Operating mechanism and image forming device

Abstract

Embodiments of the present invention relate to an operating mechanism and an image forming device. The operating mechanism of the embodiment includes a direct-acting member, a rotating member, a rib, and an operating member. The direct-acting member includes a first engaging portion. The direct-acting member moves along an axis extending in a first direction. The rotating member includes a second engaging portion. The second engaging portion has a length in the first direction and in a circumferential direction around the axis. The second engaging portion engages with the first engaging portion in the first direction. The rotating member maintains the direct-acting member so that it can rotate around the axis and move in a direction along the axis when the first engaging portion and the second engaging portion are engaged. The rotating member limits the amount of movement of the direct-acting member along the axis to a predetermined distance via the second engaging portion. The rib is provided on the rotating member. The rib reinforces the rotating member to reduce deformation of the second engaging portion and suppress errors in the amount of movement relative to the distance of movement. The operating member rotates the direct-acting member around the axis.

Description

Technical Field

[0001] Embodiments of the present invention relate to an operating mechanism and an image forming apparatus. Background Art

[0002] As the exposure light source of the image forming apparatus, a linear light source such as an LED array may be used. The linear light source is held by an exposure head. The exposure head is supported by a lifting mechanism that lifts and lowers toward the photosensitive drum.

[0003] The lifting mechanism lifts the exposure head between a contact position where the exposure head is closest to the photosensitive drum unit and a separation position where a larger gap is formed between the exposure head and the photosensitive drum unit than at the contact position.

[0004] In particular, if the gap at the separation position is too small, there is a possibility that the photosensitive drum unit cannot be attached or detached, or cleaning of the exposure head becomes difficult. Summary of the Invention

[0005] The operating mechanism of the embodiment comprises: a linear motion member having a first engaging portion and moving along an axis extending in a first direction; a rotating member having a second engaging portion, the second engaging portion having a length in the first direction and in a circumferential direction around the axis and engaging with the first engaging portion in the first direction, the rotating member holding the linear motion member so as to be rotatable around the axis and movable in a direction along the axis when the first engaging portion and the second engaging portion are engaged, and limiting the amount of movement of the linear motion member along the axis to a predetermined movement distance by the second engaging portion; a rib provided on the rotating member for reinforcing the rotating member to reduce deformation of the second engaging portion and suppress an error in the amount of movement relative to the movement distance; and an operating member for rotating the linear motion member around the axis.

[0006] An image forming device according to an embodiment comprises: a photosensitive drum for carrying an electrostatic latent image; an exposure head for performing exposure in order to draw the electrostatic latent image on the photosensitive drum; and a lifting mechanism including the above-mentioned operating mechanism, wherein the lifting mechanism is locked to the direct-acting member of the operating mechanism in a manner interlocked with the direct-acting member and supports the exposure head so as to be movable in a second direction in which the exposure head approaches the photosensitive drum in accordance with a moving distance of the direct-acting member in the direction along the axis. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a schematic diagram showing a cross section of a configuration example of an image forming apparatus according to an embodiment.

[0008] Figure 2It is a perspective schematic diagram showing a state where the photosensitive drum unit is pulled out from the image forming apparatus according to the embodiment.

[0009] Figure 3 It is a perspective schematic diagram of an exposure unit and a base in the image forming apparatus according to the embodiment.

[0010] Figure 4 It is a perspective schematic diagram of an exposure unit and a lifting mechanism at a contact position in the image forming apparatus according to the embodiment.

[0011] Figure 5A It is a perspective schematic diagram of the exposure unit and the lifting mechanism at the separated positions on the rear side of the image forming apparatus according to the embodiment.

[0012] Figure 5B It is a perspective schematic diagram of the exposure unit and the lifting mechanism at the separated positions on the front side of the image forming apparatus according to the embodiment.

[0013] Figure 6 It is a perspective schematic diagram of an exposure unit and a lifting mechanism at a contact position in the image forming apparatus according to the embodiment.

[0014] Figure 7 It is a perspective schematic diagram of a first link and an operating mechanism in the image forming apparatus according to the embodiment.

[0015] Figure 8 This is an exploded perspective view of an operating mechanism in the image forming apparatus according to the embodiment.

[0016] Figure 9 It is a perspective schematic diagram showing an operating mechanism at a contact position in the image forming apparatus according to the embodiment.

[0017] Figure 10 It is along Figure 9 Schematic diagram of a cross section of the F10-F10 line.

[0018] Figure 11A It is a schematic perspective view showing a rotating member in the image forming apparatus according to the embodiment.

[0019] Figure 11B It is a schematic perspective view showing a rotating member in the image forming apparatus according to the embodiment.

[0020] Figure 12 It is a perspective schematic diagram of the exposure unit and the lifting mechanism at the separated positions in the image forming apparatus according to the embodiment.

[0021] Figure 13 It is a perspective schematic diagram showing the operating mechanism at the separated position in the image forming apparatus according to the embodiment.

[0022] Figure 14It is along Figure 13 Schematic diagram of a cross section of the F14-F14 line.

[0023] Figure 15 It is a schematic perspective view illustrating the function of a rotating member in the image forming apparatus according to the embodiment.

[0024] Figure 16 It is a schematic perspective view showing the operation of a rotating member of a comparative example. DETAILED DESCRIPTION

[0025] The operating mechanism of the embodiment includes a direct-acting member, a rotating member, a rib, and an operating member. The direct-acting member includes a first engaging portion. The direct-acting member moves along an axis extending in a first direction. The rotating member includes a second engaging portion. The second engaging portion has a length in the first direction and in a circumferential direction around the axis. The second engaging portion engages with the first engaging portion in the first direction. The rotating member holds the direct-acting member in a state where the first engaging portion and the second engaging portion are engaged, so that the member can rotate around the axis and move in a direction along the axis. The rotating member limits the amount of movement of the direct-acting member along the axis to a predetermined distance via the second engaging portion. The rib is provided on the rotating member. The rib reinforces the rotating member to reduce deformation of the second engaging portion and suppress errors in the amount of movement relative to the distance of movement. The operating member rotates the direct-acting member around the axis.

[0026] Hereinafter, an image forming apparatus according to an embodiment will be described with reference to the accompanying drawings. In the following figures, the same or corresponding components are denoted by the same reference numerals unless otherwise specified.

[0027] Figure 1 It is a schematic cross-sectional view showing an example of the overall structure of the image forming apparatus according to the embodiment.

[0028] like Figure 1 As shown, the image forming apparatus 100 of this embodiment includes a control panel 1 , a scanner unit 2 , a printer unit 3 , a sheet feeding unit 4 , a conveying unit 5 , a manual unit 10 , and a control unit 6 .

[0029] Hereinafter, when referring to relative positions in the image forming apparatus 100, the X1 direction, X2 direction, Y1 direction, Y2 direction, Z1 direction, and Z2 direction shown in the figure may be used. The X1 direction is when standing in front of the image forming apparatus 100 ( Figure 1The X2 direction is the direction opposite to the X1 direction. The Y1 direction is the direction from the back to the front of the image forming apparatus 100. The Y2 direction is the direction opposite to the Y1 direction. The Z1 direction is the vertically upward direction. The Z2 direction is the vertically downward direction. In cases where the X1 (Y1, Z1) and X2 (Y2, Z2) directions are irrelevant or both are included, the directions are simply referred to as the X (Y, Z) directions.

[0030] The plane having a normal in the X direction is referred to as the YZ plane, the plane having a normal in the Y direction is referred to as the ZX plane, and the plane having a normal in the Z direction is referred to as the XY plane. The ZX plane is a plane parallel to the conveyance direction of the sheet P in the image forming apparatus 100. The XY plane is a horizontal plane.

[0031] Unless otherwise specified, the shapes of the components of the image forming apparatus 100 will be described based on the arrangement posture within the image forming apparatus 100 .

[0032] The control panel 1 operates the image forming apparatus 100 through user operations.

[0033] The scanner unit 2 reads image information of the copy object as light and dark, and outputs the read image information to the printer unit 3 .

[0034] The printing section 3 forms an image on a sheet P based on image information from the scanning section 2 or external sources.

[0035] The printing unit 3 forms an output image (toner image) using a developer containing toner. The printing unit 3 transfers the toner image onto the surface of a sheet P. The printing unit 3 applies heat and pressure to the toner image on the surface of the sheet P to fix the toner image to the sheet P.

[0036] The sheet feeding section 4 feeds the sheets P to the printing section 3 one by one in accordance with the timing at which the printing section 3 forms a toner image.

[0037] The sheet feeding section 4 includes a paper feeding cassette 20 and a cassette paper feeding section 21 .

[0038] The paper feed cassette 20 stores sheets P of various sizes.

[0039] The cassette paper feed unit 21 is located above an end portion in the X1 direction of the paper feed cassette 20. The cassette paper feed unit 21 includes a pickup roller 22B, a paper feed roller 22A, and a separation roller 22C.

