Optical print head cleaning member and image forming apparatus equipped with the cleaning member

Abstract

To realize a function, which maintains a state where a rubbing member rubs a light emission surface of a lens array when a cleaning member inserted into an image formation device is moved relative to a metallic holding body, with a simple structure.SOLUTION: A cleaning part 601 has a restriction part comprising protruding parts 680a, 681a and side wall parts 680, 681. The cleaning part 601 is restricted from moving relative to a holding body 505 in a lens optical axis direction by the protruding parts 680a, 681a when moving in conjunction with reciprocating operation of a cleaning member conducted by an operator. Restricting the movement of the cleaning part 601 in the lens optical axis direction allows a cleaning blade 606 provided at a wall surface part 682 to be maintained in a state where the cleaning blade 606 contacts with a lens array 506. Further, the cleaning part 601 is restricted from moving relative to the holding body 505 in a lateral direction by the side wall parts 680, 681 to be less likely to be removed from the holding body 505 when moving.SELECTED DRAWING: Figure 10

Description

Technical Field

[0001] The present invention relates to a cleaning member for cleaning an optical print head suitable for use in an electrophotographic image forming apparatus such as a printer, a copier, a facsimile machine or a multifunction peripheral.

Background Art

[0002] Conventionally, as an exposure device for exposing a photosensitive drum, for example, an image forming apparatus employing an optical print head provided with a plurality of light emitting elements such as LEDs (Light Emitting Diodes) and organic ELs (Electro Luminescence) has been proposed. In this optical print head, a plurality of light emitting elements are arranged along the rotation axis direction of the photosensitive drum (main scanning direction of the exposure device). Then, in order to condense the light emitted from each light emitting element onto the surface of the photosensitive drum, the optical print head has a lens array in which a plurality of refractive index distribution type lenses are arranged in the main scanning direction so as to face each light emitting element. Since the focal length of this lens array is extremely short, the lens array is arranged so as to be located at a position close to the photosensitive drum when exposing the photosensitive drum.

[0003] As described above, since the lens array is located at a position close to the photosensitive drum, foreign substances such as toner and paper dust are likely to adhere to the light emitting surface of the lens array. When foreign substances adhere to the light emitting surface of the lens array, the amount of light irradiated from the light emitting elements tends to be uneven when exposing the photosensitive drum, and as a result, image defects such as density unevenness occur in the recorded material on which the image is formed. Therefore, in order to clean the lens array (specifically, the light emitting surface), a detachable cleaning means has been proposed for the optical print head (Patent Document 1). In this case, an operator such as a user or a service technician inserts a cleaning member into the image forming apparatus and manually reciprocates the inserted cleaning member in the main scanning direction. Then, since the cleaning blade provided at the tip of the cleaning member is moved while rubbing the lens array, foreign substances on the light emitting surface of the lens array can be removed by the rubbing member.

[0004] In the apparatus described in Patent Document 1, a protrusion is formed on the holder (housing) that holds the lens array and light-emitting element along the main scanning direction, and this protrusion forms a guide groove that guides the cleaning member in the main scanning direction. In this configuration, when the operator attaches the cleaning member to the optical print head, the operator engages the engaging portion formed on the cleaning member with the protrusion (guide groove) on the holder. This allows the operator to move the cleaning member back and forth against the optical print head while rubbing the cleaning blade against the light-emitting surface of the lens array. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2019-3113 [Overview of the project] [Problems that the invention aims to solve]

[0006] Incidentally, the holder described above is made of resin. However, if the holder is made of resin, there is a risk of deformation due to warping during molding or linear expansion due to temperature rise during operation of the main unit. As mentioned above, because the focal length of the lens array is extremely short, even slight deformation of the holder will cause the lens array's focus to not align with the surface of the photosensitive drum, making it difficult to properly expose the photosensitive drum. Therefore, it is conceivable to form the holder by bending sheet metal (such as electro-galvanized steel sheet), which is less prone to deformation than resin. However, in that case, compared to when the holder is made of resin, it is more difficult to process the convex portion and form the guide groove, resulting in challenges such as increased effort and cost. It is also conceivable to form the holder by welding multiple sheet metal pieces, including a sheet metal piece with a convex portion already formed, but such a configuration is also time-consuming and costly, making it unsuitable. For this reason, when the holder is made of metal, it was difficult for the engaging portion of the conventional cleaning member to engage with the holder.

[0007] The present invention has been made in view of the above problems, and aims to provide a cleaning member for an optical print head that can be moved by an operator relative to a metal holder while maintaining a state in which the cleaning blade and the lens array are rubbing against each other. [Means for solving the problem]

[0008] The cleaning member according to the present invention is a cleaning member that is removable from an image forming apparatus comprising: a substrate having a plurality of light-emitting elements that emit light; a lens array having a plurality of lenses that focus the light emitted from the light-emitting elements onto the surface of a photosensitive drum; and a metal holder having a support portion that supports the lens array with the light-emitting surface of the lens array exposed on the arrangement side where the photosensitive drum is placed, and two opposing wall portions that face each other in a width direction intersecting the optical axis direction of the lenses and extend from the support portion toward the side opposite to the arrangement side. The device comprises a rod-shaped body and a cleaning section provided on the rod-shaped body and inserted together with the rod-shaped body into the image forming apparatus, wherein, when the cleaning section is inserted into the image forming apparatus and moves together with the rod-shaped body, the cleaning section has restricting sections at the tips of each of the opposing wall portions that abut against the holder in the optical axis direction from the side opposite to the arrangement side, while the sliding member is rubbing against the light-emitting surface, thereby restricting the movement of the cleaning section in the optical axis direction away from the light-emitting surface.

