Image forming device

Abstract

The present invention provides an image forming device, which comprises: a roller whose rotating shaft is supported by a bearing; a supporting mechanism that supports the bearing and the accessory component of the bearing so as to be movable between a use position of the roller and a retreat position away from the use position; and a contact portion that is provided on one or both of the bearing and the accessory component and the supporting mechanism, and when the roller moves to the retreat position, the contact portion contacts a portion of the supporting mechanism or the accessory component that is opposite to the bearing and the accessory component.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus. Background Art

[0002] Japanese Patent Gazette No. 11-161038 discloses an image forming device comprising a transfer belt device having a transfer belt forming a transfer nip portion between the transfer belt device and an image carrier, a drive roller bearing for positioning the transfer belt device relative to a main body of the image forming device having a double-chamfered shape, and an upper portion of a receiving portion on the side of the main body of the image forming device that receives the drive roller bearing having a groove shape of a size that engages with the double-chamfered portion of the drive roller bearing, and a lower portion of the receiving portion having a hole shape of a size that can engage with the outer diameter of the bearing of the drive roller bearing. Summary of the Invention

[0003] The present disclosure provides an image forming device, which, when a roller movably arranged between a use position and a retracted position is moved to the retracted position, can suppress the end of the roller's rotating shaft from colliding with parts spaced apart around it and causing an impact, compared to a case where no contact portion is provided on one or both of the roller bearings and accessories and the supporting mechanism that movably supports them, and the contact portion contacts a portion of the opposing supporting mechanism or bearing when the bearings and accessories move to the retracted position.

[0004] According to a first aspect of the present disclosure, there is provided an image forming apparatus comprising:

[0005] a roller, the rotation axis of which is supported by a bearing;

[0006] a support mechanism that supports the bearing and its accessory components so as to be movable between a use position of the roller and a retracted position away from the use position; and

[0007] A contact portion is provided on one or both of the bearing and the accessory and the support mechanism, and when the roller moves to the retracted position, the contact portion contacts a portion of the support mechanism or the accessory facing the bearing and the accessory.

[0008] According to the second aspect of the present invention, the contact portion includes a first contact portion that comes into contact with a portion of the support mechanism when the bearing and the accessory member move to the retracted position.

[0009] According to the third embodiment of the present invention, the bearing has a positioning portion, which is arranged to be opposite to the end of the above-mentioned rotating shaft, limiting the position of the end of the rotating shaft when it is displaced, and the contact portion has a second contact portion on one of the positioning portion and the auxiliary component that contacts the auxiliary component or a part of the positioning portion.

[0010] According to the fourth aspect of the present invention, the first contact portion is provided so as not to contact the support mechanism when the bearing and the accessory component are moved to the use position.

[0011] According to a fifth aspect of the present disclosure, the first contact portion is configured to have an inclined surface that gradually approaches a portion of the support mechanism that faces and contacts the first contact portion when the bearing and the accessory member move to the retracted position.

[0012] According to the sixth aspect of the present invention, the second contact portion is configured to have a shape having a portion that exists at a position facing the end surface of the rotating shaft.

[0013] According to the seventh aspect of the present invention, the positioning portion is configured to be bent from the bearing so as to face the end surface of the rotating shaft, and the second contact portion is provided at least at a terminal end portion of the bend of the positioning portion.

[0014] (Effect)

[0015] According to the first scheme, when the image forming apparatus is transported in a state where a roller arranged to be movable between a use position and a retracted position is moved to the retracted position, compared with a case where no contact portion is provided on one or both of the roller bearing and its accessories and the supporting mechanism that movably supports them, it is possible to suppress the end of the roller's rotating shaft from colliding with components that exist at intervals around it and generating an impact, and the contact portion contacts a portion of the opposing supporting mechanism or bearing when the bearing and its accessories are moved to the retracted position.

[0016] According to the second aspect, compared with a case where the contact portion does not include a first contact portion that contacts a portion of the support mechanism, it is possible to reliably suppress the end portion of the roller's rotating shaft from colliding with a portion of the support mechanism to generate an impact.

[0017] According to the third aspect, compared with a case where the contact portion does not have a second contact portion that contacts an auxiliary member or a portion of the positioning portion, it is possible to reliably suppress the end of the roller's rotating shaft from colliding with a portion of the positioning portion in the bearing to generate an impact.

[0018] According to the fourth embodiment, compared with the case where the first contact portion is not arranged so as not to contact the support mechanism when the bearing and the accessory components move to the use position, the movement of the bearing and the accessory components when they move to the use position and the roller rotates will not be restricted or hindered by the contact of the first contact portion.

[0019] According to the fifth aspect, compared with a case where the first contact portion is not configured to have an inclined surface gradually approaching a portion of the support mechanism, the movement of the bearing and the accessory to the retracted position is not hindered and can be smoothly performed.

[0020] According to the sixth aspect, compared with a case where the second contact portion is not configured to have a shape that exists at a position facing the end face portion of the rotating shaft, it is possible to reliably suppress the end portion of the rotating shaft of the roller from colliding with a part of the positioning portion of the bearing to generate an impact.

[0021] According to the seventh aspect, compared with a case where the second contact portion is not provided at least at the bent terminal end of the positioning portion, the impact caused by the end of the roller's rotating shaft colliding with a part of the positioning portion in the bearing can be more reliably suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram showing the entire image forming apparatus according to Embodiment 1.

