Image forming apparatus

Abstract

To provide an image forming apparatus capable of preventing a cleaning member for cleaning an exposure part from being erroneously inserted into a cooling space formed between a developing part and a supporting part while suppressing the lowering of the cooling efficiency of the developing part.SOLUTION: A developing duct rib 900 is arranged in a developing duct 1051 of a developing unit 24. The size of the developing duct 1051 is larger than the size of the cleaning member in order to cause a sufficient amount of air for cooling the developing unit 24 to flow through the cooling space. For that reason, in the case where the user erroneously inserts the cleaning member into the developing duct 1051, the sliding portion 601 of the cleaning member abuts against the developing duct rib 900, so that the cleaning member does not enter the developing duct 1051. As a result, even when the size of the developing duct 1051 is not made smaller than the size of the cleaning member, by providing the developing duct 1051 with the developing duct ribs 900, it is possible to realize prevention of erroneous insertion of the cleaning member into the cooling space while suppressing a lowering in cooling efficiency of the developing unit 24.SELECTED DRAWING: Figure 19

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus such as a printer, a copying machine, a facsimile machine, or a multifunction machine. [Background technology]

[0002] In an image forming apparatus, an electrostatic latent image is formed on a charged photosensitive drum by an exposure unit having multiple light-emitting elements, such as LEDs or organic EL elements, arranged along the rotational axis of the photosensitive drum. The exposure unit has a lens array with multiple lenses arranged along the rotational axis (longitudinal direction) of the photosensitive drum to focus light emitted from each light-emitting element onto the surface of the photosensitive drum. Because the focal length of this lens array is extremely short and the exposure unit is located close to the photosensitive drum, foreign matter such as toner and paper dust easily adheres to the lens array. Therefore, a cleaning member has been proposed that allows a user to clean the lens array by inserting it longitudinally from outside the image forming apparatus (Patent Document 1).

[0003] The exposure unit is located close to the development unit, which develops the electrostatic latent image formed on the photosensitive drum into a toner image, and heat generated by the exposure unit can affect the toner contained in the developer. Therefore, to reduce the impact of heat on the toner, the development unit is cooled by supplying air from outside the image forming apparatus (Patent Document 2). In the device described in Patent Document 2, the development unit is supported on a cartridge tray so that it can be inserted and removed longitudinally, and a cooling space is formed between the development unit and the cartridge tray through which air supplied from outside the device body passes. The image forming apparatus also has an inner door that can be opened and closed relative to the device body, and a connection port (duct) is provided inside the inner door to allow external air to pass through the cooling space. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-3113 [Patent Document 2] Japanese Patent Publication No. 2022-156782 Summary of the Invention [Problem to be solved by the invention]

[0005] The cleaning member is provided so that it can be inserted and removed along an insertion guide when the inner door is open. When the inner door is open, both the cooling space and the insertion guide are exposed. This raises the risk of a user accidentally inserting the cleaning member into the cooling space. One way to prevent the cleaning member from being erroneously inserted into the cooling space is to make the size (cross-sectional area) of the cooling space smaller than the size (cross-sectional area) of the cleaning member. However, reducing the size of the cooling space reduces the cooling efficiency of the development unit, making this approach difficult to adopt.

[0006] The present invention has been made in consideration of the above-mentioned problems, and aims to provide an image forming apparatus that can prevent the incorrect insertion of a cleaning member for cleaning the exposure section into the cooling space formed between the development section and the support section, while suppressing a decrease in the cooling efficiency of the development section. [Means for solving the problem]

[0007] an exposure unit that exposes the surface of the photosensitive member to light to form an electrostatic latent image; a development unit that develops the electrostatic latent image on the photosensitive member into a toner image; a support unit that supports the development unit and forms a space between the development unit and the support unit, and a guide unit that is provided at one end of the lens array in the direction of the rotation axis and that guides a cleaning member having a cleaning unit for cleaning the lens array from outside the device body to the lens array along the direction of the rotation axis; a development duct that is provided at the one end of the space in the direction of the rotation axis and that allows air to flow into the space from outside the device body; and a regulating unit that regulates the cleaning member from entering the development duct from outside the device body. [Effects of the Invention]