[0040] The pickup roller 22B conveys the sheet P required for image formation from the paper feed cassette 20 to the nip portion between the paper feed roller 22A and the separation roller 22C.

[0041] The paper feed roller 22A conveys the sheet P conveyed to the nip portion toward the conveying portion 5 .

[0042] When a plurality of sheets P are conveyed, the separation roller 22C separates one sheet P.

[0043] The transport unit 5 includes registration rollers 24 .

[0044] The registration rollers 24 align the leading end of the sheet P fed by the paper feed roller 22A at the nip N. The registration rollers 24 convey the sheet P according to the timing when the printing section 3 transfers the toner image to the sheet P. The registration rollers 24 convey the sheet P toward the transfer section 28 .

[0045] The printing section 3 includes image forming sections 25Y, 25M, 25C, and 25K, an exposure section 26 , an intermediate transfer belt 27 , a transfer section 28 , a fixing device 29 , and a transfer belt cleaning unit 31 .

[0046] The image forming sections 25Y, 25M, 25C, and 25K are arranged in order in the X1 direction.

[0047] The image forming units 25Y, 25M, 25C, and 25K each form the toner image transferred to the sheet P on the intermediate transfer belt 27 .

[0048] The image forming units 25Y, 25M, 25C, and 25K each include a photosensitive drum 7 . The image forming units 25Y, 25M, 25C, and 25K form yellow, magenta, cyan, and black toner images on the respective photosensitive drums 7 .

[0049] A charger, an exposure unit 26, a developer 8, a primary transfer roller, a cleaning unit, and a static eliminator are arranged around each photosensitive drum 7. The primary transfer roller faces the photosensitive drum 7. An intermediate transfer belt 27 is sandwiched between the primary transfer roller and the photosensitive drum 7.

[0050] Toner cartridges 32Y, 32M, 32C, and 32K are arranged above the image forming units 25Y, 25M, 25C, and 25K. The toner cartridges 32Y, 32M, 32C, and 32K contain yellow, magenta, cyan, and black toners, respectively.

[0051] The toners in the toner cartridges 32Y, 32M, 32C, and 32K are supplied to the image forming units 25Y, 25M, 25C, and 25K through toner supply pipes (not shown).

[0052] The exposure unit 26 irradiates light onto the surfaces of the charged photosensitive drums 7. The light emission is controlled based on the image information. The exposure unit 26 of this embodiment has a light source in which a plurality of light emitting elements are arranged along the Y1 direction. Figure 1In the illustrated example, the exposure section 26 is disposed below each of the image forming sections 25Y, 25M, 25C, and 25K.

[0053] Image information corresponding to yellow, magenta, cyan, and black is supplied to each exposure section 26 , and each exposure section 26 forms an electrostatic latent image based on the image information on the surface of each photosensitive drum 7 .

[0054] The intermediate transfer belt 27 is an endless belt. Tension is applied to the intermediate transfer belt 27 by multiple rollers abutting against its inner circumference. The intermediate transfer belt 27 is stretched flat. The inner circumference of the intermediate transfer belt 27 abuts against the support roller 28a at the position furthest from the center of the belt in the direction of stretching (X1). The inner circumference of the intermediate transfer belt 27 abuts against the transfer belt roller 23 at the position furthest from the center of the belt in the direction of stretching (X2).

[0055] The support roller 28a constitutes a part of the transfer section 28. The support roller 28a guides the intermediate transfer belt 27 to the secondary transfer position.

[0056] The transfer belt roller 23 guides the intermediate transfer belt 27 to the cleaning position.

[0057] Image forming units 25Y, 25M, 25C, and 25K, excluding the primary transfer roller, are sequentially arranged in the X1 direction on the lower surface of the intermediate transfer belt 27. The image forming units 25Y, 25M, 25C, and 25K are spaced apart from each other in the region between the transfer belt roller 23 and the backup roller 28a.

[0058] When the toner image reaches the primary transfer position, a transfer bias is applied to each primary transfer roller of the image forming units 25Y, 25M, 25C, and 25K. Each primary transfer roller primarily transfers the toner image on the surface of each photosensitive drum 7 onto the intermediate transfer belt 27 .

[0059] The transfer section 28 is arranged on the intermediate transfer belt 27 at a position adjacent to the image forming section 25K.

[0060] The transfer unit 28 includes a backup roller 28a and a secondary transfer roller 28b. The secondary transfer roller 28b and the backup roller 28a sandwich the intermediate transfer belt 27. The position where the secondary transfer roller 28b and the intermediate transfer belt 27 abut against each other is the secondary transfer position.

[0061] The transfer section 28 transfers the charged toner image on the intermediate transfer belt 27 to the surface of the sheet P at the secondary transfer position. The transfer section 28 applies a transfer bias to the secondary transfer position. The transfer section 28 transfers the toner image on the intermediate transfer belt 27 to the sheet P using the transfer bias.

[0062] The fixing device 29 applies heat and pressure to the sheet P. The fixing device 29 fixes the toner image transferred to the sheet P by the heat and pressure. The fixing device 29 is arranged above the transfer section 28 .

[0063] The transfer belt cleaning unit 31 faces the transfer belt roller 23 , sandwiches the intermediate transfer belt 27 , and scrapes toner off the surface of the intermediate transfer belt 27 .

[0064] Conveyance paths 30A and 30B for conveying the sheet P from downward to upward are sequentially formed between the registration roller 24 and the transfer section 28 , and between the transfer section 28 and the fixing device 29 , respectively.

[0065] Each of the conveyance paths 30A, 30B, and 30C includes a conveyance guide and conveyance rollers that face each other with the sheet P interposed therebetween.

[0066] The manual unit 10 supplies sheets P with images formed thereon to the printing section 3. When the manual tray 13 is in use, it is opened by rotating clockwise as shown in the solid line. Sheets P of various sizes can be placed on the opened manual tray 13.

[0067] The manual unit 10 includes a pickup roller, a paper feed roller, and a separation roller similar to those of the sheet feeding portion 4 .

[0068] The control unit 6 controls the entire image forming apparatus 100 and its components. For example, the control unit 6 controls the control panel 1, scanner 2, printer 3, sheet feeder 4, conveyor 5, and manual unit 10 to convey a sheet P and form an image on the sheet P.

[0069] As a device configuration of the control unit 6 , for example, a processor such as a CPU (Central Processing Unit) may be used.

[0070] The detailed structure of each exposure section 26 will be described. The structure of each exposure section 26 is common to each other. Hereinafter, the image forming sections 25Y, 25M, 25C, and 25K disposed above the exposure section 26 will be referred to as the image forming section 25 without being distinguished from each other.

[0071] Figure 2 It is a schematic side view showing a photosensitive drum, an exposure unit, and a mechanism in the image forming apparatus according to the first embodiment. Figure 3 This is an exploded view of the exposure section and mechanisms in the image forming apparatus according to the first embodiment. Figure 4 It is a perspective schematic diagram of an exposure unit and a lifting mechanism at a contact position in the image forming apparatus according to the embodiment. Figure 5A 、 Figure 5BIt is a perspective schematic diagram showing an exposure section and a support member in the image forming apparatus according to the first embodiment. Figure 6 It is a perspective schematic diagram of an exposure unit and a lifting mechanism at a contact position in the image forming apparatus according to the embodiment. Figure 7 It is a perspective schematic diagram of a first link and an operating mechanism in the image forming apparatus according to the embodiment.

[0072] As in Figure 2 As exemplified by the image forming section 25Y in FIG. 1 , each image forming section 25 is formed as a photosensitive drum unit 25D excluding the exposure section 26 and the primary transfer roller.

[0073] The photosensitive drum unit 25D can be pulled out in the Y1 direction while the exposure section 26 and the primary transfer roller remain inside the printing section 3 .

[0074] Each exposure unit 26 is disposed on a base 11 provided in the printing unit 3 .

[0075] like Figure 3 As shown, the exposure units 26 are separated from each other in the X direction on the base 11. The X-direction arrangement position of each exposure unit 26 corresponds to the exposure position toward each photosensitive drum 7. The height of the lower surface of each exposure unit 26 is determined by the base 11.

[0076] like Figure 4 As shown, the exposure section 26 includes an exposure head 33 and a lifting mechanism 34. The exposure head 33 forms an electrostatic latent image on the photosensitive drum 7.

[0077] like Figure 5A 、 Figure 5B As shown, the exposure head 33 includes an exposure device 33a, a holder 33b, a supporting member 33f, and a biasing member 33c.

[0078] The exposure device 33a is elongated in one direction. It includes multiple light-emitting elements and a circuit board that causes the light-emitting elements to emit light. For example, the multiple light-emitting elements are a solid-state light-emitting element array. The multiple light-emitting elements are arranged along the longitudinal direction of the exposure device 33a. The longitudinal direction of the exposure device 33a is the Y direction within the image forming apparatus 100. For example, the multiple light-emitting elements may be an LED array, an organic EL array, or the like.