[0009] The cleaning member according to the present invention is a cleaning member that is removable from an image forming apparatus comprising: a substrate having a plurality of light-emitting elements that emit light; a lens array having a plurality of lenses that focus the light emitted from the light-emitting elements onto the surface of a photosensitive drum; a metal holder having a support portion that supports the lens array with the light-emitting surface of the lens array exposed on the side where the photosensitive drum is placed, and a first opposing wall portion and a second opposing wall portion that face each other in a width direction intersecting the optical axis direction of the lenses and extend from the support portion toward the side opposite to the placement side; and The present invention relates to a rod-shaped body and a cleaning unit provided on the rod-shaped body and inserted together with the rod-shaped body into the image forming apparatus, wherein the cleaning unit, when inserted into the image forming apparatus and moving together with the rod-shaped body, has a restricting portion at the tip of the first opposing wall portion that abuts against the holder in the optical axis direction from the side opposite to the arrangement side, while the sliding member is rubbing against the light-emitting surface, thereby restricting the movement of the cleaning unit in the optical axis direction away from the light-emitting surface. [Effects of the Invention]

[0010] According to the present invention, when a cleaning member inserted into an image forming apparatus moves against a metal holder, the abrasive member can be easily maintained in a state of abrasive contact with the light-emitting surface of the lens array, thereby enabling the operator to properly clean the optical print head with the cleaning member. [Brief explanation of the drawing]

[0011] [Figure 1] A schematic cross-sectional view of an image forming apparatus. [Figure 2] This diagram illustrates the structure of the drum unit and the surrounding area of ​​the developing unit, with (a) showing the unit in the installed state and (b) showing the unit in the process of being removed. [Figure 3] This is a perspective view showing a part of the exposure unit, where (a) is the exposure device in the exposure position and (b) is the exposure device in the retracted position. [Figure 4] A schematic diagram illustrating an exposure apparatus. [Figure 5] (a) Perspective view showing the substrate, (b) View of the substrate from the photosensitive drum side, (c) View showing the light-emitting elements on the substrate, (d) View of the lens array from the photosensitive drum side, (e) Perspective view showing the lens array. [Figure 6] An enlarged view showing part of the lifting mechanism. [Figure 7] A perspective view showing the cleaning member of this embodiment. [Figure 8] A diagram illustrating the cleaning operation of a lens array using a cleaning component. [Figure 9] (a) Perspective view showing the vicinity of the cleaning area, (b) Cross-sectional view showing the vicinity of the cleaning area. [Figure 10] A cross-sectional diagram illustrating the positional relationship between the cleaning unit and the holder during cleaning. [Figure 11] A cross-sectional view illustrating the sealing component. [Figure 12] This diagram illustrates the procedure for attaching the cleaning unit to the rod-shaped body, showing (a) the first step, (b) the second step, (c) the third step, and (d) the fourth step. [Figure 13] A cross-sectional view illustrating another embodiment. [Modes for carrying out the invention]

[0012] The following describes embodiments for carrying out the present invention. Unless otherwise specifically stated, the dimensions, materials, shapes, and relative arrangements of the components described below are not intended to limit the scope of this invention to those specific components.

[0013] <Image forming apparatus> First, the general configuration of the image forming apparatus 1 will be explained using Figures 1 to 2(b). The image forming apparatus 1 shown in Figure 1 is a device that employs a so-called "bottom exposure method," in which the photosensitive drums 103Y, 103M, 103C, and 103K are exposed from below by the exposure units 520Y, 520M, 520C, and 520K. Note that the image forming apparatus 1 may also be a device that employs a "top exposure method," in which the photosensitive drums 103Y, 103M, 103C, and 103K are exposed from above.

[0014] As shown in Figure 1, the image forming apparatus 1 includes four image forming units 102Y, 102M, 102C, and 102K (hereinafter collectively referred to as "image forming unit 102") that form toner images of yellow, magenta, cyan, and black, respectively. Each of the image forming units 102Y, 102M, 102C, and 102K is equipped with a photosensitive drum 103Y, 103M, 103C, and 103K (hereinafter collectively referred to as "photosensitive drum 103"). The image forming units 102Y, 102M, 102C, and 102K are also equipped with chargers 104Y, 104M, 104C, and 104K (hereinafter collectively referred to as "charger 104") that charge the photosensitive drums 103Y, 103M, 103C, and 103K, respectively. The image forming units 102Y, 102M, 102C, and 102K are equipped with exposure units 520Y, 520M, 520C, and 520K (hereinafter collectively referred to as "exposure unit 520") that expose the photosensitive drums 103Y, 103M, 103C, and 103K to form an electrostatic latent image. These exposure units 520 have LEDs (Light Emitting Diodes) as exposure light sources capable of emitting light, as will be described in detail later. Furthermore, the image forming units 102Y, 102M, 102C, and 102K are equipped with developer units 106Y, 106M, 106C, and 106K (hereinafter collectively referred to as "developer unit 106"). These developer units 106 develop the electrostatic latent image on the photosensitive drum 103 into a toner image using toner.

[0015] The image forming apparatus 1 includes an intermediate transfer belt 107 to which the toner image formed on the photosensitive drum 103 is transferred, and primary transfer rollers 108Y, 108M, 108C, and 108K that sequentially transfer the toner image formed on the photosensitive drum 103 to the intermediate transfer belt 107. The image forming apparatus 1 also includes a secondary transfer roller 109 for transferring the toner image on the intermediate transfer belt 107 to the recording material P transported from the paper feeding unit 101, and a fuser 110 for fixing the secondary transferred image to the recording material P. The recording material P can be any type of sheet material such as plain paper, cardboard, rough paper, textured paper, coated paper, glossy paper, photographic paper, plastic film, or cloth.

[0016] <Image forming process> The exposure unit 520Y exposes the surface of the photosensitive drum 103Y charged by the charger 104Y. As a result, an electrostatic latent image is formed on the photosensitive drum 103Y. Next, the developing unit 106Y develops the electrostatic latent image formed on the photosensitive drum 103Y with yellow toner. The yellow toner image developed on the surface of the photosensitive drum 103Y is transferred onto the intermediate transfer belt 107 by the primary transfer roller 108Y. The magenta, cyan, and black toner images are also transferred onto the intermediate transfer belt 107 by the same image forming process.