[0023] Figure 2 Yes Figure 1 FIG. 1 shows a supporting structure of a primary transfer roller in an image forming apparatus, Figure 2 (A) is a cross-sectional schematic diagram showing the state when it is moved to the use position. Figure 2 (B) is a schematic cross-sectional view showing a state when the device moves to the retracted position.

[0024] Figure 3 (A) is an enlarged image that moves to Figure 2 (A) is a schematic cross-sectional view of a portion of the state in the use position, Figure 3 (B) is a magnified image that moves to Figure 2 (B) is a schematic cross-sectional view of a portion of the state in the retracted position.

[0025] Figure 4 This is a front view showing part of the support structure of the primary transfer roller in a transparent manner.

[0026] Figure 5 Yes Figure 4 Front view of a portion of the supporting structure.

[0027] Figure 6 (A) is a front view showing a bearing of a primary transfer roller, Figure 6(B) means Figure 6 (A) Side view of the bearing.

[0028] Figure 7 (A) is an enlarged schematic diagram showing the state near the end of the primary transfer roller when it is moved to the use position. Figure 7 (B) is an enlarged schematic diagram showing the vicinity of the end portion of the primary transfer roller when the primary transfer roller has moved to the retracted position.

[0029] Figure 8 (A) is an enlarged schematic diagram showing the state near the end of the primary transfer roller when it is moved to the use position in a comparative example (a configuration example in which a contact portion is not provided). Figure 8 (B) is a schematic diagram showing an enlarged state of the vicinity of the end portion of the primary transfer roller when the primary transfer roller has moved to the retracted position in the comparative example. DETAILED DESCRIPTION

[0030] Hereinafter, the mode for carrying out the present disclosure will be described with reference to the drawings.

[0031] [Implementation Method 1]

[0032] Figure 1 and Figure 2 An image forming apparatus 1 according to Embodiment 1 of the present disclosure is shown. Figure 1 1 shows the overall structure of the image forming apparatus 1. Figure 2 The structure of a portion of the image forming apparatus 1 (mainly the secondary transfer device and its peripheral parts) is shown.

[0033] exist Figure 1 The arrows denoted by the symbols X, Y, and Z in the drawings represent the directions of width, height, and depth of the three-dimensional space assumed in the drawings. Furthermore, in the drawings, the circular mark at the intersection of the arrows in the X and Y (or Y and Z) directions indicates that the Z (or X) direction is vertically downward in the drawing.

[0034] Image forming apparatus 1 forms an image made of toner as a developer on paper 9, an example of a recording medium. Image forming apparatus 1 according to Embodiment 1 is configured as, for example, a printer that forms an image corresponding to image information input from an external device such as a data terminal.

[0035] like Figure 1As shown, the image forming device 1 has a frame 10 formed of a desired appearance shape, and the following components are provided in the internal space of the frame 10: an image forming device (2) that forms a colorant image based on image information; an intermediate transfer device (3) that temporarily holds and conveys the colorant image formed by the image forming device (2) and then transfers the colorant image to a paper (9) for the second time; a paper feeding device 4 that receives and delivers the paper 9 to be supplied to the position of the intermediate transfer device 3 for the second transfer; and a fixing device 5 that fixes the colorant image secondarily transferred by the intermediate transfer device 3 on the paper 9.

[0036] Here, the image information is information related to images such as characters, graphics, photos, and patterns. The housing 10 is a structure formed into a desired shape by various supporting members, exterior materials, and the like. Figure 1 The dashed-dotted line with an arrow in FIG. 1 represents a main conveyance path when the paper 9 is conveyed in the housing 10 .

[0037] The image forming apparatus 2 is composed of four image forming apparatuses 2Y, 2M, 2C, and 2K, each dedicated to forming a toner image of four colors: yellow (Y), magenta (M), cyan (C), and black (K).

[0038] Each of the four image forming devices 2 (Y, M, C, K) is configured to include a photosensitive drum 21, which is an example of an image holding mechanism that rotates in the direction indicated by arrow A. Around the photosensitive drum 21, there are arranged devices such as a charging device 22, an exposure device 23, a developing device 24 (Y, M, C, K), a primary transfer device 25, and a drum cleaning device 26. Figure 1 In FIG. 1 , all the symbols 21 to 26 are described only for the image forming apparatus 2K for black (K), and some of the symbols 21 to 26 are described for the image forming apparatuses 2 (Y, M, C) for other colors.

[0039] Among them, the charging device 22 is a device that charges the outer peripheral surface of the photosensitive drum 21 (the surface capable of forming an image) to a required surface potential. The exposure device 23 is a device that forms an electrostatic latent image of the required color components (Y, M, C, K) by exposing the outer peripheral surface of the photosensitive drum 21 based on image information. In addition, the developing device 24 (Y, M, C, K) is a device that develops the electrostatic latent image formed on the outer peripheral surface of the photosensitive drum 21 using developers (toners) of corresponding specified colors (Y, M, C, K) to form toner images of the specified four colors. The primary transfer device 25 is a device that electrostatically transfers the toner images of each color formed on the outer peripheral surface of the photosensitive drum 21 to the intermediate transfer device 3 (intermediate transfer belt 31). The drum cleaning device 26 is a device that cleans the outer peripheral surface of the photosensitive drum 21 by scraping away unnecessary toner, paper dust, and other excess materials adhering to the outer peripheral surface of the photosensitive drum 21.

[0040] In these image forming devices 2 (Y, M, C, K), each location where the photosensitive drum 21 (strictly speaking, the intermediate transfer belt 31 of the intermediate transfer device 3) faces the primary transfer device 25 serves as a primary transfer position TP1 where the primary transfer of the toner image is performed.