[0008] According to the present invention, it is possible to prevent the incorrect insertion of a cleaning member for cleaning the exposure section into the cooling space formed between the development section and the support section while suppressing a decrease in the cooling efficiency of the development section. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is an external perspective view showing an image forming apparatus according to an embodiment of the present invention; [Figure 2] FIG. 1 is a schematic diagram illustrating a configuration of an image forming apparatus. [Figure 3] FIG. 4 is a schematic diagram showing the image forming apparatus when the developing sleeve and the exposure unit are in the separated position. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. 4 is a perspective view showing the bottom surface of the exposure unit. [Figure 7] FIG. [Figure 8]FIG. 4 is an enlarged view showing the front cover and inner door in an open state. [Figure 9] FIG. 4 is an enlarged view showing the state in which the drum unit is removed. [Figure 10] FIG. 4 is an enlarged view showing a state in which the development unit is removed. [Figure 11] FIG. 2 is a cross-sectional view showing the drum unit, the developing unit, the exposure unit, and the cartridge tray. [Figure 12] FIG. [Figure 13] FIG. 4 is a perspective view showing the cartridge tray with the inner door open. [Figure 14] FIG. 10 is a side view showing the cartridge tray with the inner door closed. [Figure 15] FIG. 4 is a side view showing the cartridge tray with the inner door open. [Figure 16] 1A and 1B are diagrams for explaining the contact and separation mechanism of the exposure unit, in which FIG. 1A shows the exposure unit at the exposure position, and FIG. 1B shows the exposure unit at the separation position. [Figure 17] FIG. [Figure 18] FIG. [Figure 19] FIG. 10 is a front view illustrating a development duct rib. [Figure 20] FIG. 10 is a side cross-sectional view for explaining a development duct rib. [Figure 21] FIG. 10 is a schematic diagram showing another embodiment of the development duct rib. DETAILED DESCRIPTION OF THE INVENTION

[0010] [Image forming equipment] The present embodiment will be described below. First, an overview of the image forming apparatus of the present embodiment will be described with reference to FIGS. 1 to 3. As shown in FIG. 1, the image forming apparatus 100 of the present embodiment is a so-called internal discharge type image forming apparatus. That is, the image forming apparatus 100 includes an apparatus main body 100A and an original reading device 200 that reads image information from an original, and an output tray 21 that stacks sheets S (recording materials) discharged from the apparatus main body 100A is formed between the apparatus main body 100A and the original reading device 200. The image forming apparatus 100 forms a toner image on the sheet S in accordance with an image signal sent from the original reading device 200 or an external device (not shown) such as a personal computer.

[0011] An operation unit 46 having a display unit capable of displaying various information and keys for inputting various information in response to user operation is disposed on the front side of the device main body 100A. In this specification, the side from which a user inserts and removes developing units and cleaning members (described below) that are removably mounted in the device main body 100A from the outside of the device main body 100A is referred to as the "front (front face)," and the opposite side is referred to as the "rear (back face)." In addition, the left side when viewing the image forming device 100 from the front is referred to as the "left," and the right side when viewing the image forming device 100 from the front is referred to as the "right."

[0012] Apparatus main body 100A is made up of a front plate provided on the front side of image forming apparatus 100, a rear plate provided on the rear side that supports each unit together with the front plate, stays connecting these front and rear plates, pillars supporting the front plate, and other metal plates, and is covered by an exterior cover that constitutes the exterior of image forming apparatus 100. As exterior covers, a front cover 101, multiple cassette covers 103, and an upper front cover 104 are arranged on the front side. In addition, side covers are arranged on the left and right side sides, and a rear cover is arranged on the rear side.

[0013] 2 and 3 includes four image forming units 1Y, 1M, 1C, and 1K that form toner images of four colors: yellow (Y), magenta (M), cyan (C), and black (K). Note that the configurations of the image forming units 1Y, 1M, 1C, and 1K that form toner images of each color are almost the same, so in FIGS. 2 and 3, only the magenta image forming unit 1M is given a reference numeral, and the image forming unit 1M will be used as an example for explanation.

[0014] The image forming section 1M has two units, a drum unit 23 and a developing unit 24 (see FIG. 3). The drum unit 23 and the developing unit 24 are supported by a cartridge tray 30 and are provided so as to be insertable into and removable from the cartridge tray 30 from the front side of the apparatus main body 100A so as to be guided in the direction of the rotation axis (longitudinal direction) of the photosensitive drum 2 that rotates around a rotation axis. The drum unit 23 has the photosensitive drum 2 as a photosensitive member, a charging roller 3 that charges the photosensitive drum 2, and a drum cleaner unit (not shown).

[0015] The developing unit 24 as a developing section is disposed in a developing container that contains a developer containing toner, and includes a developing sleeve 5 that supplies toner to the photosensitive drum 2 to form a toner image, and a conveying screw 7 that conveys the toner while stirring it. Between the drum unit 23 and the developing unit 24 in the rotation direction of the photosensitive drum 2, an exposure unit 4 that exposes the surface of the photosensitive drum 2 to light to form an electrostatic latent image is disposed. The exposure unit 4 as an exposure section is supported by the cartridge tray 30 so as to be disposed between the drum unit 23 and the developing unit 24.

[0016] An intermediate transfer belt unit 8 is disposed above the image forming stations 1Y to 1K. The intermediate transfer belt unit 8 has four primary transfer rollers 6 disposed opposite the photosensitive drums 2 of each color, and one endless intermediate transfer belt 9. Toner bottles 22Y to 22K containing replenishment toner to be supplied to the developing units 24 are provided above the intermediate transfer belt unit 8 so as to be detachable from a toner supply mechanism (not shown). The toner supply mechanism supplies the appropriate amount of toner from the toner bottles 22Y to 22K to each developing unit 24 of the corresponding image forming stations 1Y to 1K at the appropriate time. Sheet cassettes 12A and 12B containing sheets S are disposed below the image forming stations 1Y to 1K.