[0079] The plurality of light emitting elements in the exposure device 33 a emit light in response to a driving current supplied from the circuit board.

[0080] Exposure device 33a includes a lens for focusing light from multiple light-emitting elements. The lens focuses the light from each of the multiple light-emitting elements at a focal point. The lens is not particularly limited as long as it can independently focus the light from each of the multiple light-emitting elements. For example, a self-focusing lens array may be used as the lens.

[0081] The holder 33b holds the exposure device 33a. The holder 33b is longer than the exposure device 33a in the Y1 direction and the Y2 direction. The holder 33b is supported by the supporting member 33f so as to be able to move forward and backward in the direction toward the photosensitive drum 7.

[0082] The advancing and retreating direction of the holder 33 b is a direction along the optical axis of the light emitted from the exposure device 33 a .

[0083] The incident angle of the optical axis with respect to the surface of the photosensitive drum 7 is not particularly limited. For example, the optical axis may be inclined with respect to the normal line at the incident position toward the photosensitive drum 7. The optical axis may also be inclined with respect to the vertical plane.

[0084] In this embodiment, the optical axis of the exposure device 33 a extends in the Z direction along the vertical plane, and the advancing and retreating direction of the holder 33 b is the Z direction.

[0085] like Figure 5A As shown, an abutment surface 33dR and a positioning portion 33eR are provided on the upper surface of the end portion of the holder 33b in the Y2 direction.

[0086] The abutment surface 33dR abuts against a spacer 25dR provided on the housing 25A of the photosensitive drum unit 25D. The spacer 25dR protrudes downward from the lower surface of the housing 25A. The abutment surface 33dR creates a predetermined gap between the housing 25A and the retaining member 33b near the spacer 25dR. This predetermined gap is large enough to align the focal position of the lens of the exposure head 33 with the surface of the photosensitive drum 7. In this embodiment, the abutment surface 33dR is provided on the upper surface of the retaining member 33b between the positioning portion 33eR and the end of the exposure head 33 in the Y2 direction.

[0087] The positioning portion 33eR engages with a pin 25eR provided on the housing 25A to position the exposure head 33 in the Y and X directions relative to the photosensitive drum 7 in the housing 25A. For example, the positioning portion 33eR is a circular hole into which the cylindrical portion of the pin 25eR is removably engaged.

[0088] like Figure 5B As shown, an abutment surface 33dF and a positioning portion 33eF are provided on the upper surface of the end portion of the holder 33b in the Y1 direction.

[0089] The abutment surface 33dF abuts against a spacer 25dF provided on the housing 25A. The spacer 25dF protrudes downward from the lower surface of the housing 25A. The abutment surface 33dF creates a predetermined gap between the housing 25A and the retaining member 33b near the spacer 25dF. This predetermined gap is large enough to align the focal position of the lens of the exposure head 33 with the surface of the photosensitive drum 7. In this embodiment, the abutment surface 33dF is provided on the upper surface of the retaining member 33b between the positioning portion 33eF and the end of the exposure head 33 in the Y1 direction.

[0090] The exposure head 33 abuts against the spacers 25 dR and 25 dF at the abutment surfaces 33 dR and 33 dF, and is thereby positioned in the Z direction so that the focal position of the lens coincides with the surface of the photosensitive drum 7 .

[0091] The positioning portion 33eF engages with a pin 25eF provided on the housing 25A to position the exposure head 33 in the X direction. For example, the positioning portion 33eF is a long hole extending in the Y direction. For example, the positioning portion 33eF has a short width in the X direction that allows the cylindrical portion of the pin 25eF to be inserted and removed therein, and a long width that is longer than the diameter of the cylindrical portion of the pin 25eF.

[0092] The support member 33f supports the holder 33b so as to be able to advance and retreat in the Z direction. A plurality of biasing members 33c are arranged on a bottom surface portion 33g of the support member 33f.

[0093] Each urging member 33 c urges the end surface of the holder 33 b in the Z2 direction along the Z1 direction away from the bottom surface portion 33 g.

[0094] The biasing force of each biasing member 33 c is large enough to press the contact surfaces 33 dR and 33 dF against the spacers 25 dR and 25 dF with a constant load, respectively.

[0095] The number of retaining elements 33b in the biasing member 33c is not particularly limited. In this embodiment, they are positioned at two locations on either end of the bottom portion 33g in the Y direction. The pressing position of each biasing element 33c in the retaining element 33b is slightly inward of the abutting surfaces 33dR and 33dF in the Y direction. In this embodiment, the pressing position of each biasing element 33c is approximately on the back side of both ends of the exposure device 33a.

[0096] The urging member 33c is not particularly limited as long as it can urge the holder 33b. For example, the urging member 33c may be a compression coil spring that expands and contracts in the Z direction.

[0097] An engagement hole 33fa connected to the lifting mechanism 34 is provided on the lower side of the bottom surface portion 33g supporting each urging member 33c.

[0098] The lifting mechanism 34 supports the exposure head 33 so that it can move forward and backward toward the photosensitive drum 7. In this embodiment, the lifting mechanism 34 supports the exposure head 33 so that it can move along the Z direction. For example, Figure 4 、 Figure 6 The lifting mechanism 34 shows a state in which the exposure head 33 is lifted to the uppermost position, that is, the contact position.

[0099] At the contact position, the contact surfaces 33dF and 33dR contact the spacers 25dF and 25dR, respectively.

[0100] For example, Figure 5A 、 Figure 5B 、 Figure 12 The lifting mechanism 34 shows a state in which the exposure head 33 is lowered to the lowest position, that is, the separated position.

[0101] At the separated position, the contact surfaces 33dF and 33dR are separated from the spacers 25dF and 25dR, respectively, and a gap larger than the gap at the contact position is formed between the housing 25A and the exposure head 33 along the Z direction.

[0102] like Figure 4 As shown, the lifting mechanism 34 includes a support member 34C, a first link 34A, a link mechanism 34B, a biasing member 34D, and an operating mechanism 34E.

[0103] The support member 34C is arranged below the exposure head 33 . The support member 34C is provided at the lower portion of the exposure unit 26 .

[0104] The support member 34C includes a bottom surface portion 34Ca, a guide plate 34Cb (see Figure 6 ), supporting portion 34Cc and locking portion 34Cd.

[0105] The bottom portion 34Ca is a flat surface parallel to the XY plane and is long in the Y direction. The support member 34C houses the components of the lifting mechanism 34 except the support member 34C.

[0106] like Figure 6 As shown, a plurality of guide plates 34Cb are provided on the bottom surface portion 34Ca, spaced apart along the Y direction. Each guide plate 34Cb is composed of two flat plates facing each other in the X direction and parallel to the YZ plane. The guide plates 34Cb guide the movement of the first link 34A in the Y direction.

[0107] like Figure 4 As shown, a plurality of support portions 34Cc are provided in accordance with the number of link mechanisms 34B. In the present embodiment, support portions 34Cc are provided at two locations in the longitudinal direction of the bottom surface portion 34Ca, corresponding to two link mechanisms 34B.

[0108] The support portion 34Cc supports the third link 34Bb of the link mechanism 34B so as to be rotatable within a plane parallel to the YZ plane.

[0109] like Figure 5A 、 Figure 5B As shown, each support portion 34Cc protrudes from the bottom surface portion 34Ca in the Z1 direction.

[0110] The structure of the support portion 34Cc is not particularly limited as long as it can rotatably support the third link 34Bb. In the present embodiment, the support portion 34Cc is a bearing that rotatably supports the engagement shaft 34Bbb of the third link 34Bb.

[0111] like Figure 6 As shown in FIG. 1 , the locking portion 34Cd protrudes in the Z1 direction from the end portion in the Y2 direction of the bottom surface portion 34Ca. The locking portion 34Cd locks the end portion in the Y2 direction of the urging member 34D.

[0112] The first link 34A is arranged on the bottom surface portion 34Ca along the longitudinal direction of the bottom surface portion 34Ca. The first link 34A is long in the Y direction.

[0113] The first link 34A is supported on the bottom surface 34Ca so as to be movable in the Y direction. When the exposure head 33 is moved to the contact position, the first link 34A moves to the farthest end in the Y2 direction relative to the support member 34C. When the exposure head 33 is moved to the separated position, the first link 34A moves to the farthest end in the Y1 direction relative to the support member 34C.

[0114] like Figure 7 As shown, the first link 34A has a bottom plate 34Aa. The bottom plate 34Aa is parallel to the XY plane and is long in the Y direction. Side plates 34Ab protrude in the Z1 direction from both ends of the bottom plate 34Aa in the X direction. Each side plate 34Ab is inserted into each guide plate 34Cb (see Figure 6 ) between them, and can move in the Y direction along each guide plate 34Cb.

[0115] Through holes 34Ac that penetrate the side plates 34Ab in the X direction are formed at both ends of the side plates 34Ab in the Y direction.

[0116] The bottom plate 34Aa has openings 34Ad formed near each through hole 34Ac, each of which penetrates the bottom plate 34Aa in the Z direction. Each opening 34Ad is formed on the Y2 direction side of each through hole 34Ac.