[0041] The intermediate transfer device 3 is a device configured to hold the toner images of each color formed by the image forming devices 2 (Y, M, C, K) through primary transfer and then transport them to a position where they are secondary transferred onto paper 9. The intermediate transfer device 3 is arranged above the image forming devices 2 (Y, M, C, K) within a housing 10.

[0042] The intermediate transfer device 3 includes an intermediate transfer belt 31 that primarily transfers and holds toner images from the photosensitive drums 21 of the image forming devices 2 (Y, M, C, K), and the following devices are arranged around the intermediate transfer belt 31 .

[0043] The intermediate transfer belt 31 is supported by a plurality of support rollers 32a to 32f disposed inside the intermediate transfer belt 31 so as to rotate (orbit) in the direction indicated by arrow B while sequentially passing through the primary transfer positions of the image forming devices 2 (Y, M, C, K).

[0044] The support rollers 32a to 32c are configured such that support roller 32a serves as a drive roller that receives rotational power from a drive device (not shown) to be rotationally driven, support roller 32b serves as a surface-exposed roller that cooperates with support roller 32a to maintain the belt position (surface) of the intermediate transfer belt 31 as it passes through the primary transfer position, and support roller 32c serves as a tension roller. Furthermore, support rollers 32d to 32f are configured such that support roller 32d serves as a surface-exposed roller for the intermediate transfer belt 31 before secondary transfer, support roller 32e serves as a secondary transfer auxiliary roller, and support roller 32f serves as a surface-exposed roller for the intermediate transfer belt 31 after it passes through the secondary transfer position. If support roller 32e is configured as a roller supplied with a secondary transfer voltage, the secondary transfer voltage is supplied from a power supply device (not shown).

[0045] In addition, the primary transfer device 25 of each image forming device 2 (Y, M, C, K) is arranged inside the intermediate transfer belt 31. The primary transfer device 25 also constitutes a part of the intermediate transfer device 3. Figure 1 、 Figure 2 As shown, the primary transfer device 25 of the first embodiment includes a primary transfer roller 250 that presses the intermediate transfer belt 31 against the photosensitive drum 21 at the primary transfer position TP1 and rotates in accordance with the intermediate transfer belt 31. The primary transfer roller 250 is supplied with a primary transfer current from a power supply device (not shown).

[0046] Furthermore, a secondary transfer device 35 is provided on the outer peripheral surface of the portion of the intermediate transfer belt 31 supported by the support roller 32e. The secondary transfer device 35 allows the paper 9 to pass through the intermediate transfer belt 31 and performs secondary transfer of the toner image on the intermediate transfer belt 31 onto the paper 9. The secondary transfer device 35 is a device that combines two support rollers and a transfer conveyor belt.

[0047] In addition, a belt cleaning device 36 is arranged on the outer peripheral surface of the portion of the intermediate transfer belt 31 supported by the supporting roller 32a. The belt cleaning device 36 removes unnecessary colorant and other excess materials remaining on the outer peripheral surface of the intermediate transfer belt 31 after the secondary transfer, thereby cleaning the outer peripheral surface of the intermediate transfer belt 31.

[0048] In the intermediate transfer device 3 , a portion where the secondary transfer device 35 contacts the outer peripheral surface of the intermediate transfer belt 31 serves as a secondary transfer position TP2 where the toner image is secondary transferred.

[0049] The paper feeder 4 accommodates and feeds paper 9 to be fed to the secondary transfer position TP2 of the intermediate transfer device 3. The paper feeder 4 is arranged inside the housing 10 below the image forming devices 2 (Y, M, C, K).

[0050] The paper feeding device 4 is configured by including a storage box 41 for arranging paper sheets, a feeding device 43 , and other devices.

[0051] The container 41 has a stacking plate 42 for stacking a plurality of paper sheets 9 in a desired orientation. The stacking plate 42 is a storage component that is installed so that it can be pulled out of the housing 10 to perform operations such as replenishing the paper sheets 9. The feeder 43 is a device that feeds out the paper sheets 9 stacked on the stacking plate 42 of the container 41 one by one using a feed device such as a plurality of rollers.

[0052] The paper 9 may be any recording medium such as plain paper, coated paper, or thick paper, as long as it can be conveyed within the housing 10 and to which a toner image can be transferred and fixed. The material and form of the paper 9 are not particularly limited.

[0053] The fixing device 5 is configured to fix the toner image secondary-transferred by the intermediate transfer device 3 onto the paper 9. The fixing device 5 is arranged inside the housing 10 at a position below the secondary transfer position TP2 of the intermediate transfer device 3 and downstream in the conveyance direction of the paper 9.

[0054] The fixing device 5 is configured such that a heating rotating body 51 , a pressurizing rotating body 52 and other devices are arranged in an internal space of a housing 50 provided with an introduction port and an outlet for the paper 9 .

[0055] The heating rotor 51 is a rotating body composed of a roller, a belt-pad, or the like, which rotates in the direction indicated by the arrow. Its outer surface is heated by a heating mechanism (not shown) so that the outer surface is maintained at a desired temperature. The pressurizing rotor 52 is a rotating body composed of a roller, a belt-pad, or the like, which rotates in contact with and following the heating rotor 51 under a desired pressure. The pressurizing rotor 52 can also be heated by a heating mechanism.