[0017] <Image formation process> Next, the image forming process on the sheet S in the image forming apparatus 100 will be described. In each of the image forming units 1Y to 1K, the surface of the photosensitive drum 2, which is driven to rotate by a motor (not shown), is uniformly charged by a charging roller 3 pressed against the photosensitive drum 2. Thereafter, an exposure unit 4, which is driven based on a signal of image information, irradiates the surface of the photosensitive drum 2 with light, and an electrostatic latent image is formed on the surface of the photosensitive drum 2. The electrostatic latent image formed on the photosensitive drum 1 is developed into a toner image by a developing unit 24. The developing unit 24 develops the electrostatic latent image with toner contained in a developer, and forms a toner image on the photosensitive drum 1.

[0018] In the developing unit 24, a high voltage is applied to the developing sleeve 5, and the toner, which is charged by the stirring of the conveying screw 7, is uniformly coated on the surface of the developing sleeve 5. The conveying screw 7 is rotated at a relatively high speed compared to the rotational speed of the developing sleeve 5 and the photosensitive drum 2, and as a result, the toner is evenly coated on the surface of the developing sleeve 5.

[0019] The toner image formed on the photosensitive drum 2 (photoconductor) is primarily transferred from the photosensitive drum 2 to the intermediate transfer belt 9 by applying a primary transfer voltage to a primary transfer roller 6 disposed opposite the image forming units 1Y to 1K with the intermediate transfer belt 9 interposed therebetween. A drum cleaner unit (not shown) collects residual toner remaining on the photosensitive drum 2 after the primary transfer.

[0020] Inside the apparatus main body 100A of the image forming apparatus 100, a sheet transport path for transporting the sheet S from bottom to top is provided on the right side. Arranged on this sheet transport path from bottom to top are a supply roller pair 13, a registration roller pair 15, a secondary transfer outer roller 16, a fixing unit 19, and a discharge roller pair 20. The secondary transfer outer roller 16 abuts against the secondary transfer inner roller 10, which is arranged inside the intermediate transfer belt 9, with a predetermined pressure across the intermediate transfer belt 9, thereby forming a secondary transfer nip portion 17.

[0021] Sheets S stored in sheet cassettes 12A and 12B are supplied one by one from either sheet cassette 12A or 12B to a sheet conveying path by driving supply roller pair 13 at a predetermined control timing. Sheet S supplied by supply roller pair 13 is conveyed to registration roller pair 15 arranged midway along the conveying path. Then, registration roller pair 15 corrects skew and timing of sheet S, and sends sheet S to secondary transfer nip portion 17. Secondary transfer nip portion 17 is formed by secondary transfer inner roller 10 and secondary transfer outer roller 16 that face each other across intermediate transfer belt 9, and is a nip portion that transfers a toner image from intermediate transfer belt 9 onto sheet S by applying a predetermined pressure and secondary transfer voltage.

[0022] The image formation processes for each color, which are processed in parallel by the image forming units 1Y to 1K for each color described above, are performed in a timed manner to sequentially superimpose the image onto the toner image of the color that was primarily transferred onto the intermediate transfer belt 9 upstream in the movement direction. As a result, a full-color toner image is formed on the intermediate transfer belt 9 and is transported to the secondary transfer nip portion 17. At the secondary transfer nip portion 17, the timing of the sheet S and the full-color toner image coincides, and secondary transfer is performed in which the toner image is transferred from the intermediate transfer belt 9 to the sheet S. The sheet S is then transported to the fuser 19, where the toner image is fixed to the sheet S by applying heat and pressure. After passing through the fuser 19, the sheet S is transported to the discharge roller pair 20 and discharged onto the discharge tray 21 by the discharge roller pair 20.

[0023] In this embodiment, the drum unit 23 and the developing unit 24 deteriorate due to repeated image formation processes and require replacement or maintenance. The drum unit 23 and the developing unit 24 are in the form of cartridges so that the user can easily insert and remove them from the apparatus main body 100A for replacement or maintenance. Figure 3 shows the arrangement of the drum unit 23, the developing unit 24, and the exposure unit 4 when inserting and removing the drum unit 23 and the developing unit 24.

[0024] 3, when inserting or removing the drum unit 23 or the developing unit 24, the developing unit 24 and the exposure unit 4 are separated from the drum unit 23, which differs from the state shown in FIG. 2. This is because if the developing unit 24 and the exposure unit 4 were positioned close to the photosensitive drum 2 when inserting or removing the drum unit 23 or the developing unit 24, dynamic interference during insertion or removal of the drum unit 23 or the developing unit 24 could damage the units or make it impossible to remove them. For this reason, the user is allowed to separate the developing unit 24 and the exposure unit 4 before inserting or removing the drum unit 23 or the developing unit 24.