[0017] The toner images of each color transferred onto the intermediate transfer belt 107 are conveyed by the intermediate transfer belt 107 to the secondary transfer section T2. A transfer bias for transferring the toner image onto the recording material P is applied to the secondary transfer roller 109 disposed in the secondary transfer section T2. The toner image conveyed to the secondary transfer section T2 is transferred onto the recording material P conveyed from the paper feed section 101 by the transfer bias of the secondary transfer roller 109. The recording material P onto which the toner image has been transferred is conveyed to the fixing unit 110. The fixing unit 110 fixes the toner image onto the recording material P by heat and pressure. The recording material P onto which the toner image has been fixed by the fixing unit 110 is discharged outside the machine from the paper discharge section 111.

[0018] <Drum unit and developing unit> As shown in FIGS. 2(a) and 2(b), drum units 518Y, 518M, 518C, and 518K (hereinafter also collectively referred to as "drum unit 518") are attached to the image forming apparatus 1. The drum unit 518 is a cartridge that is replaced by an operator such as a user or a service technician. The drum unit 518 rotatably supports the photosensitive drum 103.

[0019] In addition, the image forming apparatus 1 is provided with developing units 641Y, 641M, 641C, and 641K (hereinafter, also collectively referred to as "developing unit 641") that are separate from the drum unit 518. The developing unit 641 is a cartridge in which the developer 106 shown in FIG. 1 and the toner storage section are integrated. The developer 106 includes a developing sleeve (not shown) that carries the developer. The developing unit 641 is provided with a plurality of gears for rotating a screw for stirring the toner and the carrier. When these gears are deteriorated over time or the like, an operator removes the developing unit 641 from the apparatus main body 1A of the image forming apparatus 1 and replaces it. Note that the drum unit 518 and the developing unit 641 are not limited to being configured as separate cartridges, and may be configured as a process cartridge in which the drum unit 518 and the developing unit 641 are integrated.

[0020] The image forming apparatus 1 includes a front side plate 642 and a rear side plate 643 formed of sheet metal. The front side plate 642 is a side wall provided on the front side of the image forming apparatus 1 and forms a part of the housing of the apparatus main body 1A on the front side of the image forming apparatus 1. The rear side plate 643 is a side wall provided on the back side of the image forming apparatus 1 and forms a part of the housing of the apparatus main body 1A on the back side of the image forming apparatus 1. The front side plate 642 and the rear side plate 643 are arranged facing each other, and a sheet metal (not shown) is bridged between them as a beam. In this specification, the front side refers to the side on which an operator inserts and removes the drum unit 518 with respect to the apparatus main body 1A.

[0021] An opening is formed in the front plate 642 of the image forming apparatus 1, allowing the operator to easily insert and remove the drum unit 518 and the developing unit 641 from the front side. The drum unit 518 and the developing unit 641 are mounted in predetermined positions on the main body of the image forming apparatus 1 through the opening (mounting position). The image forming apparatus 1 also includes covers 558Y, 558M, 558C, and 558K (hereinafter collectively referred to as "cover 558") that cover the front sides of both the drum unit 518 and the developing unit 641 mounted in the mounting position. One end of each cover 558 is fixed to the main body of the image forming apparatus 1 by a hinge, and the cover 558 is rotatable relative to the main body of the image forming apparatus 1 by the hinge. The replacement work is completed when the operator opens the cover 558, removes the drum unit 518 or developing unit 641 from inside the main body, inserts a new drum unit 518 or developing unit 641, and closes the cover 558.

[0022] Here, as shown in Figure 2(b), in the following explanation, the side with the front plate 642 will be referred to as the front side (front or front) and the side with the rear plate 643 as the rear side (back or back) with respect to the main body 1A of the device. Furthermore, the side where the photosensitive drum 103K, on ​​which an electrostatic latent image of the black toner image is formed, is located is defined as the right side, and the side where the photosensitive drum 103Y, on which an electrostatic latent image of the yellow toner image is formed, is located is defined as the left side. In addition, the upward direction in the vertical direction perpendicular to the front-to-back and left-to-right directions defined here will be referred to as the upward direction, and the downward direction in the vertical direction will be referred to as the downward direction. The rotation axis direction of the photosensitive drum 103 coincides with the front-to-back direction shown in Figure 2(b), and the longitudinal direction of the exposure device 105, which will be described later, also coincides with the front-to-back direction shown in Figure 2(b). In other words, the rotation axis direction of the photosensitive drum 103 and the longitudinal direction of the exposure device 105 (see Figure 3(a)) are in the same direction.

[0023] <Exposure Unit> Next, the exposure unit 520 will be described using Figures 3(a) to 6 with reference to Figure 1. As shown in Figure 1, in this embodiment, the exposure unit 520 is positioned vertically below the rotation axis of the photosensitive drum 103 in order to expose the photosensitive drum 103 from below. The exposure unit 520 includes an exposure device 105, a support member 526, a link mechanism 530, a positioning pin 514, and an insertion guide 550, as shown in Figures 3(a) and 3(b). Although not shown here, the link mechanism 530 and the positioning pin 514 are provided not only on the front side but also on the rear side of the exposure unit 520.

[0024] First, the exposure device 105 (optical print head) will be described. The exposure device 105 has a longitudinal shape extending in the direction of the rotation axis of the photosensitive drum 103, and is an LED exposure type that exposes the photosensitive drum 103 using a plurality of light-emitting elements such as LEDs arranged along the rotation axis of the photosensitive drum 103. As shown in Figure 4, the exposure device 105 comprises a substrate 502, a holder 505, and a lens array 506. The substrate 502 and the lens array 506 are held by the holder 505 so as to face each other in the vertical direction. In this embodiment, the lens array 506 is supported by a support part 582 such that the light-emitting surface of the lens array 506 is exposed on the side where the photosensitive drum 103 is placed. The substrate 502 is held by two opposing wall portions (580, 581) that are positioned opposite each other in the width direction intersecting the optical axis direction of the lens 507 (see Figure 5(d) described later) and extend from the support portion 582 toward the side opposite to where the photosensitive drum 103 is located.