[0056] In the fixing device 5 , the contact area between the heating rotator 51 and the pressing rotator 52 constitutes a nip portion (fixing processing portion) FN that performs heating, pressing, and other processes for fixing the unfixed toner image on the paper 9 .

[0057] Figure 1 The dashed line portion indicated by the symbol Rt1 in the figure is a paper feed path that feeds the paper 9 located in the paper feed device 4 to the secondary transfer position TP2. The paper feed path Rt1 is configured by a plurality of conveying rollers 44a to 44c that sandwich and convey the paper 9, and a plurality of guide members (not shown) that ensure a conveyance space for the paper 9 and guide the conveyance of the paper 9.

[0058] in addition, Figure 1 The dashed line portion indicated by symbol Rt2 in the figure is a relay conveyance path for conveying the paper 9 after secondary transfer at the secondary transfer position TP2 of the intermediate transfer device 3 to the fixing device 5. The relay conveyance path Rt2 is configured by disposing a suction belt conveyor 46 or the like, for example.

[0059] in addition, Figure 1 The portion indicated by the dashed line symbol Rt3 in the figure is a discharge conveying path that conveys the fixed paper 9 between the fixing device 5 and the discharge outlet 13 to the paper discharge outlet 13 in the housing 10 and discharges it into the paper discharge accommodating portion (not shown). The discharge conveying path Rt3 is configured by a pair of conveying rollers or discharge rollers (not shown) and a plurality of guide members (not shown) that guide the conveyance of the paper 9.

[0060] The image forming apparatus 1 performs image formation, for example, by the following operation: Here, a case where a multicolor image, so-called full-color image, is formed by combining toner images of the four colors (Y, M, C, K) will be described as an example.

[0061] First, when the four image forming devices 2Y, 2M, 2C, and 2K receive a command to start forming a full-color image, the photosensitive drums 21, which rotate in the direction indicated by arrow A, are charged by the charging device 22, exposed by the exposure device 23, and developed by the developing devices 24 (Y, M, C, K). Consequently, a four-color toner image, decomposed into four color components (Y, M, C, K), is formed on each of the photosensitive drums 21 in the image forming devices 2Y, 2M, 2C, and 2K.

[0062] Next, in the intermediate transfer device 3, the four-color (Y, M, C, K) toner images formed on the photosensitive drum 21 by the image forming devices 2Y, 2M, 2C, and 2K undergo primary transfer at primary transfer position TP1 by the primary transfer device 25. These images are then transferred to the intermediate transfer belt 31, which rotates in the direction indicated by arrow B, and are then transported to the secondary transfer position TP2. Meanwhile, a sheet of paper 9 is transported from the paper feed device 4 via the paper feed and transport path Rt1 to the secondary transfer position TP2. Thus, at the secondary transfer position TP2, the four-color (Y, M, C, K) toner images on the intermediate transfer belt 31 are secondary transferred to the sheet of paper 9 by the secondary transfer of the secondary transfer device 35.

[0063] Next, the paper 9 after secondary transfer is conveyed to the fixing device 5 via the relay conveyance path Rt2, where it is introduced into and passes through the fixing process section of the fixing device 5. Thus, the toner image is fixed to the paper 9 through the fixing process of the fixing device 5. Finally, the paper 9 after fixing is discharged via the discharge conveyance path Rt3 to a discharged paper storage unit (not shown).

[0064] Through the above-described operation, a sheet of paper 9 on which a full-color image is formed is output.

[0065] When receiving a command to form a full-color image on a plurality of sheets 9, the image forming apparatus 1 repeats the above-described series of operations for the designated number of sheets. The image forming apparatus 1 can also form a monochrome image such as a black-and-white image.

[0066] Furthermore, the primary transfer roller 250 of the primary transfer device 25 in the image forming apparatus 1 has the following support structure.

[0067] First, if Figure 2 、 Figure 3 As shown in the figures, the primary transfer roller 250 is composed of a round rod-shaped rotating shaft 251 and an elastic layer 252, wherein the rotating shaft 251 is conductive and the elastic layer 252 is semi-conductive and is formed within the range of the rotating shaft 251 except for the two end portions (ends) 251a and 251b in the axial direction.

[0068] Then, if Figure 2 、 Figure 3 As shown in the figures, the two end portions 251a and 251b of the rotating shaft 251 of the primary transfer roller 250 are respectively supported by bearings 61 so as to be rotatable, and the bearings 61 are supported by a support frame 62 as an example of a support mechanism so as to be movable between a use position of the primary transfer roller 250 and a retreat position away from the use position.

[0069] Here, the use position of the primary transfer roller 250 is a position in which the primary transfer roller 250 contacts the intermediate transfer belt 31 at the primary transfer position TP1 and presses the intermediate transfer belt 31 against the photosensitive drum 21 to enable the primary transfer operation.

[0070] On the other hand, the retracted position of the primary transfer roller 250 is a position in which the primary transfer roller 250 is spaced a desired distance from the intermediate transfer belt 31. This retracted position is used, for example, when the intermediate transfer device 3 is being pulled out of the housing 10, or when transporting the image forming apparatus 1. Transporting refers to transporting the image forming apparatus 1 by a vehicle such as a truck or loading the image forming apparatus 1 into a location where the image forming apparatus 1 is installed.

[0071] like Figures 3 to 6 As shown in FIG. 1 and FIG. 2 , the bearing 61 in the first embodiment has a main body portion 611 , a spring receiving surface portion 612 , and a side wall surface portion 615 .