[0117] like Figure 4As shown, a support portion 34Cc and a third link 34Bb supported by the support portion 34Cc are arranged inside each opening 34Ad. Each opening 34Ad is formed to a size such that the support portion 34Cc and the third link 34Bb do not contact each other within the range of movement of the first link 34A in the Y direction.

[0118] like Figure 7 As shown, a locking portion 34Ae for locking the urging member 34D is provided at the end portion of the first link 34A in the Y2 direction.

[0119] A fixing shoulder screw 38 (see FIG. 1 ) is provided at the end portion of the first link 34A in the Y1 direction. Figure 8 ) fixed portion 34Af.

[0120] like Figure 4 As shown, the link mechanisms 34B are provided between the support member 34C and the holder 33b at two locations separated from each other in the Y direction. Each link mechanism 34B supports the holder 33b at two locations, one at the end of the holder 33b in the Y1 direction and the other at the end in the Y2 direction. Each link mechanism 34B connects the support member 34C and the holder 33b and is also connected to the first link 34A.

[0121] Each link mechanism 34B converts the movement of the first link 34A in the Y1 direction into movement in the Z1 direction, thereby moving the holder 33b away from the support member 34C in the Z1 direction. Similarly, each link mechanism 34B converts the movement of the first link 34A in the Y2 direction into movement in the Z2 direction, thereby moving the holder 33b in the Z2 direction toward the support member 34C.

[0122] The structure of each link mechanism 34B is not particularly limited as long as it can move the exposure head 33 in the Z direction in accordance with the movement of the first link 34A. The structure of each link mechanism 34B is the same.

[0123] In the present embodiment, each link mechanism 34B includes a second link 34Ba and a third link 34Bb.

[0124] Two second links 34Ba are provided, sandwiching the third link 34Bb in the X-direction. The shapes of the second links 34Ba are symmetrical with respect to the YZ plane. The following describes the shape of the second link 34Ba located on the X1 side of the third link 34Bb. Regarding the shape of the second link 34Ba located on the X2 side of the third link 34Bb, the X1 and X2 directions can be interchanged in the following description.

[0125] The second link 34Ba is longer than the third link 34Bb.

[0126] The second link 34Ba connects the first link 34A and the support member 33f. The second link 34Ba includes a first engagement shaft 34Baa, a second engagement shaft 34Bab, and a third engagement shaft 34Bac.

[0127] The first engagement shaft 34Baa is an engagement portion connected to the holder 33b, and projects in the X2 direction at an end portion in the longitudinal direction of the second link 34Ba.

[0128] The second engagement shaft 34Bab is an engagement portion connected to the first link 34A, and an end portion on the opposite side of the end portion where the first engagement shaft 34Baa is formed in the longitudinal direction projects in the same direction as the first engagement shaft 34Baa.

[0129] The third engagement shaft 34Bac is an engagement portion connected to the third link 34Bb, and protrudes in the same direction as the first engagement shaft 34Baa between the first engagement shaft 34Baa and the second engagement shaft 34Bab.

[0130] The first engagement shaft 34Baa is rotatably engaged with the engagement hole 33fa of the support member 33f. The second link 34Ba is connected to the support member 33f via the first engagement shaft 34Baa.

[0131] The second engagement shaft 34Bab is rotatably engaged with the through hole 34Ac of the first link 34A. The second link 34Ba is connected to the first link 34A via the second engagement shaft 34Bab.

[0132] The third engagement shaft 34Bac is rotatably engaged with an engagement hole 34Bba provided at an end portion in the longitudinal direction of the third link 34Bb. The second link 34Ba is connected to the third link 34Bb via the third engagement shaft 34Bac.

[0133] The third link 34Bb connects the second link 34Ba and the support member 34C. An engagement hole 34Bba and an engagement shaft 34Bbb are formed at both ends in the longitudinal direction of the third link 34Bb.

[0134] The third engaging shafts 34Bac of the second links 34Ba are inserted through the engaging holes 34Bba. The engaging holes 34Bba hold the third engaging shafts 34Bac coaxially. The third link 34Bb is connected to the second links 34Ba so as to be rotatable about the center of the engaging hole 34Bba.

[0135] The engagement shaft 34Bbb is rotatably engaged with the support portion 34Cc. The third link 34Bb is connected to the support portion 34Cc via the engagement shaft 34Bbb.

[0136] The urging member 34D urges the first link 34A in the Y2 direction within the range of movement of the first link 34A. The structure of the urging member 34D is not particularly limited as long as it can urge the first link 34A in the Y2 direction.

[0137] For example Figure 6 As shown, the biasing member 34D may also be a tension coil spring that expands and contracts in the Y direction. In this case, the biasing member 34D has a first hook 34Da at its end in the Y2 direction and a second hook 34Db at its end in the Y1 direction. The first hook 34Da is locked with the locking portion 34Cd, and the second hook 34Db is locked with the locking portion 34Ae.

[0138] The urging member 34D is stretched longer than its natural length at the contact position with the exposure head 33. The urging member 34D is further stretched longer than its length at the contact position at the separated position with the exposure head 33.

[0139] The operating mechanism 34E will be described.

[0140] Figure 8 This is an exploded perspective view of an operating mechanism in the image forming apparatus according to the embodiment. Figure 9 It is along Figure 7 Schematic diagram of a cross section of the F9-F9 line. Figure 10 It is along Figure 9 Schematic diagram of a cross section of the F10-F10 line. Figure 11A 、 Figure 11B It is a schematic perspective view showing a rotating member in the image forming apparatus according to the embodiment.

[0141] The operating mechanism 34E is used for the operation of raising and lowering the exposure head 33 by the lifting mechanism 34 .

[0142] like Figure 8 As shown, the operating mechanism 34E includes a linear motion member 37 , a shoulder screw 38 , an operating member 39 , and a rotating member 35 .

[0143] The linear motion member 37 is cylindrical and elongated in the Y direction. A cylindrical hole 37a extends through the interior of the linear motion member 37, extending from a first end e1 in the Y1 direction to a second end e2 in the Y2 direction. A cylindrical surface 37b is formed on the outer periphery of the end portion in the Y1 direction of the linear motion member 37. The cylindrical surface 37b is coaxial with the hole 37a.

[0144] At the end portion of the cylindrical surface 37 b in the Y2 direction, a protrusion 37 c that is long in the Y direction protrudes radially outward from the cylindrical surface 37 b.

[0145] A plurality of grooves 37e extending in the Y2 direction are formed on the outer circumference of the cylindrical surface 37b from the end in the Y2 direction to the second end e2 of the linear motion member 37. The grooves 37e are spaced at equal intervals in the circumferential direction.

[0146] A protrusion 37d is formed between circumferentially adjacent grooves 37e. The distal end of each protrusion 37d has the same outer diameter as the cylindrical surface 37b.

[0147] The first engaging portion 36 is provided on the outer peripheral portion of the linear motion member 37 where the protrusion 37d is formed. The first engaging portion 36 is a protrusion that protrudes radially outward from the protrusion 37d.

[0148] The first engaging portion 36 is provided at a longitudinally intermediate portion of the outer peripheral portion where the protrusion 37 d is formed.

[0149] The shape of the first engaging portion 36 is not particularly limited, as long as it is a protrusion that protrudes radially and can press the rotating member 35 in the Y2 direction. For example, in this embodiment, the first engaging portion 36 is a cylinder with a central axis extending radially. The outer diameter of the first engaging portion 36 is not particularly limited, as long as it provides strength to withstand the load when pressing the rotating member 35. For example, in this embodiment, the outer diameter of the first engaging portion 36 is slightly larger than the circumferential width of the protrusion 37d.

[0150] The shoulder screw 38 has a cylindrical portion 38 a , a screw head 38 c , and an external thread 38 b .

[0151] The cylindrical portion 38a is long in the Y direction. The length of the cylindrical portion 38a is substantially the same as that of the first engaging portion 36. The outer diameter of the cylindrical portion 38a is large enough to be rotatable coaxially with the hole portion 37a of the first engaging portion 36.

[0152] A screw head 38c having a larger diameter than the cylindrical portion 38a is formed at the end of the cylindrical portion 38a in the Y1 direction. An external thread 38b is coaxially formed with the cylindrical portion 38a at the end of the cylindrical portion 38a in the Y2 direction. The external thread 38b can be screwed into the fixing portion 34Af.

[0153] When the shoulder screw 38 is screwed into the fixing portion 34Af with the external thread 38b inserted through the hole 37a on the first end e1 side of the linear motion member 37, the shoulder screw 38 is fixed to the fixing portion 34Af with the longitudinal direction of the cylindrical portion 38a oriented in the Y direction. The cylindrical portion 38a between the fixing portion 34Af and the screw head 38c supports the linear motion member 37 so that it can rotate about the central axis O of the cylindrical portion 38a.