[0025] The holder 505 is a metal component formed by bending a sheet metal that has been plated, such as a galvanized steel sheet or a cold-rolled steel sheet. In order to properly expose the photosensitive drum 103 by the exposure device 105, the holder 505 needs to have sufficient strength to resist deformation by external forces and heat, so that when the exposure device 105 is in the exposure position described later, the focal point of the lens array 506 always aligns with the surface of the photosensitive drum 103. Therefore, in this embodiment, a holder 505 formed by bending a sheet metal into a roughly U-shape is used. By forming the holder 505 by bending a sheet metal, sufficient strength to resist deformation by external forces and heat is ensured, and manufacturing costs can be reduced.

[0026] As shown in Figure 5(a), LED chips 639 are mounted on one side of the substrate 502, and a connector 504 is provided on the other side of the substrate 502. Although not shown, the substrate 502 is also provided with wiring for supplying control signals to each LED chip 639. One end of a flexible flat cable (FFC), not shown, is connected to the connector 504. The other end of this FFC is connected to a control unit, not shown, provided on the main body of the image forming apparatus 1. In this case, when a control signal is input from the control unit of the image forming apparatus 1 via the FFC and connector 504, the LED chips 639 are driven according to the control signal supplied via the wiring.

[0027] As shown in Figure 5(b), multiple LED chips 639-1 to 639-29 (29 in this case) are arranged on one side of the substrate 502. Each LED chip 639-1 to 639-29 has 516 LEDs arranged in a row along the longitudinal direction of the substrate 502 (the direction of the rotation axis of the photosensitive drum 103). As shown in Figure 5(c), the distance k2 between the centers of adjacent LEDs 503 on LED chip 639 corresponds to the resolution of the image forming apparatus 1. For example, if the resolution of the image forming apparatus 1 is "1200 dpi", the LEDs 503 are arranged in a row such that the distance k2 between the centers of adjacent LEDs 503 is "21.16 μm". In this case, the exposure range of the exposure apparatus 105 is "approximately 316 mm". Here, the photosensitive layer of the photosensitive drum 103 is formed to have a width of, for example, "316 mm" or more with respect to the rotation axis direction. Since the length of the long side of an A4-sized recording material and the length of the short side of an A3-sized recording material are both 297 mm, in this embodiment, the exposure device 105 has an exposure range capable of forming images on both the A4-sized and A3-sized recording materials.

[0028] The LED chips 639-1 to 639-29 described above are arranged alternately in two rows along the rotation axis of the photosensitive drum 103. That is, as shown in Figure 5(b), the odd-numbered LED chips 639-1, 639-3, ... 639-29, counting from the left side of the figure, are mounted in a single row along the longitudinal direction of the substrate 502. Then, the even-numbered LED chips 639-2, 639-4, ... 639-28 are mounted in a single row along the longitudinal direction of the substrate 502. In this way, as shown in Figure 5(c), the distance k1 between the centers of an LED 503 located at one end of one LED chip 639 and the LED 503 located at the other end of the adjacent LED chip 639 can be made equal to the distance k2 between the centers.

[0029] In this embodiment, an LED 503 is used as the light-emitting element, but an organic electroluminescent (OLED) may also be used as the light-emitting element.

[0030] Furthermore, as shown in Figure 5(d), a lens array 506 is provided on one side of the substrate 502 on which the LED chip 639 is mounted. The lens array 506 has multiple lenses 507, which are arranged in two rows along the arrangement direction of the multiple LEDs 503, and have the function of focusing the light emitted from the LEDs 503. As shown in Figure 5(e), each lens 507 of the lens array 506 is arranged such that it is in contact with both adjacent lenses 507 in the arrangement direction of the lenses 507 in the other row. The lens 507 is, for example, a cylindrical glass rod lens, and has an incident surface into which light emitted from the LEDs 503 enters, and an exit surface into which light that enters from the incident surface exits. Note that the material of the lens 507 is not limited to glass, but may be plastic. Also, the shape of the lens 507 is not limited to a cylinder, but may be a polygonal prism such as a hexagonal prism.

[0031] The dotted line Z shown in Figure 5(e) indicates the optical axis of lens 507. In this embodiment, as will be described later, the exposure device 105 is moved in a direction roughly aligned with the optical axis of lens 507, indicated by the dotted line Z, in order to bring the exposure device 105 closer to the photosensitive drum 103 in accordance with the focal length of the lens array 506 (for example, 3.0 ± 0.3 mm). The optical axis of lens 507 referred to here is the line connecting the center of the light-emitting surface of lens 507 and the focal point of lens 507.

[0032] In this embodiment, as shown in Figure 4, the lens array 506 forms a 1:1 upright image of the light beam emitted from the LED 503 onto the photosensitive drum 103. At this time, the distance from the LED 503 to the incident surface 506b of the lens array 506 and the distance from the light-emitting surface 506a of the lens array 506 to the surface of the photosensitive drum 103 are approximately equal. The distance from the LED 503 to the incident surface 506b of the lens array 506 requires high precision on the order of microns, in accordance with the focal length of the lens array 506. Therefore, after precisely adjusting this distance, the substrate 502 and the lens array 506 are fixed to the holder 505 by adhesive.

[0033] Next, the mechanism for reciprocating the exposure device 105 between an exposure position close to the photosensitive drum 103 and a retracted position away from the photosensitive drum 103 will be explained using Figures 3(a) to 3(b) and 6, with reference to Figure 2(a). The exposure position is a position close to the photosensitive drum 103 where the exposure device 105 can expose the surface of the photosensitive drum 103, and the retracted position is a position where the exposure device 105 is separated from the photosensitive drum 103 for maintenance such as cleaning. In this embodiment, the exposure device 105 moves between the exposure position and the retracted position in accordance with the opening and closing of the cover 558.