[0072] Among them, the main body 611 is a part provided with a bearing surface with a U-shaped cross-section and a guide groove 613, wherein the bearing surface is composed of a sliding bearing embedded from above in the two end portions 251a and 251b of the rotating shaft 251, and the guide groove 613 extends linearly in the up and down directions on the outer side of the side wall portion clamping the rotating shaft 251.

[0073] The spring receiving surface 612 is provided at the lower portion of the main body 611 and has a spring 64 ( Figure 3 ) of the upper end surface and the portion of the convex portion 612a.

[0074] The side wall surface portion 615 is a plate-shaped portion provided to stand from the lower portion of the main body portion 611 so as to face the end surfaces 251 c of the end portions 251 a and 251 b of the rotation shaft 251 with a predetermined interval therebetween.

[0075] The side wall surface 615 restricts the unnecessary movement of the rotating shaft 251 in the direction of both ends thereof and functions as a positioning portion for positioning the primary transfer roller 250 in the axial direction. Figure 4 、 Figure 6As shown in FIG. 1 and FIG. 2 , the side wall surface portion 615 is provided with a convex portion 616 on the inner surface portion facing the end surface 251 c of the rotation shaft 251 . The convex portion 616 protrudes so as to approach the end surface 251 c of the rotation shaft 251 .

[0076] The side wall surface 615 does not contact the end surface 251 c of the rotating shaft 251 but is spaced apart therefrom so that the side wall surface 615 does not hinder the rotation of the rotating shaft 251 and thus does not hinder the rotation of the primary transfer roller 250 .

[0077] like Figures 3 to 5 As shown in the figures, the support frame 62 in embodiment 1 is constructed to include: a substrate portion 621, which extends approximately parallel to the axial direction of the rotating shaft 251; a side plate portion 622, which stands upward at the end portion of the substrate portion 621 that is closer to the outside than the end portions 251a, 251b of the rotating shaft 251; and a pair of guide support portions 623, which stand upward at the inner side portion of the side plate portion 622 in the substrate portion 621 in a manner that clamps the two end portions 251a, 251b of the rotating shaft 251.

[0078] The base plate portion 621 is formed to extend to the portion facing the elastic layer 252 of the primary transfer roller 250. In addition, a surface and a convex portion for receiving the lower end of the spring 64 are provided at a portion of the base plate portion 621 facing the convex portion 612a of the spring receiving surface portion 612 of the bearing 61. For example, a coil spring such as Figure 3 As shown in FIG. 1 and FIG. 2 , the spring 64 is disposed between the spring receiving surface 612 of the bearing 61 and the base plate 621 and between the pair of guide support portions 623. Figure 3 As shown by the hollow arrow in , the spring 64 acts to bias (the main body 611 of) the bearing 61 upward toward the intermediate transfer belt 31 .

[0079] like Figure 3 、 Figure 4 As shown in FIG. 1 , the side plate portion 622 is configured such that its upper end is at a height that is opposite to at least a portion of the end surface 251c of the rotating shaft 251 of the primary transfer roller 250 when the primary transfer roller 250 is in the use position, across the side wall surface 615 of the bearing 61. Figure 4 As shown in FIG. 1 , the side plate portion 622 is provided with a shaft mounting hole 625 , into which the support shaft 69 of the swing support plate 68 is fitted and fixed. The swing support plate 68 is displaced so as to contact and separate the primary transfer roller 250 from the intermediate transfer belt 31 .

[0080] The pair of guide support parts 623 are provided with guide ridges 623 a on the inner side walls facing each other. The guide ridges 623 a extend linearly to guide the bearing 61 to slide in the vertical direction while being fitted in the guide grooves 613 of the main body 611 of the bearing 61 .

[0081] like Figure 3 、 Figure 4 As shown in the figures, when the guide protrusions 623a in a pair of guide support parts 623 of the support frame 62 are embedded in the guide grooves 613 of the main body 611, the bearing 61 is supported so as to be movable in a manner guided in the up and down directions, and is maintained by the spring 64 in a state of being urged upward with the required force.

[0082] Furthermore, the primary transfer roller 250 is swung in a desired direction by the swing support plate 68, and the side plate portion 622 of the support frame 62 is also swung via the support shaft 69. Therefore, the primary transfer roller 250 mounted on the support frame 62 via the bearing 61 is displaced in a manner of contacting and separating with the intermediate transfer belt 31. Figure 2 In the figure, the swing support plate 68 is not shown near the right end of the primary transfer roller 250 , but in reality, the swing support plate 68 is also arranged near the right end of the primary transfer roller 250 .

[0083] The primary transfer roller 250 is separated from the intermediate transfer belt 31 by the swing of the swing support plate 68 when, for example, the image forming device 2 (Y, M, C, K) provided with the primary transfer roller 250 is not forming a toner image.

[0084] In addition, if Figure 3 、 Figure 5 As shown, the support structure of the primary transfer roller 250 in Embodiment 1 includes a cover 63 as an example of an accessory component that covers the ends 251a, 251b of the rotating shaft 251 and the bearing 61 from above and laterally. The cover 63 is made of, for example, a non-conductive member.

[0085] The cover 63 in embodiment 1 is constructed to include: a top plate portion 631; a pair of side plate portions 632, which hang down from the side ends of the top plate portion 631 and are arranged opposite to the end portions 251a and 251b of the rotating shaft 251 with the main body portion 611 of the bearing 61 interposed therebetween; and an end panel portion 633, which hangs down from the end portion of the top plate portion 631 and is arranged opposite to the end face 251c of the rotating shaft 251 at a distance therefrom.