[0025] <Exposure unit> Next, the exposure unit 4 will be described with reference to Fig. 3 and Fig. 4 to Fig. 6. As shown in Fig. 4, the exposure unit 4 has a mounting substrate 50, a plurality of light-emitting elements 51 arranged in the longitudinal direction on one surface of the mounting substrate 50, and a lens array 52 in which a plurality of lenses that transmit light emitted from the light-emitting elements 51 are arranged. The light-emitting elements 51 are, for example, light-emitting diodes (Light Emitting Diodes) or organic electroluminescence (EL) elements. The lens array 52 has a plurality of lenses arranged in the direction in which the light-emitting elements 51 are arranged.

[0026] The mounting substrate 50 and the lens array 52 have a plurality of light-emitting elements 51 and a plurality of lenses arranged thereon, respectively, across the exposure range in the direction of the rotation axis of the photosensitive drum 2. Therefore, as shown in FIG. 5 , the mounting substrate 50 and the lens array 52 are formed in a shape that extends along the direction of the rotation axis of the photosensitive drum 2. The mounting substrate 50 and the lens array 52 are held in place by being adhered to a housing 54 with high precision using an adhesive. The housing 54 is required to have high rigidity, and in this embodiment, a metal plate such as a galvanized steel plate or a cold-rolled steel plate bent into a substantially U-shaped cross section is used. The lens array 52 and the mounting substrate 50 are inserted into the housing 54 in order from the open side of the U and fixed with an adhesive.

[0027] The housing 54 further has a housing support member 55 formed in a substantially U-shaped cross section, which is provided integrally with the housing 54 on the side of the U-shaped opening. As shown in Fig. 6, an opening 55A that communicates between the inside and outside of the housing support member 55 is formed in the bottom of the housing support member 55 at a position facing the back surface opposite the front surface of the mounting substrate 50 in each housing 54. As described above, the exposure unit 4 is configured as an integrated head unit by the mounting substrate 50 on which the plurality of light-emitting elements 51 are mounted, the lens array 52 in which the plurality of lenses are arranged in parallel, the housing 54, and the housing support member 55.

[0028] Next, the insertion and removal of the drum unit 23 and the developing unit 24 into the apparatus main body 100A will be described with reference to Figures 7 to 10. As shown in Figure 7, the image forming apparatus 100 is equipped with inner doors 102Y, 102M, 102C, and 102K (hereinafter collectively referred to as "inner door 102") that cover the front sides of both the drum unit 23 and the developing unit 24 mounted in the apparatus main body 100A. The inner door 102 is a necessary member for protecting the drum unit 23, the developing unit 24, and the exposure unit 4, and for making it difficult for the photosensitive drum 2 to be exposed to light outside the image formation process, and is disposed in a position facing the front of the units for each color so as to be able to open and close.

[0029] As shown in FIGS. 8 to 10 , one end of the inner door 102 is fixed to the front side of the cartridge tray 30 by a hinge, and the inner door 102 is rotatable relative to the cartridge tray 30 by the hinge. The developing unit 24 and the exposure unit 4 are provided so as to be able to approach and separate from the drum unit 23 by a later-described approach / separation mechanism that operates in conjunction with the opening and closing of the inner door 102. The developing unit 24 moves between a developing position where it is close to the photosensitive drum 2 and can develop an electrostatic latent image, and a spaced position away from the photosensitive drum 2 for maintenance such as cleaning. The exposure unit 4 moves between an exposure position where it is close to the photosensitive drum 2 and can expose the photosensitive drum 2, and a spaced position away from the photosensitive drum 2 where it is not exposed to light. Note that FIGS. 8 to 10 show a state in which only the inner door 102K, which opens and closes to insert and remove the drum unit 23 and developing unit 24 provided in the black image forming unit 1K, is open.

[0030] A front cover 101 is provided at the front side of the image forming apparatus 100 so as to be able to open and close freely. One end of the front cover 101 is fixed to the front side of the apparatus body 100A of the image forming apparatus 100 by a hinge, and the front cover 101 is rotatable relative to the apparatus body 100A of the image forming apparatus 100 by the hinge. The front cover 101 is provided in front of the inner door 102 in the direction of the rotation axis of the photosensitive drum 2. The front cover 101 is an exterior cover that constitutes the external appearance of the image forming apparatus 100, covering the entirety of the multiple inner doors 102 lined up in the left-right direction when closed as shown in FIG.

[0031] 8, the front cover 101 is provided with a front door duct 41 for passing air outside the apparatus main body 100A to each developing unit 24. The front door duct 41 is provided on a second surface (back surface) of the front cover 101 opposite a first surface (front surface) that constitutes part of the exterior of the image forming apparatus 100, and extends in the left-right direction, which is the arrangement direction of the developing units 24. The front door duct 41 has openings 41a at positions corresponding to the developing units 24 of each color. The openings 41a of the front door duct 41 are provided at a position facing the inner door duct 1021 of the inner door 102 in the direction of the rotation axis of the photosensitive drum 2, and communicate with the inner door duct 1021 of the inner door 102 when the front cover 101 is closed.