[0034] As shown in Figure 3(a), the holder 505 of the exposure apparatus 105 is provided with a positioning pin 514. In this embodiment, the positioning pin 514 is a straight metal pin. When the exposure apparatus 105 moves from the retracted position to the exposure position, this positioning pin 514 abuts against the drum unit 518. As a result, the exposure apparatus 105 stops with a gap formed between the light-emitting surface 506a (see Figure 4) of the lens array 506 and the surface of the photosensitive drum 103, corresponding to the focal length of the lens array 506. In this way, the exposure position of the exposure apparatus 105 relative to the photosensitive drum 103 is determined. In this embodiment, when the exposure apparatus 105 is in the exposure position, the distance between the surface of the photosensitive drum 103 and the light-emitting surface 506a of the lens array 506 is adjusted to approximately 3 mm, which is the focal length of the lens array 506. The length of the positioning pin 514 is determined to achieve this, and it is fixed to the holder 505 by welding or adhesive.

[0035] The support member 526 supports the exposure apparatus 105 via a link mechanism 530. The link mechanism 530 has a large link member 535 and a small link member 536, with the large link member 535 supporting the holder 505. The support member 526 is formed, for example, by bending a sheet of metal with a longitudinal shape extending in the direction of the rotation axis of the photosensitive drum 103 so that when it is cut perpendicular to its longitudinal direction, it has a roughly U-shaped cross section. This allows the link mechanism 530 and the slide member 525 described later to be arranged on the support member 526. The support member 526 is fixed to the main body 1A of the image forming apparatus 1 by fixing one end (front side) in the longitudinal direction to the front plate 642 and the other end (rear side) in the longitudinal direction to the rear plate 643.

[0036] The support member 526 is provided with a slide member 525 that is movable in the longitudinal direction of the support member 526. The slide member 525 slides in the front-rear direction relative to the support member 526 in conjunction with the opening and closing operation of the cover 558 provided on the front side of the image forming apparatus 1. As the slide member 525 slides relative to the support member 526, the large link member 535 and the small link member 536 rotate, causing the exposure apparatus 105 to reciprocate so as to move toward and away from the support member 526. This will be explained in detail below.

[0037] First, we will explain the case when the exposure device 105 moves from the state shown in Figure 3(a) to the state shown in Figure 3(b), that is, from the exposure position to the retracted position. As the cover 558 is opened, the slide member 525 slides from the front to the rear. When the slide member 525 slides from the front to the rear, the large link member 535 rotates counterclockwise. Since one end of the small link member 536 is rotatably connected to the support member 526, it rotates clockwise relative to the support member 526 in conjunction with the rotation of the large link member 535. Here, since the other end of the large link member 535 is rotatably connected to the holder 505, the large link member 535 rotates counterclockwise in conjunction with the slide member 525, causing the holder 505 to move away from the photosensitive drum 103. In this way, the exposure device 105 moves from the exposure position to the retracted position. In this embodiment, when the exposure apparatus 105 is in the retracted position, a gap is secured in the longitudinal direction that allows a part of the cleaning unit 601 to enter and pass between the end of the holder 505 and the support member 526 (see Figure 10, which will be described later).

[0038] Next, we will describe the case when the exposure device 105 moves from the state shown in Figure 3(b) to the state shown in Figure 3(a), that is, from the retracted position to the exposure position. As the cover 558 is closed, the slide member 525 slides from the rear to the front. When the slide member slides from the rear to the front, the large link member 535 rotates clockwise. At the same time, the small link member 536 rotates counterclockwise. In this way, the large link member 535 rotates clockwise in conjunction with the slide member 525, causing the holder 505 to move in a direction closer to the photosensitive drum 103. In this way, the exposure device 105 moves from the retracted position to the exposure position. In this embodiment, the direction of movement of the exposure device 105 between the retracted position and the exposure position is approximately the same as the optical axis direction of the lens array 506.

[0039] As shown in Figure 6, a cantilever shaft 540 is provided at the end of the large link member 535. Meanwhile, a torsion coil spring 547 is stretched over the holder 505, and the cantilever shaft 540 is in contact with a portion of the spring in a nearly perpendicular direction. When the large link member 535 rotates clockwise, the cantilever shaft 540 pushes the torsion coil spring 547, indirectly pushing up the holder 505. As described above, a positioning pin 514 is provided on the holder 505. The holder 505 is pushed up by the link mechanism 530, and when the tip of this positioning pin 514 abuts against a predetermined position on the drum unit 518, the holder 505 stops. In other words, the stroke of the link mechanism 530 is set to be greater than the required amount, and the torsion coil spring 547 absorbs the overstroke while biasing it, so that the holder 505 can be stopped at the appropriate position relative to the drum unit 518. Once the position of the holder 505 relative to the drum unit 518 is determined, the distance between the photosensitive drum 103 and the light-emitting surface 506a (see Figure 4) of the lens array 506 is also determined, and the movement of the exposure apparatus 105 to the exposure position is completed.

[0040] Furthermore, an insertion guide 550 is provided on one longitudinal end (front side) of the support member 526 into which a cleaning member 600 (see Figure 7), described later, is inserted. Since the support member 526 is fixed to the main body 1A of the image forming apparatus 1, the insertion guide 550 is also fixed to the main body 1A of the image forming apparatus 1. The insertion guide 550 restricts the movement of the cleaning member 600 in order to correctly guide the cleaning member 600 toward the holder 505 when the cleaning member 600, which is provided to be insertable and removable from the main body of the apparatus, is inserted.

[0041] <Cleaning materials> As already mentioned, if the light-emitting surface 506a of the lens array 506 becomes contaminated with foreign matter such as toner or paper dust that has fallen from the photosensitive drum 103, the light emitted from the contaminated part of the multiple lenses 507 will be partially blocked. This is undesirable because it can cause image defects such as density unevenness in the image formed on the recording material P. Therefore, a cleaning member capable of cleaning the lens array 506 (more specifically the light-emitting surface 506a) is provided in advance.

[0042] Figure 7 is a perspective view showing the cleaning member 600 of this embodiment. As shown in Figure 7, the cleaning member 600 of this embodiment has a cleaning section 601, a gripping section 602, and a rod-shaped body 603. The rod-shaped body 603, which is formed in an elongated rod shape, has a cleaning section 601 for cleaning the lens array 506 on one end in the longitudinal direction and a gripping section 602 on the other end. The operator can clean the light-emitting surface 506a of the lens array 506 by gripping the gripping section 602 and inserting and removing the cleaning member 600 from the image forming apparatus 1.