[0086] Among them, the top plate portion 631 is a plate-shaped portion having a width away from the rotating shaft 251 until it is located outside the main body portion 611 of the bearing 61, and a length from the inside of the side plate portion 622 of the support frame 62 to the outside of the swing support plate 68.

[0087] The pair of side plates 632 are plate-shaped portions that hang down from both widthwise ends of the top plate 631 and have a height dimension sufficient to cover the main body 611 of the bearing 61 from outside.

[0088] The end plate portion 633 is a plate-shaped portion that hangs down from the outer end portion in the longitudinal direction of the top plate portion 631 and is located between the side wall portion 615 of the bearing 61 and the side plate portion 622 of the support frame 62. The end plate portion 633 has a height dimension sufficient to cover the end surface 251c of the rotating shaft 251 from the outside. The end plate portion 633 is arranged to face both the side wall portion 615 of the bearing 61 and the side plate portion 622 of the support frame 62 with a desired spacing therebetween (a gap therebetween).

[0089] A portion (side plate portion 622 ) of the cover 63 is joined to the main body portion 611 of the bearing 61 , and the cover 63 is supported by a guide support portion 623 of the support frame 62 so as to be movable upward together with the bearing 61 .

[0090] In addition, in the supporting structure of the primary transfer roller 250, as shown in FIG. Figure 3 As shown, power supply terminals 65 for supplying a primary transfer voltage are arranged on the lower surface portions of the end portions 251 a and 251 b of the rotating shaft 251 on the inner side of the bearing 61 so as to be in contact with the power supply terminals 65 .

[0091] The power supply terminal 65 is formed of a conductive member and is held in a pressed state by a conductive spring 64 biased against the ends 251a and 251b of the rotating shaft 251. Furthermore, the power supply terminal 65 transmits a primary transfer voltage supplied from a power supply device (not shown) via a power transmission plate 66 fixed to a base plate portion 621 of the support frame 62.

[0092] Furthermore, in the supporting structure of the primary transfer roller 250 in the image forming apparatus 1, when the image forming apparatus 1 is transported, as shown in FIG. Figure 2 As shown in (B), the primary transfer roller 250 is moved to the retracted position.

[0093] At this time, the primary transfer roller 250 moved to the retracted position is in a state where the elastic layer 252 is spaced apart from the outer peripheral surface of the intermediate transfer belt 31 by a desired distance.

[0094] At this time, the ends 251a and 251b of the rotating shaft 251 of the primary transfer roller 250, together with the bearing 61 and the cover 63 as its accessory component, are moved to the lower side of the base plate portion 621 of the support frame 62 by a required distance. As a result, the ends 251a and 251b of the rotating shaft 251 moved to the retracted position, together with the side wall surface portion 615 of the bearing 61 and the end plate portion 633 of the cover 63, are closer to the side plate portion 622 of the support frame 62 and face the side plate portion 622 (see FIG. Figure 8 ).

[0095] Furthermore, when the primary transfer roller 250 moves to the retreat position, as shown in FIG. Figure 8 As shown, a gap S1 exists between the end plate portion 633 of the cover 63 and the side plate portion 622 of the support frame 62, and a gap S2 exists between the end plate portion 633 and the side wall portion 615 of the bearing 61. Furthermore, at this time, the primary transfer roller 250 itself is also in a state where it can be slightly displaced in its axial direction.

[0096] If the image forming device 1 is transported in a state where such gaps S1 and S2 exist, then when subjected to irregular external force during the transport, the first transfer roller 250 also moves irregularly in the axial direction, so that the end face 251c of the rotating shaft 251 of the first transfer roller 250 collides with the side wall surface 615 of the bearing 61, and then collides with the end panel portion 633 of the cover 63 through the side wall surface 615 of the bearing 61, and then collides with the side plate portion 622 of the support frame 62, sometimes causing unexpected impact.

[0097] In this case, if the impact caused by the collision is strong, for example, the side wall surface portion 615 of the bearing 61 or the end plate portion 633 of the cover 63 may be damaged or broken.

[0098] Therefore, in the image forming apparatus 1, as shown in FIG. Figures 3 to 6 As shown in the figures, a contact portion 7 is provided on the bearing 61 and its cover 63. When the primary transfer roller 250 moves to the retracted position, the contact portion 7 contacts the support frame 62 opposite to the bearing 61 and the cover 63 and a part of the bearing 61 (the side plate portion 622 and the side wall surface portion 615).

[0099] As the contact portion 7, a first contact portion 71 and a second contact portion 73 are used. The first contact portion 71 is arranged on the end panel portion 633 of the cover 63 and contacts a part of the support frame 62 (the side panel portion 622). The second contact portion 73 is arranged on the side wall surface portion 615 of the bearing 61 and contacts a part of the cover 63 (the end panel portion 633).

[0100] like Figure 3 、 Figure 5 、 Figure 7As shown in FIG. 1 and FIG. 2 , the first contact portion 71 is provided on the end plate portion 633 of the cover 63 as a rectangular parallelepiped ridge (or protrusion) extending linearly in the vertical direction.

[0101] like Figure 7 As shown in the figures, the first contact portion 71 has a height that allows it to enter the gap S1 between the end panel portion 633 of the cover 63 and the side plate portion 622 of the support frame 62 and remain in contact with the inner surface of the side plate portion 622 of the support frame 62, forming a raised or protruding state.