[0154] like Figure 9As shown, the second end e2 of the linear motion member 37 supported by the shoulder screw 38 is adjacent to the Y1 direction side of the fixing portion 34Af.

[0155] like Figure 8 As shown, the operating member 39 has a cylindrical portion 39a, a rod 39b, and a guide flange 39c.

[0156] The cylindrical portion 39a has an inner diameter that allows it to fit with the cylindrical surface 37b of the linear motion member 37 and the distal end surfaces of each protrusion 37d. A U-shaped groove 39e, which is elongated in the Y direction, is formed at the end of the cylindrical portion 39a in the Y2 direction. The U-shaped groove 39e has a groove width that is approximately the same as the circumferential width of the protrusion 37c. When the protrusion 37c is inserted into the U-shaped groove 39e, the cylindrical portion 39a, which is fitted with the cylindrical surface 37b, is prevented from rotating in the circumferential direction of the linear motion member 37.

[0157] When the cylindrical portion 39 a is fitted in a state where the linear motion member 37 is stopped from rotating, the operation member 39 is coupled to the linear motion member 37 so as to be rotatable around the central axis O.

[0158] The rod 39b protrudes radially outward from the outer circumference of the cylindrical portion 39a from the end in the Y1 direction of the cylindrical portion 39a to the middle of the cylindrical portion 39a. The surface of the rod 39b is formed with appropriate concave and convex shapes so that the user can easily rotate it by hand.

[0159] The guide flange 39c protrudes radially outward from the outer circumference of the cylindrical portion 39a, which is closer to the Y2 direction than the rod 39b. The guide flange 39c is plate-shaped and parallel to the ZX plane. The guide flange 39c is housed within the guide groove 35g of the rotating member 35 so as to be rotatable within a plane parallel to the ZX plane.

[0160] The rotating member 35 supports the linear motion member 37 so as to be rotatable about the central axis O and to be able to advance and retreat in the Y direction. The rotating member 35 has an outer shape in which a cylindrical body projects in the Y2 direction from a plate-shaped portion parallel to the ZX plane.

[0161] For example, the rotating member 35 may be manufactured by resin molding.

[0162] like Figure 10 As shown, the rotating member 35 includes a base material 35 a , a main body portion 35 b , and ribs 40 , 41 .

[0163] The base material 35a is in the shape of a plate parallel to the ZX plane. In this embodiment, the base material 35a is reinforced in the plate thickness direction by a plurality of ribs 35f protruding in the Y1 direction.

[0164] The base material 35a is fixed to the side plate of the support member 34C (see Figure 5B The base material 35a has threaded holes through which fixing screws are inserted.

[0165] like Figure 11A 、 Figure 11B As shown in FIG. 1 , the main body 35b is connected to the base material 35a. The main body 35b is in the shape of a tube protruding from the base material 35a in the Y2 direction.

[0166] An inner hole 35c is formed within the main body 35b, extending along the Y direction. The inner hole 35c also extends through the base material 35a. The inner surface 35d of the inner hole 35c is a cylindrical surface with the Y direction as its axial direction. The axial, radial, and circumferential directions of the main body 35b are, respectively, the direction along the central axis of the inner hole 35c, the direction perpendicular to the central axis, and the direction circumferentially around the central axis.

[0167] The shape of the outer surface 35j of the main body 35b is not particularly limited. For example, the outer surface 35j may be a polygonal cylindrical surface, a cylindrical surface, etc. In this embodiment, the outer surface 35j is a cylindrical surface.

[0168] like Figure 11B As shown, a hole 35i is formed on the surface of the substrate 35a in the Y1 direction. The hole 35i is coaxial with the inner hole 35c and has a diameter larger than the inner diameter of the inner hole 35c. The depth of the hole 35i is shallower than the thickness of the substrate 35a.

[0169] The inner wall of the hole 35i is formed with a plurality of protrusions 35k that protrude radially of the hole 35i and extend in the Y direction.

[0170] The hole 35i allows the distal end of the cylindrical portion 39a of the operation member 39 to be inserted rotatably in the circumferential direction of the hole 35i.

[0171] like Figure 11A 、 Figure 11B As shown, a through hole 35e is formed in the main body 35b. The through hole 35e extends from the outer surface 35j toward the inner surface 35d. The through hole 35e, as viewed from the side of the main body 35b, has a general shape that spirals clockwise as it advances from the axial middle portion of the main body 35b in the Y1 direction. The through hole 35e is formed over, for example, approximately half the circumference of the main body 35b.

[0172] like Figure 9 As shown, the opening width of the through hole 35 e in the Y direction is wider than the outer diameter of the first engaging portion 36 .

[0173] The inner peripheral surface S of the opening formed by the through hole 35e includes flat portions S1, S2, a spiral portion S3, flat portions S4, S5 (see Figure 11B )、S6(Refer to Figure 11A ) and the tilted face S7 (refer to Figure 11A ). The inner peripheral surface S is a plane or a curved surface perpendicular to the inner surface 35d.

[0174] like Figure 11B As shown, the flat surface portion S1 is a flat surface parallel to the radial direction and the axial direction of the main body portion 35b.

[0175] Plane portion S2 is a plane extending along the circumference of main body portion 35b and is parallel to the ZX plane. Plane portion S2 smoothly connects to the end of planar portion S1 in the Y2 direction via an arc-shaped curved surface. When viewed in the Y1 direction, planar portion S2 extends clockwise relative to planar portion S1.

[0176] The spiral portion S3 is smoothly connected to the end of the planar portion S2 on the side opposite to the planar portion S1 via an arc-shaped curved surface. The spiral portion S3 has a length in the Y direction and in the circumferential direction around the central axis O. In this embodiment, the spiral portion S3 is a spiral surface that turns clockwise as it advances in the Y1 direction.

[0177] Plane portion S4 is a plane extending along the circumference of main body portion 35b and is parallel to the ZX plane. Plane portion S4 smoothly connects to the end of spiral portion S3 in the Y1 direction via an arc-shaped curved surface. When viewed in the Y1 direction, planar portion S2 extends clockwise relative to spiral portion S3.

[0178] The flat portion S4 is formed at a position away from the surface of the substrate 35 a in the Y2 direction in the Y2 direction.

[0179] The flat surface portion S5 is a flat surface parallel to the radial direction and the axial direction of the main body portion 35b and is smoothly connected to the end portion of the flat surface portion S4 on the opposite side to the spiral portion S3 via an arc-shaped curved surface.

[0180] The end of the plane portion S5 in the Y1 direction is located in the middle of the substrate 35a in the thickness direction. The plane portion S5 intersects with the bottom surface of the hole 35i.

[0181] like Figure 11A As shown, planar portion S6 is a plane extending in the circumferential direction of main body portion 35b and is parallel to the ZX plane. Planar portion S6 smoothly connects to the end of planar portion S1 in the Y1 direction via an arc-shaped curved surface. When viewed in the Y1 direction, planar portion S6 extends clockwise relative to planar portion S1.

[0182] The inclined surface S7 smoothly connects to the end of the planar portion S6 opposite the planar portion S1 via an arc-shaped curved surface. The inclined surface S7 is an inclined surface that tilts clockwise as it advances in the Y1 direction. The inclined surface S7 has approximately the same inclination as the spiral portion S3, which is opposite in the Y direction. For example, the inclined surface S7 may also be a spiral surface similar to the spiral portion S3.

[0183] The end portion of the inclined surface portion S7 in the Y1 direction is smoothly connected to the surface of the base material 35 a in the Y2 direction via an arc-shaped curved surface.

[0184] like Figure 11A 、 Figure 11B As shown, the rib 40 protrudes outward from the outer surface 35j. In this embodiment, the rib 40 is a flat plate parallel to the radial direction and the axial direction of the rotating member 35. The rib 40 extends in the axial direction of the main body 35b, that is, in the Y direction.

[0185] In this embodiment, the rib 40 is a protrusion on the outer surface 35j and has a thickness less than the thickness of the main body 35b (the distance between the outer surface 35j and the inner surface 35d). The height of the rib 40 from the outer surface 35j is greater than the thickness of the main body 35b.

[0186] The Y1-direction end of the rib 40 is connected to the Y2-direction surface of the base material 35a. The rib 40 is provided across the base material 35a and the main body 35b. In particular, when viewed from the radial direction of the main body 35b, the rib 40 and the spiral portion S3 intersect and span the through-hole 35e. However, the Y1-direction end surface of the rib 40 above the through-hole 35e is formed at a height that does not interfere with the front end of the first engaging portion 36 passing through the through-hole 35e.

[0187] like Figure 10 As shown, when viewed from the Y1 direction, the rib 40 also spans the gap between the outer surface 35j and the inner wall of the hole 35i to connect the main body 35b and the base material 35a.

[0188] like Figure 11A As shown, the front end of the rib 40 in the Y2 direction protrudes in the Y2 direction from the flat surface portion S2. Figure 11A In the illustrated example, the front end of the rib 40 in the Y2 direction reaches the vicinity of the front end of the base material 35 a in the Y2 direction.

