the residual toner from leaking out from the both longitudinal ends; each of the pair of side seals has a first seal surface facing the removal surface to prevent the residual toner from leaking out from between the removal surface, a second seal surface facing one of both end surfaces in the longitudinal direction of the cleaning blade to prevent the residual toner from leaking out from between the end surface, and a third seal surface facing the surface of the photosensitive drum to prevent the residual toner from leaking out from between the surface, an image forming apparatus characterized in that, before the side seal is positioned so as to be pressed against the surface of the photosensitive drum, the first sealing surface is configured so that the side having the third sealing surface has a longer length toward the downstream side in the direction of rotation of the photosensitive drum than the back side thereof.

2. 2. The image forming apparatus according to claim 1, wherein the first sealing surface is composed of an inclined surface inclined with respect to a surface having the third sealing surface and a plane perpendicular to the back surface of the third sealing surface before the side seal is positioned so as to be pressed against the surface of the photosensitive drum.

3. the side seal has a flat plate shape before being arranged so as to be pressed against the surface of the photosensitive drum, 2. The image forming apparatus according to claim 1, wherein the third sealing surface is configured to curve along the surface of the photosensitive drum after the side seal is positioned so as to be pressed against the surface of the photosensitive drum.

4. The side seal has a two-layer structure including a felt layer and an elastic layer, 2. The image forming apparatus according to claim 1, wherein the side seal is disposed so that the felt layer is pressed against the surface of the photosensitive drum.

5. 5. The image forming apparatus according to claim 4, characterized in that, before the side seal is positioned so as to be pressed against the surface of the photosensitive drum, the felt layer is longer in length toward the downstream side in the direction of rotation of the photosensitive drum than the elastic layer.

6. 2. The image forming apparatus according to claim 1, wherein the side seal is disposed outside a width of an image forming area on the surface of the photosensitive drum.

7. 2. The image forming apparatus according to claim 1, wherein the side seal is disposed inside the photosensitive drum in the longitudinal direction.

Images