[0043] The cleaning member 600 is installed, for example, inside a front cover that is openable and closable on the front side of the image forming apparatus 1. The front cover is a door located on the front side of the image forming apparatus 1 that is opened and closed by an operator to replace the drum unit 518 or the developing unit 641, or to clean the lens array 506 using the cleaning member 600. When it becomes necessary to clean the lens array 506, the operator removes the cleaning member 600 from inside the front cover of the image forming apparatus 1. Note that the cleaning member 600 is not limited to being installed on the front cover; it may be installed on other parts of the image forming apparatus 1, or it may not be installed on the image forming apparatus 1 at all. Alternatively, a service technician (operator) may bring the cleaning member 600 each time cleaning is required.

[0044] Here, an overview of the actual cleaning operation of the lens array 506 using the cleaning member 600 will be explained with reference to Figure 8. In order to clean the exposure device 105, the operator first opens the front cover, and then opens the cover 558 (see Figure 2(a)). In this embodiment, the cover 558 opens and closes in conjunction with the opening and closing of the front cover. As the cover 558 is opened, the exposure device 105 moves from the exposure position to the retracted position.

[0045] The operator then removes the cleaning member 600 from the opened front cover and inserts the removed cleaning member 600 into the insertion guide 550. The cleaning section 601, located at the insertion end of the inserted cleaning member 600, is then guided by the insertion guide 550 and inserted into the exposure device 105, which has been moved to a retracted position. As will be described in more detail later, the cleaning section 601 moves while cleaning the exposure device 105 as the operator moves the cleaning member 600 back and forth.

[0046] Incidentally, when a metal holder 505 made by bending sheet metal is used in the exposure apparatus 105, as previously described, it was not easy to form a guide groove for guiding the cleaning member 600 in the holder 505 compared to a resin holder. However, in order for the lens array 506 to be reliably cleaned by the cleaning member 600, it is necessary to guide the cleaning member 600 which is reciprocated by the operator. Therefore, in this embodiment, the cleaning member 600 can be guided even when a holder 505 that has not been processed to guide the cleaning member 600, such as forming the protrusions described above, is used, that is, when a holder 505 without a guide groove is formed. To do this, the cleaning part 601 of this embodiment is formed so that, with respect to the optical axis direction of the lens 507, it can contact from the outside the end of the holder 505 on the side opposite to the side where the photosensitive drum 103 is placed, when the cleaning member 600 is inserted into the exposure apparatus 105. Note that since the "bottom exposure method" is given as an example here, the cleaning part 601 contacts the lower end of the holder 505 from the outside. The configuration for achieving this will be explained below using Figures 9(a) to 10.

[0047] The cleaning unit 601 of this embodiment has a wall portion 682. The wall portion 682 is provided in a position facing the lens array 506 when the cleaning member 600 is inserted into the exposure apparatus 105. As shown in Figures 9(a) and 9(b), a cleaning blade 606 is detachably attached to the wall portion 682. The cleaning blade 606 is a flexible member made of urethane rubber, for example, with a thickness of 0.5 mm, and is fixed so as to protrude, for example, about 3 mm from the wall portion 682 toward the lens array 506 side (inward).

[0048] The cleaning blade 606, acting as a sliding member, slides against the lens array 506 in response to the reciprocating motion of the cleaning member 600, thereby cleaning the lens array 506. In this embodiment, with respect to the width direction that intersects the optical axis direction of the lens 507 (see dotted line Z in Figure 5(e)) and the longitudinal direction of the rod-shaped body 603, the cleaning blade 606 extends in the width direction with respect to approximately the center of the wall portion 682. This makes it possible to reduce the moment generated by the reaction force between the cleaning blade 606 and the lens array 506 and the reaction force between the protrusions 680a, 681a and the holder 505, which will be described later, when the cleaning member 600 is moving back and forth. As a result, the posture of the cleaning unit 601 is stable when the cleaning member 600 is moving back and forth, so that the operator can smoothly clean the lens array 506.

[0049] The thickness and material of the cleaning blade 606 described above are merely examples; the cleaning blade 606 may be made of, for example, silicone rubber or resin. Alternatively, instead of using the cleaning blade 606, a cleaning pad made of sponge, or a cleaning pad with non-woven fabric attached to the surface of a sponge, may be used.

[0050] Furthermore, the cleaning section 601 of this embodiment has two side wall sections 680 and 681, which are provided opposite to the opposing wall section 580 (first opposing wall section) and the opposing wall section 581 (second opposing wall section), respectively. Here, an example is shown in which the first side wall section 680 and the second side wall section 681 are provided on both ends of the wall surface section 682 in the width direction, facing each other.

[0051] As shown in Figure 10, these side wall portions 680 and 681 extend from the wall portion 682 toward the holder 505 at both ends of the wall portion 682. When the cleaning member 600 is inserted into the exposure apparatus 105, these side wall portions 680 and 681 are located outside the opposing wall portions 580 and 581 of the holder 505. That is, the side wall portion 680 on the right side in the insertion direction of the cleaning unit 601 is located to the right (outside) in the figure than the opposing wall portion 580 of the holder 505, and the side wall portion 681 on the left side in the insertion direction is located to the left (outside) in the figure than the opposing wall portion 581 of the holder 505. In other words, the cleaning unit 601 is arranged so that its side wall portions 680 and 681 sandwich the holder 505 from the left and right directions. However, a small gap is maintained between the side wall portion 680 and the opposing wall portion 580, and between the side wall portion 681 and the opposing wall portion 580. Therefore, the cleaning portion 601 is allowed to move laterally relative to the holder 505 by the amount of this gap.