[0189] An inclined portion 40 a that moves away from the outer surface 35 j as it advances in the Y1 direction is formed at a front end portion of the rib 40 in the Y2 direction.

[0190] like Figure 11A 、 Figure 11BAs shown, the rib 41 protrudes outward from the outer surface 35j. In this embodiment, the rib 41 is a flat plate parallel to the radial direction and the axial direction of the rotating member 35. The rib 41 extends in the axial direction of the main body 35b, that is, in the Y direction.

[0191] The end portion of the rib 41 in the Y1 direction is connected to the surface of the base material 35a in the Y2 direction. The rib 41 is provided across the base material 35a and the main body 35b.

[0192] In this embodiment, the position of the front end of the rib 41 in the Y2 direction is the same as that of the rib 40. An inclined portion 41a similar to the inclined portion 40a of the rib 40 is formed at the front end of the rib 41 in the Y2 direction.

[0193] The rib 41 is separated from the rib 40 in the circumferential direction of the main body 35b. In the present embodiment, the rib 41 is provided near the plane portion S1 and at a position offset counterclockwise relative to the plane portion S1 when viewed from the Y1 direction.

[0194] exist Figure 10 In the illustrated example, the ribs 40 and 41 are formed at positions opposing each other in the radial direction of the main body portion 35 b.

[0195] like Figure 11A 、 Figure 11B As shown in FIG. 1 , a guide wall 35h is provided on the surface of the base material 35a in the Y1 direction of the rotating member 35. The guide wall 35h is provided outside the hole 35i when viewed from the Y2 direction.

[0196] The guide wall 35h includes a side wall portion 35h1 protruding from the base material 35a in the Y1 direction, and a rear wall portion 35h2 protruding from an end portion of the side wall portion in the Y1 direction in the X2 direction.

[0197] The gap between the side wall portion 35h1 and the base material 35a is larger than the thickness of the guide flange 39c of the operation member 39 in the Y direction. The distance from the central axis of the main body portion 35b to the rear wall portion 35h2 is larger than the distance from the central axis O (refer to Figure 9 ) is the center of the guide flange 39c, and the rotation radius is long.

[0198] A guide groove 35 g into which the guide flange 39 c of the operation member 39 can be inserted and which is rotatable about the central axis O is formed between the guide wall 35 h and the base material 35 a .

[0199] like Figure 9 、 Figure 10 As shown, in the operating mechanism 34E, the linear motion member 37 is held adjacent to the fixed portion 34Af and is inserted into the inner hole 35c of the main body portion 35b (see Figure 10The first engaging portion 36 is inserted into the inner side of the through-hole 35e. The guide flange 39c of the operating member 39 is inserted into the guide groove 35g, and the front end of the cylindrical portion 39a in the Y2 direction is engaged with the end of the linear motion member 37 in the Y1 direction. The rod 39b of the operating member 39 is adjacent to the Y1 direction side of the base 35a of the rotating member 35. The operating member 39 is prevented from falling out in the Y direction in the guide groove 35g.

[0200] Since the linear member 37 is fixed by the shoulder screw 38 (refer to Figure 10 ) is supported so as to be rotatable about the central axis O. Therefore, when the operating member 39 rotates about the central axis O, the linear motion member 37 rotates together with the operating member 39 in the main body portion 35b.

[0201] The operation of image forming apparatus 100 will be described.

[0202] First, the image forming operation of the image forming apparatus 100 will be briefly described.

[0203] like Figure 1 As shown, in the image forming apparatus 100, each exposure unit 26 is mounted on the base 11 in the printing unit 3 so that the exposure head 33 is in contact with the base 11. At the contact position, the focal position of the lens is aligned with the surface of the photosensitive drum 7.

[0204] Image formation is initiated by operating the control panel 1 or by an external signal. Image information is sent to the printer 3 by the scanner 2 after scanning the copy object, or is sent to the printer 3 from an external source. Based on the operation of the control panel 1 or an external signal, and based on a control signal generated by the control unit 6, the printer 3 feeds the sheet P in the sheet feeder 4 or the manual unit 10 to the registration roller 24.

[0205] When an operation input for image formation is performed from the control panel 1 , the control unit 6 performs control to start feeding the sheet P and image formation, for example.

[0206] Each exposure unit 26 exposes the photosensitive drums 7 of the image forming units 25Y, 25M, 25C, and 25K based on the image information corresponding to each color sent from the control unit 6, thereby forming an electrostatic latent image corresponding to the image information. Each electrostatic latent image is developed by the developer 8. As a result, a toner image corresponding to the electrostatic latent image is formed on the surface of each photosensitive drum 7.

[0207] The toner images are primarily transferred to the intermediate transfer belt 27 by the transfer rollers. The toner images are sequentially superimposed so as not to cause color deviation as the intermediate transfer belt 27 moves, and are then sent to the transfer section 28.

[0208] The sheet P is fed from the registration rollers 24 to the transfer section 28 . The toner image reaching the transfer section 28 is secondarily transferred to the sheet P. The secondarily transferred toner image is fixed to the sheet P by the fixing device 29 . Thus, an image is formed on the sheet P.

[0209] In image forming apparatus 100, it is sometimes necessary to pull photosensitive drum unit 25D out of the apparatus for maintenance. In this case, the user operates operating mechanism 34E to move exposure head 33 of exposure section 26 corresponding to the pulled-out image forming section 25 to the separated position, and then pulls out photosensitive drum unit 25D.

[0210] Hereinafter, the operation of the lifting mechanism 34 and the operation mechanism 34E will be described with a focus on the function of the operation mechanism 34E.

[0211] like Figure 6 As shown, when the exposure head 33 is in the contact position, the lifting mechanism 34 is raised relative to the support member 34C in the Z1 direction. In this embodiment, the exposure head 33 connected to the first engaging shaft 34Baa of each second link 34Ba is raised by the action of the link mechanism 34B that raises each second link 34Ba from a nearly horizontal position.

[0212] In order to make the second link 34Ba stand up in the link mechanism 34B, Figure 4 As shown, the engagement axis 34Bbb of the third link 34Bb and the third engagement axis 34Bac of the second link 34Ba only need to be positioned close to each other in the Y direction.

[0213] In the present embodiment, since the engagement shaft 34Bbb is engaged with the support portion 34Cc of the support member 34C, the third engagement shaft 34Bac connected to the first link 34A is moved in the Y2 direction.

[0214] like Figure 6 As shown, when viewed from the Y2 direction, the user rotates the lever 39b of the operating member 39 clockwise to the rotation limit (hereinafter referred to as the raised position) relative to the central axis O. The first link 34A is pulled by the urging member 34D and moves in the Y2 direction.

[0215] In the raised position of the operating member 39, as Figure 9 、 Figure 10 As shown, the first engaging portion 36 is in contact with the plane portion S1 . The first engaging portion 36 is separated from the plane portions S2 and S6 in the Y direction and is located between the plane portions S2 and S6 .

[0216] The first engaging portion 36 presses the flat surface portion S1 along the circumferential direction, but does not press the main body portion 35 b in the Y direction.

[0217] The first link 34A stops at a position where the force in the Y1 direction caused by the pressing force from the spacers 25dF and 25dR applied by the link mechanism 34B to the exposure head 33 is balanced with the pulling force in the Y2 direction applied by the urging member 34D.

[0218] The operation of lowering the exposure head 33 from the contact position to the separated position will be described.

[0219] Figure 12 It is a perspective schematic diagram of the exposure unit and the lifting mechanism in the separated positions in the image forming apparatus according to the embodiment. Figure 13 It is a perspective schematic diagram showing the operating mechanism in the separated position in the image forming apparatus according to the embodiment. Figure 14 It is along Figure 13 Schematic diagram of a cross section of the F14-F14 line.

[0220] like Figure 12 As shown, when viewed from the Y2 direction, the user rotates the lever 39 b of the operating member 39 counterclockwise relative to the central axis O to the rotation limit (hereinafter, lowered position).

[0221] like Figure 13 As shown in FIG. 1 , when viewed from the Y2 direction, the linear motion member 37 rotates counterclockwise along with the rotation of the operation member 39 .

[0222] Since the plurality of protrusions 37d are formed on the outer surface of the linear motion member 37, the contact area between the inner surface 35d of the main body 35b and the outer surface of the linear motion member 37 is reduced compared to a case where the outer surface of the linear motion member 37 is formed of a cylindrical surface, enabling smooth rotation.

[0223] In the raised position, the first engaging portion 36 a, schematically indicated by a two-dot chain line, contacts the flat surface S1. The first engaging portion 36 moves in the circumferential direction (from the bottom to the top in the figure) in conjunction with the rotation of the linear motion member 37, and contacts the spiral portion S3, schematically indicated by a two-dot chain line, as indicated by a first engaging portion 36 b.