[0032] The user replaces the drum unit 23 or the developing unit 24 in the following procedure. The user opens the front cover 101 as shown in FIG. 7, and then opens the inner door 102 as shown in FIG. 8, thereby removing the drum unit 23 from the apparatus main body 100A with the developing unit 24 spaced apart from the photosensitive drum 2 (see FIG. 9). Alternatively, the user can remove the developing unit 24 from the apparatus main body 100A with the developing unit 24 spaced apart from the photosensitive drum 2 (see FIG. 10). The user then inserts a new drum unit 23 or developing unit 24, closes the inner door 102, and then closes the front cover 101, thereby completing the replacement of the drum unit 23 or developing unit 24.

[0033] <Developing unit contact / separation mechanism> The developing unit 24 is brought into contact with and separated from the drum unit 23 by a contact / separation mechanism that operates in conjunction with the opening and closing of the inner door 102. The contact / separation mechanism of the developing unit 24 will be described with reference to FIGS. 11 to 15. As described above, the developing unit 24 and the exposure unit 4 are supported by the cartridge tray 30. The cartridge tray 30 is provided for each of the image forming sections 1Y to 1K (see FIG. 2), and supports the drum unit 23 and developing unit 24 so that they can be inserted and removed along the rotation axis direction of the photosensitive drum 2.

[0034] 11, 12 or 13, the cartridge tray 30 has a developer support member 301 that supports and guides the insertion and removal of the developing unit 24 along the rotational axis direction of the photosensitive drum 2, and a drum support member 302 that supports and guides the drum unit 23 along the axis direction of the photosensitive drum 2. The developer support member 301 as a support portion is provided to extend in the rotational axis direction of the photosensitive drum 2 so as to guide and support the developing unit 24 along the rotational axis direction of the photosensitive drum 2. The drum support member 302 is provided to extend in the rotational axis direction of the photosensitive drum 2 so as to guide and support the drum unit 23 along the rotational axis direction of the photosensitive drum 2.

[0035] 11 and 12, a portion of the cartridge tray 30 is disposed directly below the developing unit 24. Between the developing support member 301 and the developing unit 24, a cooling space 310 is formed through which air supplied from outside the apparatus main body 100A can flow in order to cool the developing unit 24. As will be described in detail later, an opening at one longitudinal end (front side) of the cooling space 310 communicates with a developing duct 1051 (see FIGS. 18 and 19) of a developing duct portion 105 provided in the developing unit 24, thereby allowing external air supplied from an inner door duct 1021 of the inner door 102 to flow in.

[0036] As shown in FIGS. 14 and 15, a developer support member 301, a developer pressure piece (front) 32, a developer pressure piece (rear) 33, and a developer stay link 34 are provided on the cartridge tray 30. The developer pressure piece (front) 32 and the developer pressure piece (rear) 33 are fixed to the developer support member 301 and hold and press the developer unit 24 toward the photosensitive drum 2. A developer stay link 34 engaged with an inner door 102 is fixed to the front end of the developer support member 301. The inner door 102 has a link engagement portion 102B that engages with the developer stay link 34, which is located closer to the end than the rotation shaft 102A. Therefore, as the inner door 102 rotates, the door moves in the direction of rotation along a circular locus whose radius is the distance between the rotation shaft 102A and the link engagement portion 102B.

[0037] That is, as shown in FIG. 15, opening the inner door 102 causes the link engagement portion 102B to also rotate and move toward the rear of the apparatus. This causes the engaged developer stay link 34 to slide toward the rear of the apparatus in the direction of arrow R, and the two developer pressure pieces (32, 33) integrally formed through the developer support member 301, which is a sliding member, also slide in the direction R. This means that, as shown in FIG. 15, the two developer pressure pieces (32, 33) are disengaged from the positions holding the developer unit 24, and the developer unit 24 moves due to its own weight in the direction of arrow D, which is a direction away from the photosensitive drum 2. As described above, the developer unit 24 moves away from the photosensitive drum 2 in conjunction with the opening of the inner door 102. Note that when closing the inner door 102, the developer unit 24 approaches the photosensitive drum 2 through the reverse procedure of the opening operation.

[0038] <Exposure unit contact / separation mechanism> Next, the contact / separation mechanism of the exposure unit 4 will be described with reference to Figures 16(a) and 16(b). Figure 16(a) shows the exposure unit 4 in the exposure position, and Figure 16(b) shows the exposure unit 4 in the separated position. As shown in Figures 16(a) and 16(b), the contact / separation mechanism 520 of the exposure unit 4 includes a frame body 521, a slide member 522, and a link mechanism 530. The frame body 521 is formed by bending a metal plate into a U-shape by press working. The frame body 521 is an elongated member extending in the direction of the rotation axis of the photosensitive drum 2, and both longitudinal ends are fixed to the apparatus main body 100A.