[0052] Furthermore, in this embodiment, the cleaning section 601 is formed such that, with respect to the optical axis direction of the lens 507, the cleaning member 600 can contact the lower end of the holder 505 on the side opposite to where the photosensitive drum 103 is located, from the outside, when the cleaning member 600 is inserted into the exposure apparatus 105. Specifically, as shown in Figure 9(a), the side walls 680 and 681 of the cleaning section 601 have inwardly projecting protrusions 680a and 681a. With respect to the width direction, these protrusions 680a and 681a are formed to a length that protrudes inward from the side walls 680 and 681, respectively, beyond the opposing wall portions 580 and 581 of the opposing holder 505. Also, with respect to the optical axis direction of the lens 507, the protrusions 680a and 681a are formed on the side walls 680 and 681 such that, when in contact with the lower ends of the opposing wall portions 580 and 581, the cleaning blade 606 on the wall surface 682 contacts the lens array 506.

[0053] In this embodiment, the protrusions 680a and 681a and the side wall portions 680 and 681 constitute a restricting portion. That is, as the cleaning portion 601 moves in conjunction with the reciprocating motion of the cleaning member 600, the protrusions 680a and 681a abut against the respective ends of the opposing wall portions 580 and 581 from the side opposite to the side where the photosensitive drum 103 is located, in the optical axis direction of the lens 507. As a result, the movement of the cleaning portion 601 in the optical axis direction of the lens 507 relative to the holder 505 is restricted. In this embodiment, since the image forming apparatus 1 employs a bottom exposure method, the protrusions 680a and 681a abut against the respective ends of the opposing wall portions 580 and 581 from below in the vertical direction. By restricting the movement of the cleaning portion 601 in the optical axis direction of the lens 507 in this way, the cleaning blade 606 provided on the wall portion 682 is maintained in a state where it is rubbing against the light emitting surface of the lens array 506 from above in the vertical direction.

[0054] Furthermore, the side walls 680, 681 restrict the movement of the cleaning unit 601 in the left-right direction (sub-scanning direction) relative to the holder 505 when it moves in conjunction with the reciprocating motion of the cleaning member 600. By restricting the left-right movement of the cleaning unit 601, it becomes difficult for the cleaning unit 601 to detach from the holder 505 during movement. In other words, the holder 505 functions as a guide rail that guides the longitudinal movement of the cleaning unit 601, which is positioned to cover the holder 505 with the cleaning blade 606 in contact with the lens array 506. As a result, the cleaning unit 601 can move longitudinally relative to the holder 505 while maintaining contact between the cleaning blade 606 and the lens array 506.

[0055] As described above, the protrusions 680a and 681a abut against the respective ends of the opposing wall portions 580 and 581 from below in the vertical direction, thereby "restricting" the movement of the cleaning portion 601 relative to the holder 505, although some movement is permitted. Specifically, as long as the cleaning portion 601 is in contact with the light-emitting surface of the lens array 506, it is acceptable for the cleaning portion 601 to move toward the photosensitive drum 103. For example, the movement of the cleaning portion 601 relative to the holder 505 should be restricted within the tolerance range between the parts or within the range of slight looseness when the cleaning member 600 is engaged with the holder 505.

[0056] As described above, in this embodiment, with the cleaning member 600 inserted into the metal holder 505 that holds the lens array 506, a portion of the cleaning section 601 is made to contact the end opposite to the side where the photosensitive drum 103 is located from the outside. To achieve this, the cleaning section 601 has protrusions 680a and 681a formed on the side walls 680 and 681 that abut against the lower ends of the opposing walls 580 and 581 of the holder 505 when the cleaning blade 606 is in contact with the lens array 506. With this simple configuration, a portion of the cleaning section 601 can be made to contact the end of the holder 505 from the outside, thereby restricting the movement of the cleaning section 601 in the optical axis direction relative to the holder 505. As a result, the cleaning section 601 reciprocates relative to the holder 505 while maintaining contact between the cleaning blade 606 and the lens array 506, making it easy for the operator to properly clean the lens array 506 with the cleaning member 600.

[0057] <Other Embodiments> As shown in Figure 10, it is preferable that the tip of the holder 505 that rubs against the protrusions 680a and 681a at the opposing wall portions 580 and 581 is bent upward in the vertical direction by a bending process such as hemming, forming a curved shape. This suppresses the generation of foreign matter caused by the metal holder 505 scraping the cleaning portion 601 when it rubs during the cleaning operation. However, depending on the shape of the holder 505 and manufacturing constraints, it may be difficult to form the part of the holder 505 that rubs against the protrusions 680a and 681a in the curved shape described above. In such cases, as shown in Figure 11, a sealing member 571 as a lubricating member may be placed between the holder 505 (more specifically the lower end of the opposing wall portions 580 and 581) and the protrusions 680a and 681a. This also suppresses the generation of foreign matter caused by the cleaning portion 601 being scraped during the cleaning operation. The sealing member 571 may be provided along the entire length of the lower end of the opposing wall portions 580, 581, or it may be provided on the protruding portions 680a, 681a.

[0058] The cleaning unit 601 may be detachably attached to the rod-shaped body 603. The procedure for attaching the cleaning unit 601 to the rod-shaped body 603 will be briefly explained using Figures 12(a) to 12(d). First, before attaching the cleaning unit 601 to the rod-shaped body 603, as shown in Figure 12(a), the cleaning blade 606 is inserted into the hole 608 provided in the cleaning unit 601 and fixed in place. Then, as shown in Figures 12(b) and 12(c), the cleaning unit 601 is rotated relative to the rod-shaped body 603 with the front side in the insertion direction as the pivot point. When the cleaning unit 601 is rotated relative to the rod-shaped body 603, the upper end of the cleaning blade 606 that protrudes upward from the cleaning unit 601 is housed in the recess 609a provided in the tip 609 of the rod-shaped body 603. Then, as shown in Figure 12(d), the snap-fit ​​portion 610 provided on the cleaning portion 601 engages with the engaged portion of the rod-shaped body 603, thereby fixing the cleaning portion 601 to the rod-shaped body 603. Note that not only the cleaning portion 601, but also the gripping portion 602 may be detachably provided on the rod-shaped body 603.