[0224] like Figure 11B As shown, as the linear motion member 37 further rotates toward the spiral portion S3, the first engaging portion 36b moves circumferentially along the spiral portion S3, as shown in the blank portion of the figure, and also moves in the Y1 direction. Since the end portion of the linear motion member 37 in the Y1 direction is locked by the shoulder screw 38, the first link 34A moves in the Y1 direction via the shoulder screw 38. The biasing member 34D extends in the Y1 direction in conjunction with the movement of the first link 34A, increasing its elastic restoring force in the Y2 direction.

[0225] The first engaging portion 36 provided on the linear motion member 37 and the linear motion member 37 is urged by the urging member 34D in the Y2 direction away from the substrate 35a. The first engaging portion 36 can press the inner peripheral surface S on the Y2 side, such as the flat portion S2, the spiral portion S3, and the flat portion S4, along the Y2 direction.

[0226] Because the lifting limit of the exposure head 33 in the image forming apparatus 100 is limited by the spacers 25dR and 25dF, the inner circumferential surface S that the first engaging portion 36 presses in the Y2 direction in the image forming apparatus 100 is formed by the spiral portion S3 and the flat portion S4. The spiral portion S3 and the flat portion S4 are examples of a second engaging portion that engages with the first engaging portion 36 in the Y2 direction. The second engaging portion, by engaging with the first engaging portion 36, limits the movement of the linear motion member 37 along the central axis O to a predetermined distance. In particular, the flat portion S4 defines the movement distance of the linear motion member 37 at the separated position.

[0227] The Y2 direction in this embodiment is an example of a first direction away from the substrate.

[0228] The elastic restoring force of the urging member 34D acts on the spiral portion S3 in the Y2 direction via the first engagement portion 36. For example, the force Fb in the Y2 direction acts on the spiral portion S3 from the first engagement portion 36b.

[0229] The vertical component Fb1 and the parallel component Fb2 of the force Fb act on the spiral portion S3. The vertical component Fb1 acts as an external force pulling the spiral portion S3 away from the substrate 35a. The parallel component Fb2 acts as resistance in the direction of movement of the first engaging portion 36b.

[0230] As the linear motion member 37 rotates further, the first engaging portion 36 moves further in the Y1 direction, and as shown by the first engaging portion 36c schematically indicated by the two-dot chain line, the first engaging portion 36 abuts the flat surface portion S4. A force Fc in the Y2 direction acts on the flat surface portion S4 in response to the elastic restoring force of the biasing member 34D, which is greater than when it abuts the spiral portion S3. This force Fc acts as an external force that pulls the flat surface portion S4 away from the base 35a in the Y2 direction.

[0231] When the direct-acting member 37 rotates further, as shown in FIG. Figure 14 As shown, the first engaging portion 36 contacts the flat surface S5, and the operating member 39 reaches the lowered position. Since the first engaging portion 36 is locked to the flat surface S4 in the Y direction, the operating member 39 and the linear motion member 37 remain in the lowered position even if the user releases his hand from the lever 39b.

[0232] In this way, when the operation member 39 moves to the lowered position, the first link 34A moves to the farthest end in the Y1 direction on the support portion 34Cc.

[0233] like Figure 5A 、 Figure 5B As shown in FIG. 1 , the distance in the Y direction between the engagement axis 34Bbb of the third link 34Bb and the third engagement axis 34Bac of the second link 34Ba is increased. Figure 12 As shown in FIG. 1 , each second link 34Ba is moved closer to the horizontal position from the upright state, and the exposure head 33 connected to the first engagement shaft 34Baa of each second link 34Ba is lowered to the separated position.

[0234] The height of the exposure head 33 at the separated position from the bottom surface 34Ca depends on the tilt angle of each second link 34Ba relative to the horizontal plane. The tilt angle of each second link 34Ba corresponds to the movement position of the first link 34A in the Y direction.

[0235] As a factor of error in the movement position of the first link 34A, for example, deformation of the rotating member 35 is mentioned.

[0236] Figure 15 It is a schematic perspective view illustrating the function of a rotating member in the image forming apparatus according to the embodiment.

[0237] The first link 34A reaches its furthest end in the Y1 direction when the first engaging portion 36 is engaged with the flat surface S4. The flat surface S4 defines the position of the first link 34A in the Y direction at the separated position. Since the base 35a is fixed to the side plate of the support member 34C, the position of the base 35a in the Y direction is constant.

[0238] For example, if the flat portion S4 moves in the Y2 direction due to deformation of the main body 35b, the amount of movement becomes a positional error of the first link 34A in the Y direction. In the flat portion S4, even at the point where the force acting on the main body 35b from the first engaging portion 36 through the inner circumferential surface S reaches a maximum value Fc, the deformation of the main body 35b, the spiral portion S3 in the main body 35b, and the flat portion S4 tends to reach a maximum.

[0239] In this embodiment, if Figure 15 As shown, the base member 35a and the outer surface 35j of the main body 35b are connected by ribs 40. The ribs 40 function as reinforcements that increase the rigidity of the main body 35b in the Y direction. The ribs 40 increase the cross-sectional area of ​​the main body 35b parallel to the ZX plane. The ribs 40 also increase the secondary moment of area of ​​the main body 35b parallel to the ZX plane.

[0240] Specifically, the ribs 40 increase the tensile rigidity of the main body 35b in the Y2 direction (see Figure 15 Furthermore, the ribs 40 increase the bending rigidity of the main body 35b in the arrangement direction of the ribs 40 (see arrow A1 in FIG. 1 ). Figure 15 The rib 40 reduces deformation of the spiral portion S3 and the flat portion S4 by reinforcing the main body portion 35b.

[0241] The ribs 40 are connected to the base material 35a fixed to the side plate of the support member 34C and are not easily deformed. Since the main body 35b is integrally fixed to the base material 35a via the ribs 40, deformation of the main body 35b is easily suppressed.

[0242] In particular, since the rib 40 straddles the through-hole 35e and connects the main body 35b and the base 35a in the Y direction, the opening of the through-hole 35e can be prevented from expanding in the Y direction near the rib 40. By suppressing the expansion of the opening of the through-hole 35e, deformation of the spiral portion S3 and the flat portion S4 is also reduced.

[0243] In this embodiment, the rib 40 is located near the flat surface S4. The flat surface S4 is located where the first engaging portion 36 is closest to the substrate 35a on the inner circumferential surface S and where the pulling force from the biasing member 34D is maximized. This arrangement effectively prevents deformation of the main body 35b, particularly any increase in the distance between the spiral portion S3 and the flat surface S4 and the substrate 35a.

[0244] In this embodiment, the rotating member 35 includes ribs 41 in addition to ribs 40. Similar to ribs 40, ribs 41 are formed to be elongated in the Y direction, spanning the outer surface 35j of the main body 35b and the base 35a. This increases the cross-sectional area and the secondary moment of area of ​​the main body 35b. Ribs 41 also increase the tensile and flexural rigidity of the main body 35b compared to a case without ribs 41.

[0245] In particular, in the present embodiment, since the ribs 41 and 40 are provided at positions corresponding to each other with the main body portion 35 b interposed therebetween, the bending rigidity in the opposing direction is significantly improved.

[0246] Since the spiral portion S3 is sandwiched between the ribs 41 and 40 in the circumferential direction of the main body portion 35 b , deformation of the spiral portion S3 between the ribs 41 and 40 is also significantly suppressed.

[0247] In particular, since the rib 41 is provided near the flat surface portion S1 , deformation of the inner peripheral surface S near the flat surface portion S1 can be effectively suppressed.

[0248] The ribs reinforcing the main body 35b are not limited to ribs 40 and 41; an appropriate number of ribs may be provided at appropriate locations. For example, rib 41 may not straddle the through-hole 35e, but may suppress deformation of the inner circumferential surface S near the location where it is positioned. For example, the ribs reinforcing the main body 35b may consist solely of ribs positioned near the inner circumferential surface S and not straddling the through-hole 35e.

[0249] The functions of the ribs 40 and 41 will be described in comparison with a comparative example.

[0250] Figure 16 It is a schematic perspective view showing the operation of a rotating member of a comparative example.

[0251] Figure 16 The rotating member 135 of the comparative example shown has the same structure as the rotating member 35 of the embodiment, except that the ribs 40 and 41 are not provided. When the rotating member 135 is used instead of the rotating member 35 of the operating mechanism 34E of the embodiment, when the operating member 39 is in the lowered position, the force Fc acts on the flat surface S4, similar to the embodiment.

[0252] Since the main body portion 35 b of the comparative example is not reinforced by the ribs 40 and 41 , it is more likely to be deformed by the force Fc than the rotating member 35 .

[0253] For example Figure 16 As indicated by the two-dot chain line, the planar portion S4 and the spiral portion S3 are deformed in the direction away from the substrate 35 a in the Y2 direction by the force Fc.