[0102] Furthermore, the first contact portion 71 is configured to have a portion located at a position opposed to a portion of the end surface 251c of the rotation shaft 251 from the upper end of the end surface plate portion 633 of the cover 63. Thus, compared to a case where the first contact portion 71 does not have a portion located at this position, when the end surface 251c of the rotation shaft 251 indirectly collides with the end surface plate portion 633 of the cover 63, it is possible to reliably suppress the impact on the end surface plate portion 633 of the cover 63 and the side plate portion 622 of the support frame 62.

[0103] In addition, if Figure 3 As shown in FIG. 5A and the like, the first contact portion 71 is provided so as not to contact the side plate portion 622 of the support frame 62 when the primary transfer roller 250 moves to the use position.

[0104] Furthermore, if Figure 7 As shown in FIG. 1 , the first contact portion 71 is configured to have an inclined surface (tapered surface) 71 c that gradually approaches the side plate portion 622 of the support frame 62 that contacts the first contact portion 71 when the primary transfer roller 250 moves to the retracted position.

[0105] In embodiment 1, as Figure 7 As shown in FIG. 1 , the upper end portion of the side plate portion 622 of the support frame 62 through which the first contact portion 71 passes is provided with a slope 622c that gradually descends toward the end plate portion 633 of the cover 63. The slope 622c serves as a guide surface for smoothly introducing the first contact portion 71.

[0106] On the other hand, Figures 3 to 7 As shown in FIG. 1 and FIG. 2 , the second contact portion 73 is provided on the side wall surface portion 615 of the bearing 61 as a raised portion (or protruding portion) having an inverted U-shape.

[0107] like Figure 7 As shown in the figures, the second contact portion 73 is located in the gap S2 between the side wall surface portion 615 of the bearing 61 and the end panel portion 633 of the cover 63, and has a height that is maintained in contact with the inner surface of the end panel portion 633 of the cover 63, forming a raised or protruding state.

[0108] In addition, the second contact portion 73 is configured to have a shape having a portion that exists at a position facing the end surface 251c of the rotating shaft 251. Figure 6 As shown in FIG. 1 and FIG. 2 , the second contact portion 73 in the first embodiment is configured to include a horizontal surface portion 731 and a pair of side wall surfaces 732 that extend downward from the left and right ends of the horizontal surface portion 731. Therefore, in this case, both the horizontal surface portion 731 and the pair of side wall surfaces 732 of the second contact portion 73 are located at a position facing the end surface 251c of the rotation shaft 251.

[0109] Furthermore, if Figure 6 As shown in FIG. 1 and FIG. 2 , the second contact portion 73 is provided at least at a bent terminal portion (an upper end portion in the first embodiment) of the end plate portion 633 of the cover 63 .

[0110] In the image forming apparatus 1 provided with the contact portion 7 (71, 73) as described above, when the image forming apparatus 1 is carried, compared to the case where the contact portion 7 (71, 73) is not provided, Figure 2 As shown in (B), when the first transfer roller 250 is moved to the retracted position, the end portions 251a, 251b of the rotating shaft 251 of the first transfer roller 250 can be prevented from colliding with components such as the side wall surface portion 615 of the bearing 61 and the end panel portion 633 of the cover 63 that are spaced apart around it and being impacted.

[0111] That is, in the image forming apparatus 1, when the primary transfer roller 250 moves to the retracted position, as shown in FIG. Figure 7 As shown in the enlarged view of (B) and the like, the first contact portion 71 enters the gap S1 between the end plate portion 633 of the cover 63 and the side plate portion 622 of the support frame 62, and maintains contact with the inner side surface of the side plate portion 622 of the support frame 62. Furthermore, the second contact portion 73 also includes a state in which, when moved to the use position, the second contact portion 73 is interposed in the gap S2 between the side wall portion 615 of the bearing 61 and the end plate portion 633 of the cover 63, and maintains contact with the inner side surface of the end plate portion 633 of the cover 63.

[0112] Therefore, when the image forming device 1 is subjected to irregular external force during transportation, even if the primary transfer roller 250 moves irregularly in the axial direction, the end face 251c of the rotating shaft 251 collides with the side wall surface 615 of the bearing 61. Since the above-mentioned gaps S1 and S2 do not exist, the impact of the collision with the side wall surface 615 of the bearing 61 can be prevented or reduced, including the side wall surface 615 of the bearing 61 affecting the end panel portion 633 of the cover 63 and the side plate portion 622 of the support frame 62.

[0113] As a result, even when the impact due to the collision is strong, the possibility of damage or breakage of, for example, the side wall surface portion 615 of the bearing 61 or the end plate portion 633 of the cover 63 can be reduced.

[0114] In addition, in the image forming device 1, since the first contact portion 71 that contacts the side plate portion 622 which is a part of the support frame 62 is provided, compared with the case where the first contact portion 71 is not provided, it is possible to reliably suppress the end portions 251a, 251b of the rotating shaft 251 of the primary transfer roller 250 from colliding with the side plate portion 622 of the support frame 62 and generating an impact.

[0115] In addition, in the image forming device 1, since the second contact portion 73 that contacts the side plate portion 632 which is a part of the cover 63 is provided, compared with the case where the second contact portion 73 is not provided, it is possible to reliably suppress the end portions 251a, 251b of the rotating shaft 251 of the primary transfer roller 250 from colliding with a part of the side wall surface portion 615 of the bearing 61 and generating an impact.