[0039] A slide member 522 is provided on one longitudinal end (front side) of the frame body 521 so as to be movable longitudinally relative to the frame body 521. When the slide member 522 moves longitudinally, link mechanisms 530 provided on both ends of the frame body 521 rotate, moving the exposure unit 4 up and down. The link mechanism 530 includes a link member 531 that connects the housing support member 55 of the exposure unit 4 to the slide member 522, and a link member 532 that connects the link member 531 to the frame body 521. As the inner door 102 opens and closes, the slide member 522 slides longitudinally relative to the frame body 521. The link members 531 and 532 rotate in conjunction with the sliding movement of the slide member 522, and the exposure unit 4 moves up and down. 16(a), when the slide member 522 is moved forward relative to the frame body 521, the link members 531 and 532 rotate in conjunction with the movement, and the exposure unit 4 rises to the exposure position. On the other hand, when the slide member 522 is moved rearward relative to the frame body 521, the link members 531 and 532 rotate in conjunction with the movement, and the exposure unit 4 falls to the separated position, as shown in FIG.

[0040] <Cleaning materials> Foreign matter such as toner or paper dust may adhere to the lens array 52 of the exposure unit 4. This undesirably blocks the light emitted from the light-emitting element 51, resulting in image defects such as uneven density in the image formed on the sheet S. Therefore, the lens array 52 can be cleaned by a cleaning member prepared by the user. In the contact / separation mechanism 520 described above, an insertion guide 550 into which the cleaning member can be inserted is provided at one longitudinal end (front side) of the frame body 521. The insertion guide 550, which serves as a guide, restricts the movement of the cleaning member, which is reciprocated longitudinally by the user, so that it does not separate from the lens array 52, thereby enabling the user to reliably clean the lens array 52. ​​FIG. 17 is a perspective view showing the cleaning member 600.

[0041] As shown in FIG. 17, the cleaning member 600 has a rubbing portion 601, a gripping portion 602, and a rod-shaped member 603. The rod-shaped member 603 is molded into a long, thin rod shape using a resin (plastic) such as PC / ABS or PP, and is not easily broken even when bent. The rod-shaped member 603 has a rubbing portion 601 at the tip of one longitudinal end (rear side) for cleaning the lens array 52, and a gripping portion 602 that can be gripped by a user at the other longitudinal end (front side). The user can clean the lens array 52 by gripping the gripping portion 602 and inserting the cleaning member 600 through the insertion guide 550 and moving it back and forth. To clean the exposure unit 4, the user first opens the front cover 101 and then opens the inner door 102 (see FIG. 8). When the user inserts the cleaning member 600 into the insertion guide 550, the cleaning member 600 is moved along the lens array 52 by the insertion guide 550 with the rubbing portion 601 in contact with the lens array 52. ​​As the user reciprocates the cleaning member 600, the rubbing portion 601 rubs against the lens array 52, thereby cleaning the lens array 52.

[0042] <Developing unit cooling configuration> The developing unit 24 contains a developer container containing a conveying screw 7 and toner agitated and conveyed by the conveying screw 7. The temperature of the developing unit 24 rises due to frictional heat generated by the bearing of the conveying screw 7 and the toner as it rotates at high speed. Once image formation is complete, the temperature of the developing unit 24 gradually drops. However, as image formation continues, the temperature of the developing unit 24 continues to rise as long as the heat capacity of the developing unit 24 allows. Because toner is easily melted by heat, if the temperature of the developing unit 24 rises above a predetermined temperature, the toner melts in the developing container and adheres to the developing sleeve 5, resulting in poor coating of the developing sleeve 5 and poor development. To prevent this, the developing unit 24 must be cooled to prevent the temperature from rising above a predetermined temperature. The cooling configuration for the developing unit 24 will be described using FIG. 18 and FIG. 8. In FIG. 18, the air flow for cooling the developing unit 24 is indicated by dotted arrows.

[0043] To generate an airflow for cooling the developing unit 24, for example, a cooling fan (not shown) is attached to the front cover 101. Air blown by the cooling fan passes from the opening 41a of the front door duct 41 to the inner door duct 1021 of the inner door 102. The air that has passed through the inner door duct 1021 is guided to the underside of the developing unit 24 by the developing duct portion 105 and flows into the cooling space 310 surrounded by the developing unit 24 and the cartridge tray 30.

[0044] It is preferable that the size (cross-sectional area) of the inner door duct 1021 be large in order to take in more air. On the other hand, it is preferable that the gap (cooling space 310) between the upper surface of the developing support member 301 and the bottom surface of the developing unit 24 be kept to the minimum necessary size in order to avoid an increase in the size of the image forming apparatus 100 in the vertical direction. If air is passed directly from the inner door duct 1021 to the cooling space 310, which is significantly different in size, the sudden change in size increases the air flow resistance, and this may reduce the cooling efficiency of the developing unit 24 by the external air.

[0045] <Developing duct section> Therefore, the developing unit 24 is provided with a developing duct portion 105 at one end (front side) in the longitudinal direction. The developing duct portion 105 is provided with a developing duct 1051 that communicates with the cooling space 310 so that the airflow generated by the cooling fan is guided to the cooling space 310 via the inner door duct 1021. The developing duct 1051 is formed so that the size on the cooling space 310 side gradually becomes smaller than the size on the inner door duct 1021 side, and by smoothly communicating the inner door duct 1021 and the cooling space 310 without a sudden change in size, a decrease in the cooling efficiency of the developing unit 24 is suppressed.