[0254] In particular, because the deformation of the planar portion S4 in the Y2 direction is significantly greater than that of the rotating member 35, an error in the Y-direction movement of the rotating member 37 and the first link 34A engaged with the rotating member 37 occurs in accordance with the amount of deformation. This movement error represents a deviation from the movement distance specified by the spiral portion S3 and the planar portion S4. Because the amount of descent of the exposure head 33 at the separated position is less than the designed value due to this movement error, the gap between the exposure head 33 and the housing 25A decreases.

[0255] For example, when the photosensitive drum unit 25D is pulled out, there is a possibility that the exposure head 33 and the photosensitive drum unit 25D may interfere with each other.

[0256] For example, when cleaning the exposure head 33 , the clearance through which a cleaning tool can be inserted becomes narrow, and thus there is a possibility that cleaning of the exposure head 33 becomes difficult.

[0257] As described above, the ribs 40 and 41 of the rotating member 35 suppress deformation of the main body 35b and reduce positional error of the flat surface S4 relative to the substrate 35a in the first direction. As a result, the exposure head 33 is prevented from accurately descending to the predetermined separation position.

[0258] For example, when the photosensitive drum unit 25D is pulled out, the exposure head 33 can be prevented from interfering with the photosensitive drum unit 25D.

[0259] For example, when cleaning the exposure head 33 , a gap for inserting a cleaning tool can be ensured, so that cleaning of the exposure head 33 becomes easy.

[0260] As described above, according to the image forming apparatus 100 of this embodiment, the rotating member 35 includes the ribs 40 and 41 , so that deformation of the main body 35 b can be suppressed, and the height of the exposure head 33 at the separated position can be suppressed.

[0261] According to the present embodiment, the photosensitive drum unit 25D at the separated position of the exposure head 33 can be easily pulled out, and the exposure head 33 can be easily cleaned.

[0262] According to the present embodiment, it is possible to provide the image forming apparatus 100 in which maintenance of the photosensitive drum unit 25D and the exposure head 33 is easy.

[0263] Modifications of the above-described embodiments will be described below.

[0264] In the embodiment, the rotating member 35 has been described as having the ribs 40 and 41. Since the ribs 40 and 41 can reinforce the main body 35b, the rotating member 35 may not have one of the ribs 40 and 41 if the required strength of the main body 35b is obtained.

[0265] In the embodiment, the ribs 40 and 41 are described as being thinner and thicker than the plate thickness of the main body 35b. However, if the required reinforcement strength and formability can be achieved, the ribs 40 and 41 may be formed thicker or thinner than the plate thickness of the main body 35b.

[0266] The ribs 40 and 41 include a rib structure in resin molding, and also include protrusions in a broader sense than the rib structure in resin molding.

[0267] For example, the front end portion of the rib 40 in the Y2 direction may have a curved shape instead of the inclined portion 40 a or may have an angular shape.

[0268] For example, the ribs 40 and 41 do not need to be plate-shaped. For example, the ribs 40 and 41 may be triangular protrusions whose thickness decreases as they advance in the Y2 direction, when viewed from the radial direction. For example, the cross-sectional shape of the ribs 40 and 41 parallel to the ZX plane is not limited to a rectangle or a trapezoid, but may also be a semicircle, a parabola, or the like.

[0269] For example, when the cross-sectional shape of the outer surface 35 j of the main body portion 35 b parallel to the ZX plane is formed into a polygonal shape, the ribs 40 and 41 may be formed of thick-walled portions in the corner portions that bulge outward.

[0270] In the embodiment, the ribs 40 and 41 are described as being disposed in opposing positions, sandwiching the main body 35b. The spacing between the ribs 40 and 41 is not particularly limited as long as the desired reinforcement strength and formability are achieved. For example, the ribs 40 and 41 may be formed close together in the circumferential direction. In this case, connecting ribs may be formed between adjacent ribs 40 and 41 to connect them in the circumferential direction.

[0271] In this way, the reinforcing effect of a plurality of ribs arranged in parallel or a plurality of ribs connected to each other in parallel is further increased compared to a single rib.

[0272] In the embodiment, the rotating member 35 is described as having ribs 40 and 41 extending in the axial direction of the main body 35b. If the desired reinforcement strength and formability can be achieved, the ribs 40 and 41 may also extend in a direction oblique to the axial direction of the main body 35b. For example, the ribs 40 and 41 may be formed in a serrated shape as they extend in the Y2 direction. For example, the ribs 40 and 41 may also be provided along the inner circumferential surface S of the through-hole 35e.

[0273] In the embodiment, the main body 35b is described as being cylindrical. However, the main body is not limited to being cylindrical. For example, the main body may be a flat plate, an inwardly curved plate formed in a cylindrical shape, or the like.

[0274] In the embodiment, the rotating member 35, the first engaging portion 36, and the linear motion member 37 are described as being used in the lifting mechanism 34 for lifting and lowering the exposure head 33. The lifting mechanism is not limited to a lifting mechanism for lifting and lowering the exposure head 33. For example, the lifting mechanism may also be a lifting mechanism for lifting and lowering the intermediate transfer belt unit including the intermediate transfer belt 27.

[0275] In the embodiment, the lifting mechanism 34 is described as moving the exposure head 33 up and down in the Z direction. If the optical axis of the exposure head 33 is not aligned with a vertical plane, the lifting mechanism 34 can also be moved in an appropriate direction corresponding to the optical axis of the exposure head 33. For example, the optical axis of the exposure head 33 can also be aligned with a horizontal plane. In this case, the rotating member 35, the first engaging portion 36, and the linear motion member 37 can also function as a horizontal movement mechanism.

[0276] According to at least one embodiment described above, an image forming device that is easy to maintain the photosensitive drum unit and the exposure head can be provided due to the presence of an operating mechanism, the operating mechanism comprising: a direct-acting member having a first engaging portion and moving along an axis extending in a first direction; a rotating member having a second engaging portion that engages with the first engaging portion in the first direction, and limiting the amount of movement along the axis of the direct-acting member to a predetermined moving distance through the second engaging portion; and ribs that reinforce the rotating member in order to reduce deformation of the second engaging portion and suppress errors in the amount of movement relative to the moving distance.

[0277] Although several embodiments have been described, these embodiments are provided for illustrative purposes only and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways and can be omitted, replaced, or modified without departing from the scope of the invention. These embodiments and their variations are included within the scope and spirit of the invention and are also included within the invention described in the claims and their equivalents.

Claims

1. An operating mechanism comprising: a linear motion member having a first engaging portion and moving along an axis extending in a first direction; a rotating member having a second engaging portion, the second engaging portion having a length in the first direction and in a circumferential direction around the axis and engaging with the first engaging portion in the first direction, the rotating member holding the linear motion member so as to be rotatable around the axis and movable in a direction along the axis when the first engaging portion and the second engaging portion are engaged, and limiting the amount of movement of the linear motion member along the axis to a predetermined distance by the second engaging portion; a rib provided on the rotating member to reinforce the rotating member so as to reduce deformation of the second engaging portion and suppress an error in the movement amount relative to the movement distance; as well as An operating member causes the linear motion member to rotate about the axis, The rotating member includes a main body portion having the second engaging portion formed thereon and a base material connected to the main body portion. The first engaging portion is urged in a first direction away from the substrate and is capable of pressing the second engaging portion in the first direction. The rib extends in the first direction.

2. The operating mechanism according to claim 1, wherein: The rib is provided across the base material and the main body.

3. The operating mechanism according to claim 1, wherein: The second engaging portion is formed on the inner peripheral surface of the through hole opened in the main body. The rib is arranged to straddle the through hole.

4. The operating mechanism according to claim 3, wherein: The main body is cylindrical with a cylindrical inner surface. The through hole opens in the radial direction of the main body. The first direction is the axial direction of the main body.

5. The operating mechanism according to claim 1, wherein: In the second engaging portion, the rib is provided near a position where the first engaging portion is closest to the base material.

6. The operating mechanism according to claim 4, wherein: The second engaging portion includes a spiral surface that spirals in the axial direction. The linear motion member is supported on the inner surface so as to be rotatable in the circumferential direction and is movable in the axial direction along the second engagement portion when rotating.

7. An image forming apparatus comprising: Photosensitive drum, used to carry the electrostatic latent image; an exposure head for performing exposure in order to draw an electrostatic latent image on the photosensitive drum; and The lifting mechanism includes the operating mechanism according to claim 1, wherein the lifting mechanism is locked to the direct-acting member in a manner linked to the direct-acting member of the operating mechanism, and supports the exposure head so that it can move in the second direction in which the exposure head approaches the photosensitive drum in accordance with the moving distance of the direct-acting member in the direction along the axis.

8. The image forming apparatus according to claim 7, wherein: The rib suppresses deformation of the second engaging portion when the exposure head is moved in a direction away from the photosensitive drum.

9. The image forming apparatus according to claim 7, wherein: The lifting mechanism comprises: a first connecting rod, which moves in the first direction in conjunction with the movement of the linear motion member in the first direction; as well as The link mechanism converts the displacement of the first link in the first direction into the displacement in the second direction, and supports the exposure head so as to be movable in the second direction.

Images