[0059] In the embodiments described above, the cleaning unit 601 is shown having side wall portions 680, 681 with protrusions 680a, 681a formed at both ends in the width direction, but it is not limited to this. For example, as shown in Figure 13, the cleaning unit 601 may have a so-called cantilever configuration in which a side wall portion 680 has a protrusion 680a formed only at one end in the width direction. However, in the case of a cantilever configuration, it becomes difficult to restrict the movement of the cleaning unit 601 in the left-right direction with only the cantilever side wall portion 680, and the cleaning unit 601 is more likely to detach from the holder 505 when moving. Therefore, especially in the case of a cantilever configuration, it is preferable to provide a restricting member 691 on the main body side of the device to restrict the movement of the cleaning unit 601 in the width direction. This restricting member 691 may be provided on the drum unit 518 as shown in the figure, or on the developing unit 641 (see Figure 2(a)). Of course, even if the cleaning section 601 has side wall sections 680 and 681 with protrusions 680a and 681a formed at both ends in the width direction, the restricting member 691 may still be provided. Also, in the case of a cantilever configuration, a restricting wall section 690 shorter in length than the side wall section 680 may be provided on the other end of the cleaning section 601 in the width direction, facing the cantilever side wall section 680. In the example shown in Figure 13, the restricting wall section 690 can contact the opposing wall section 581 of the holder 505 to restrict the movement of the cleaning section 601 in the left-right direction.

[0060] Although the image forming apparatus 1 of this embodiment is not shown in the figure, it is also applicable to an image forming apparatus of the so-called "top exposure method" in which the photosensitive drums 103Y, 103M, 103C, and 103K are exposed from above by the exposure units 520Y, 520M, 520C, and 520K. Furthermore, the image forming apparatus 1 is not limited to a full-color image apparatus equipped with multiple image forming units 102Y, 102M, 102C, and 102K as shown in Figure 1, but may also be a monochrome image apparatus equipped with, for example, only one black image forming unit 102K. [Explanation of Symbols]

[0061] 1…Image forming apparatus, 1A…Apparatus body, 103 (103Y~103K)…Photosensitive drum, 502…Substrate, 503…Light-emitting element (LED), 505…Holder, 506…Lens array, 507…Lens, 571…Lubricating member (sealing member), 580…Opposite wall section (first opposite wall section), 581…Opposite wall section (second opposite wall section), 582…Support section, 600…Cleaning member, 601…Cleaning section, 603…Rod-shaped body, 606…Sliding member (cleaning blade), 680 (681)…Regulating section (side wall section), 680a (681a)…Regulating section (protruding section), 690…Regulating wall section

Claims

1. a substrate having a plurality of light-emitting elements that emit light; a lens array having a plurality of lenses that focus the light emitted from the light-emitting elements onto the surface of a photosensitive drum; and a metal holder having a support portion that supports the lens array with the light-emitting surface of the lens array exposed on the side where the photosensitive drum is disposed, and two opposing wall portions that face each other in a width direction that intersects with the optical axis direction of the lenses and extend from the support portion toward the opposite side from the side where the photosensitive drum is disposed, the cleaning member being provided so as to be freely insertable into and removable from an image forming apparatus, a rod-shaped bar; a cleaning unit having a rubbing member for rubbing the light exit surface, the cleaning unit being provided on the rod-shaped body and being inserted into the image forming apparatus together with the rod-shaped body; When the cleaning unit is inserted into the image forming apparatus and moves together with the rod-shaped body, the cleaning unit has a restricting portion that abuts against the tip of each of the opposing wall portions from the side opposite to the arrangement side of the holder in the optical axis direction, and restricts movement of the cleaning unit in the direction away from the light exit surface in the optical axis direction, with the rubbing member rubbing against the light exit surface. A cleaning member characterized by:

2. The restricting portion has two side wall portions provided opposite to the opposing wall portions in the width direction, and a protruding portion protruding inward from each of the side wall portions so as to abut against a tip end of each of the opposing wall portions from below in the vertical direction.

2. The cleaning member according to claim 1.

3. a lubricating member is disposed between the protrusion and the tip of the opposing wall portion; 3. The cleaning member according to claim 2.

4. The holding body is bent upward in the vertical direction at a tip of the opposing wall portion.

3. The cleaning member according to claim 1 or 2.

5. The rubbing member is a flexible blade.

5. The cleaning member according to claim 1, wherein the cleaning member is a flexible member.

6. The cleaning unit is detachably provided on the rod-shaped body.

6. The cleaning member according to claim 1, wherein the cleaning member is a cleaning member having a first surface and a second surface.

7. a substrate having a plurality of light-emitting elements that emit light; a lens array having a plurality of lenses that focus the light emitted from the light-emitting elements onto the surface of a photosensitive drum; and a metal holder having a support portion that supports the lens array by exposing the light-emitting surface of the lens array on the side where the photosensitive drum is disposed, and having a first opposing wall portion and a second opposing wall portion that face each other in a width direction that intersects with the optical axis direction of the lenses and extend from the support portion toward the opposite side to the side where the photosensitive drum is disposed, the cleaning member being provided so as to be freely insertable into and removable from an image forming apparatus, a rod-shaped bar; a cleaning unit having a rubbing member for rubbing the light exit surface, the cleaning unit being provided on the rod-shaped body and being inserted into the image forming apparatus together with the rod-shaped body; the cleaning unit has a restricting portion that restricts movement of the cleaning unit in a direction away from the light exit surface in the optical axis direction by abutting against a tip of the first opposing wall portion from the side opposite to the arrangement side of the holder in the optical axis direction while the rubbing member is rubbing against the light exit surface when the cleaning unit is inserted into the image forming apparatus and moves together with the rod-shaped body. A cleaning member characterized by:

8. The regulating portion has a side wall portion provided opposite the first opposing wall portion in the width direction, a protruding portion protruding inward from the side wall portion so as to abut against a tip end of the first opposing wall portion from below in the vertical direction, and a regulating wall portion provided opposite the second opposing wall portion and regulating movement of the cleaning portion in the width direction.

8. The cleaning member according to claim 7.

Images