[0046] The air flowing into the cooling space 310 via the front door duct 41, the inner door duct 1021, and the developing duct 1051 flows longitudinally from front to rear to cool the developing unit 24. As described above, in the cooling configuration for the developing unit 24 according to this embodiment, the cooling space 310 formed between the developing unit 24 and the developing device support member 301 forms a flow path through which the airflow generated by the cooling fan passes. Note that in this embodiment, the size of the developing duct 1051 is set larger than the size of the cleaning member 600 so that a sufficient amount of air can flow into the cooling space 310 to cool the developing unit 24.

[0047] As described above, the user opens the front cover 101 and the inner door 102 to clean the lens array 52 of the exposure unit 4 (see FIG. 8). When the inner door 102 is open, the insertion guide 550 is exposed, allowing the user to insert the cleaning member 600 into the insertion guide 550. However, when the inner door 102 is open, not only the insertion guide 550 but also the developing duct 1051 is exposed, meaning that the user may mistakenly insert the cleaning member 600 into the developing duct 1051.

[0048] If the cleaning member 600 is incorrectly inserted into the development duct 1051, there is a risk of damage to the cleaning member 600 or the developing unit 24. Therefore, it is necessary to prevent the cleaning member 600 from being incorrectly inserted into the development duct 1051. To prevent the incorrect insertion into the development duct 1051, it is conceivable to reduce the size of the development duct 1051 so that the cleaning member 600 cannot be inserted. However, reducing the size of the development duct 1051 reduces the cooling efficiency of the developing unit 24. In consideration of the above, this embodiment ensures that the size of the development duct 1051 is larger than the size of the cleaning member 600, thereby preventing the user from inserting the cleaning member 600 into the development duct 1051 while suppressing a decrease in the cooling efficiency of the developing unit 24. The development duct rib for achieving this will be described below with reference to FIGS. 19 and 20 .

[0049] <Developing duct rib> 19, the development duct portion 105 has a development duct rib 900, and the development duct rib 900 is disposed in the development duct 1051. The development duct rib 900 as a regulating portion is provided to regulate the cleaning member 600 from entering the development duct 1051 from outside the apparatus main body 100A. When viewed in the rotation axis direction of the photosensitive drum 2 (front-rear direction in this case), the development duct rib 900 is provided in the development duct 1051 so as to overlap with the rubbing portion 601 (see FIG. 17) when the cleaning member 600 is positioned at the inlet of the development duct 1051 through which air flows in from outside the apparatus main body 100A.

[0050] The developing duct rib 900 is a rib that extends from the inlet of the developing duct 1051 in the direction of the rotation axis so as to divide an inlet region 1052 of the developing duct 1051 when viewed in the direction of the rotation axis. In the case of this embodiment, the developing duct rib 900 is provided across the developing duct portion 105 in the left-right direction so as to divide the inlet region 1052 of the developing duct portion 105 into two, upper and lower.

[0051] As shown in FIG. 20 , the thickness of the development duct rib 900 increases vertically from the inlet to the outlet of the air within the development duct 1051 (development duct). That is, the development duct rib 900 is formed so that the rib thickness gradually increases toward the rear, from the rib thickness "h" at the front of the apparatus main body 100A to the rib thickness "H" at the rear, such that "H>h." This is because, from the perspective of air flow resistance, it is undesirable to suddenly change the size (cross-sectional area) of the flow path within the development duct 1051. However, if the entire development duct rib 900 is thin, the strength of the development duct rib 900 will decrease. Therefore, to prevent an increase in air flow resistance, the thickness of the development duct rib 900 on the inlet side (front side) is made thin, while the thickness of the development duct rib 900 on the outlet side (rear side) is made thicker to maintain strength. The air divided by the developing duct ribs 900 flows vertically through the developing duct 1051 and into the cooling space 310 formed between the developing support member 301 and the developing unit 24 .

[0052] As described above, in this embodiment, the development duct rib 900 is disposed in the development duct 1051 provided in the development unit 24 to allow communication between the inner door duct 1021 and the cooling space 310 and external air. The size (cross-sectional area) of the development duct 1051 is larger than the size of the cleaning member 600 so that a sufficient amount of air can flow into the cooling space 310 to cool the development unit 24. Therefore, if a user mistakenly attempts to insert the cleaning member 600 into the development duct 1051, the rubbing portion 601 of the cleaning member 600 hits the development duct rib 900, preventing the cleaning member 600 from entering the development duct 1051. As a result, by providing the development duct rib 900 in the development duct 1051, it is possible to prevent the cleaning member 600 from being mistakenly inserted into the cooling space 310 without making the size of the development duct 1051 smaller than the size of the cleaning member 600, while suppressing a decrease in the cooling efficiency of the development unit 24.