[0116] In addition, in the image forming apparatus 1, since the first contact portion 71 is arranged so as not to contact the side plate portion 622 of the support frame 62 when the first transfer roller 250 moves to the use position, compared with a case where it is not arranged in this way, when the first transfer roller 250 moves to the use position, the first contact portion 71 will not accidentally contact the side plate portion 622 of the support frame 62 to restrict and hinder the rotation operation of the first transfer roller 250.

[0117] In addition, in the image forming apparatus 1, since the first contact portion 71 is configured to have a slanted surface 71 c, and the slanted surface 71 c gradually approaches the side plate portion 622 of the support frame 62 that is in contact with the first contact portion 71 when the primary transfer roller 250 moves to the retracted position, compared to a case where the primary transfer roller 250 is configured to have no slanted surface 71 c, the primary transfer roller 250 can smoothly move to the retracted position without interfering with the movement of the bearing 61 and the cover 63 that move together.

[0118] In addition, in the image forming apparatus 1, since the second contact portion 73 is configured to have a shape having a portion located at a position opposite to the end face 251 c of the rotating shaft 251, compared to a case where the second contact portion 73 is configured to have a shape not having a portion located at such a position, when the end face 251 c of the rotating shaft 251 directly collides with the end panel portion 633 of the cover 63, the impact on the end panel portion 633 of the cover 63 and the side plate portion 622 of the support frame 62 adjacent thereto can be reliably suppressed.

[0119] In addition, in the image forming device 1, since the second contact portion 73 is set to exist at least at the curved upper end portion of the end panel portion 633 of the cover 63, it is possible to more reliably suppress the end face 251c of the rotating shaft 251 from colliding with a portion of the side wall surface portion 615 of the bearing 61 and generating an impact compared to the case where it is set to not exist at the upper end portion.

[0120] [Other embodiments]

[0121] The present disclosure is not limited to the contents exemplified in the above-mentioned embodiment 1, and includes, for example, the following modified examples.

[0122] The contact portion 7 may be provided on the side plate portion 622 of the support frame 62. In this case, the second contact portion 73 may be provided.

[0123] Furthermore, the contact portion 7 may be provided on the side plate portion 622 of the support frame 62, in addition to being provided on the side wall surface portion 615 of the bearing 61 and the end plate portion 633 of the cover 63. In this case, the contact portion 7 provided on the side plate portion 622 of the support frame 62 may be provided at a position opposite to the contact portion provided on the end plate portion 633 of the cover 63, or may be provided at a position not opposite to the contact portion.

[0124] The supporting structure of the roller provided with the contact portion 7 is not limited to the primary transfer roller 250 , and may be a supporting structure of other rollers in the image forming apparatus 1 .

[0125] In addition, the image forming apparatus 1 may be of other forms or types.

Claims

1. An image forming apparatus, wherein: The image forming device comprises: a roller whose rotation axis is supported by a bearing; and a support mechanism that supports the bearing and a cover as an accessory component of the bearing so as to be movable between a use position of the roller and a retreat position away from the use position; The bearing includes a main body portion receiving an end portion of the rotating shaft, and a side wall portion rising from the end portion of the main body portion so as to face an end face of the rotating shaft with a gap therebetween. The support mechanism includes: a base plate portion that supports the bearing and the cover so as to be movable on the lower side of the rotating shaft; and a side plate portion that stands upright from the end of the base plate portion so as to face at least a portion of the end surface of the rotating shaft with the side wall surface of the bearing interposed therebetween. The cover covers the bearing and the end of the rotating shaft from above and to the side, and comprises: a top plate portion, which is arranged above the end of the rotating shaft and is opposite to each other; and an end plate portion, which is suspended from the end of the top plate portion and is arranged opposite to each other, and exists between the side wall surface portion of the bearing and the side plate portion of the support mechanism with a gap therebetween. A contact portion is provided on one or both of the bearing and the cover and the support mechanism, and when the roller moves to the retreat position together with the bearing and the cover, the contact portion contacts the side plate portion of the support mechanism or the end panel portion of the cover opposite to the side wall surface portion of the bearing and the end panel portion of the cover.

2. The image forming apparatus according to claim 1, wherein The contact portion includes a first contact portion that comes into contact with the side plate portion of the support mechanism when the bearing and the cover move to the retracted position.

3. The image forming apparatus according to claim 1 or 2, wherein: The side wall surface of the bearing functions as a positioning portion that limits the position of the end portion when the rotating shaft is displaced. The contact portion includes a second contact portion that contacts a portion of the end panel portion or the positioning portion of the cover, in one of the positioning portion and the end panel portion of the cover.

4. The image forming apparatus according to claim 2, wherein: The first contact portion is provided so as not to contact the support mechanism when the bearing and the cover are moved to the use position.

5. The image forming apparatus according to claim 2 or 4, wherein: The first contact portion is configured to have a sloped surface that gradually approaches the side plate portion of the support mechanism that faces and contacts the first contact portion when the bearing and the cover move to the retracted position.

6. The image forming apparatus according to claim 3, wherein The second contact portion is configured in a shape in which a portion is located at a position facing the end surface of the rotation shaft.

7. The image forming apparatus according to claim 3, wherein: The positioning portion is configured to be curved from the bearing so as to face the end surface of the rotating shaft. The second contact portion is provided at least at a bent terminal portion of the positioning portion.

8. The image forming apparatus according to claim 6, wherein: The positioning portion is configured to be curved from the bearing so as to face the end surface of the rotating shaft. The second contact portion is provided at least at a bent terminal portion of the positioning portion.

Images