[0053] Even if a user accidentally attempts to insert the cleaning member 600 into the inner door duct 1021 (see FIG. 8) of the inner door 102 in a closed state, the developing duct rib 900 is provided in the developing duct 1051, so the cleaning member 600 will not enter the developing duct 1051. Therefore, if the developing duct rib 900 is provided in the developing duct 1051, it is not necessary to provide something like the developing duct rib 900 in the inner door duct 1021 to prevent the cleaning member 600 from being inserted. This allows the size of the inner door duct 1021 to be as large as possible, thereby making it possible to reduce the air flow resistance described above.

[0054] <Other embodiments> In the above-described embodiment, the development duct rib 900 is provided so as to divide the inlet region 1052 of the development duct portion 105 into two, upper and lower, but this is not limited thereto. Several other examples of the development duct rib 900 are shown in FIG. 21. For example, as shown in FIG. 21, the development duct rib 900 may be provided so as to divide the inlet region 1052 of the development duct portion 105 into two, left and right, or may be provided at an angle to the inlet of the development duct portion 105. The development duct rib 900 only needs to be provided in the development duct 1051 so that the rubbing portion 601 of the cleaning member 600 that is incorrectly inserted hits it.

[0055] However, if the development duct rib 900 is provided so as to divide the inlet region 1052 of the development duct portion 105 into two halves, left and right, or so as to be inclined obliquely with respect to the inlet of the development duct portion 105, the external air is likely to be divided and the amount of air flowing in the left and right directions is likely to increase. If the amount of air flowing in the left and right directions increases, this may affect the air flow of the development units 24 of different colors that are arranged adjacently, and there is a risk that the cooling efficiency of the adjacent development units 24 may decrease. Therefore, as described above, it is preferable to provide the development duct rib 900 so as to divide the inlet region 1052 of the development duct portion 105 into two halves, top and bottom.

[0056] Alternatively, the developing duct rib 900 is not limited to a shape that divides the region 1052, and may be one or more protruding members 901 that protrude from the inner wall of the developing duct portion 105 without dividing the region 1052. However, the number and height of the protruding members 901 are set so that the size (cross-sectional area) of the developing duct 1051 does not become too small. [Explanation of symbols]

[0057] 2...photosensitive member (photosensitive drum), 4...exposure section (exposure unit), 24...development section (development unit), 51...light emitting element, 52...lens array, 100...image forming apparatus, 100A...apparatus main body, 102Y, 102M, 102C, 102K...door (inner door), 301...support section (development support member), 550...guide section (insertion guide), 600...cleaning member, 601...sliding section, 603...rod-shaped body, 900...regulating section (development duct rib), 1051...development duct, S...recording material (sheet)

Claims

1. A device body, A rotating photoreceptor; an exposure unit including a plurality of light-emitting elements arranged in a rotational axis direction of the photosensitive member and emitting light, and a lens array including a plurality of lenses for concentrating the light emitted from the light-emitting elements onto the surface of the photosensitive member, and exposing the surface of the photosensitive member to light to form an electrostatic latent image; a developing unit that develops the electrostatic latent image on the photosensitive member into a toner image; a support portion that supports the developing unit, the support portion forming a space between the developing unit and the support portion through which air can flow; a guide portion that is provided on one end side of the lens array in the direction of the rotation axis and that guides a cleaning member having a cleaning portion for cleaning the lens array from outside the device body to the lens array along the direction of the rotation axis; a development duct provided at the one end of the space in the direction of the rotation axis, for allowing air to flow into the space from the outside of the apparatus main body; a restricting portion that restricts the cleaning member from entering the developing duct from the outside of the apparatus main body, An image forming apparatus characterized by:

2. the cleaning member has a rod-shaped body that can be held by a user, and a rubbing portion attached to a tip of the rod-shaped body for rubbing the lens array, when the cleaning member is positioned with the rubbing portion overlapping an inlet of the developing duct through which air flows in from the outside of the apparatus body as viewed in the direction of the rotation axis, the regulating portion is provided on the developing duct so as to overlap the rubbing portion as viewed in the direction of the rotation axis; 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

3. The restriction portion divides a region of the inlet when viewed in the rotation axis direction.

3. The image forming apparatus according to claim 2, wherein the image forming apparatus is a recording medium.

4. the regulating portion is a rib extending from the inlet in the direction of the rotation axis within the developing duct.

4. The image forming apparatus according to claim 3, wherein the image forming apparatus is a recording medium.

5. The rib divides the inlet region in the vertical direction.

5. The image forming apparatus according to claim 4.

6. the thickness of the rib in the vertical direction increases from the inlet to the outlet of the air within the development duct; 6. The image forming apparatus according to claim 5,

7. a door provided in an openable and closable manner in front of the developing duct in the direction of the rotation axis, the door has a door duct communicating with the inlet so that air can flow into the developing duct from the outside of the apparatus main body when the door is in a closed state; 7. The image forming apparatus according to claim 3, wherein the image forming apparatus is a recording medium.

Images