Optical scanner and image formation device

Abstract

To remove foreign objects, such as dust and toners, which adhere to a dust-proof member included in an optical scanner easily.SOLUTION: An optical scanner 3 includes: an emission port 110 which is provided at a housing 101 to emit a laser beam imaged by an optical member group to a photosensitive drum 5; and a dust-proof plate 108 which covers the emission port 110. The optical scanner 3 scans the photosensitive drum 5 with the deflected laser beam. The dust-proof plate 108 has: a base surface 108a; and a plurality of protruding parts 108b provided on the base surface 108a. When a distance between a center part of the protruding part 108b and a center part of a protruding part 108b adjacent to the protruding part as seen in a longitudinal direction of the dust-proof plate 108 is referred to as a pitch P, the protruding part 108b has a height H from the base surface 108a which is larger than the pitch P.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an optical scanning device and an image forming apparatus, and more particularly to an optical scanning device used in, for example, a copying machine, a printer, a facsimile machine, etc., that scans a surface to be scanned with a laser beam, and an image forming apparatus equipped with this optical scanning device. [Background technology]

[0002] The housing of an optical scanning device is provided with an opening (exit port) through which laser light passes to be irradiated onto a photosensitive drum (surface to be scanned). To prevent dust, toner, and the like from entering the optical scanning device through this opening, it is known to provide a dustproof member (transparent member) on the housing of the optical scanning device to cover the opening. Furthermore, a configuration has been proposed in which a mechanism is provided to clean dust or toner that has adhered to the dustproof member, thereby preventing degradation of image quality due to the dust or toner (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-044229 Summary of the Invention [Problem to be solved by the invention]

[0004] However, it is difficult to completely remove dust and toner adhering to the dustproof member, and to do so requires either strongly pressing a cleaning member against the dustproof member and rubbing it, or repeating the cleaning operation multiple times. Pressing the cleaning member firmly against the dustproof member requires increasing the rigidity of the cleaning member to provide strength, which increases costs. Furthermore, repeated cleaning operations require the dustproof member and cleaning member to be durable, which requires the use of high-strength components, which increases costs.

[0005] The present invention has been made under these circumstances, and an object of the present invention is to easily remove foreign matter such as dust and toner adhering to a dustproof member of an optical scanning device. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the present invention has the following configuration.

[0007] (1) An optical scanning device for deflecting and scanning the laser light onto the scanned body, comprising: a light source for emitting laser light; a deflection means for deflecting and scanning the laser light; a group of optical elements for forming an image of the laser light deflected and scanned by the deflection means; a housing that accommodates the deflection means and the group of optical elements; an opening provided in the housing for emitting the laser light imaged by the group of optical elements onto the scanned body; and a light-transmitting member that covers the opening, wherein the light-transmitting member has a base surface and a plurality of convex portions provided on the base surface, and when the distance between the center of a convex portion and the center of a convex portion adjacent to the convex portion in the longitudinal direction of the light-transmitting member is defined as the spacing between the convex portions, the height of the convex portions from the base surface is greater than the spacing.

[0008] (2) An image forming apparatus comprising: a photosensitive member as the scanned body; an optical scanning device as described in (1) that scans a laser beam corresponding to image information onto the photosensitive member to form an electrostatic latent image; a developing device that develops the electrostatic latent image formed on the photosensitive member with toner to form a developer image; and a transfer means that transfers the developer image onto a recording material. [Effects of the Invention]

[0009] According to the present invention, foreign matter such as dust and toner adhering to a dustproof member of an optical scanning device can be easily removed. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic cross-sectional view showing the configuration of an image forming apparatus equipped with an optical scanning device according to first and second embodiments. [Figure 2]Schematic diagram showing the configuration of an optical scanning device according to first and second embodiments. [Figure 3] FIG. 1 is a schematic perspective view showing the configuration of an optical scanning device according to first and second embodiments. [Figure 4] Enlarged cross-sectional view of the dustproof member of Example 1 [Figure 5] FIG. 1 is an enlarged cross-sectional view illustrating the configuration of a dustproof member according to a first embodiment. [Figure 6] Schematic diagram showing the uneven structure of Example 1 [Figure 7] FIG. 1 is an enlarged cross-sectional view illustrating the effect of the dustproof plate of the first embodiment. [Figure 8] Schematic cross-sectional view of an image forming apparatus according to a first embodiment [Figure 9] Schematic diagram showing a cleaning mechanism of Example 2 [Figure 10] Schematic diagram illustrating a cleaning mechanism according to a second embodiment. [Figure 11] FIG. 10 is a schematic diagram illustrating a cleaning mechanism according to a modified example of the second embodiment. DETAILED DESCRIPTION OF THE INVENTION [Example]

[0011] The configuration of a first embodiment of an image forming apparatus equipped with an optical scanning device according to the present invention will be described with reference to Figures 1 to 8. Note that the dimensions, materials, shapes, relative positions, etc. of the components described in the following embodiment are not intended to limit the scope of the present invention unless otherwise specified.

[0012] <Image forming device> The configuration of an image forming apparatus 1 will be described with reference to FIG. 1. FIG. 1 is a schematic cross-sectional view of the image forming apparatus 1 of the first embodiment. The image forming apparatus 1 is an electrophotographic color image forming apparatus that forms a toner image on a recording material 2 using four colors of toner (developers): yellow (Y), magenta (M), cyan (C), and black (K). The image forming apparatus 1 includes an optical scanning device 3. Light beams Lk, Lc, Lm, and Ly, each optically modulated based on image information, are emitted from the optical scanning device 3. These light beams illuminate the surfaces of photosensitive drums 5k, 5c, 5m, and 5y, which are photosensitive bodies uniformly charged by chargers 4k, 4c, 4m, and 4y, respectively, to form electrostatic latent images. The electrostatic latent images formed on the surfaces of the photosensitive drums 5k, 5c, 5m, and 5y, which are also scanned bodies, are visualized into black, cyan, magenta, and yellow toner images (developer images) by developing devices 6k, 6c, 6m, and 6y, respectively. The visualized toner images are transferred onto the transfer belt 7 at the nip portions between the transfer belt 7 and the photosensitive drums 5k, 5c, 5m, and 5y so that the black, cyan, magenta, and yellow toner images are superimposed (primary transfer).

[0013] Meanwhile, a recording material 2 placed on a feed tray is fed by a feed roller 8 and conveyed to a nip between a transfer belt 7 and a transfer roller 9 serving as a transfer means. The toner image that has been primarily transferred onto the transfer belt 7 is transferred onto the recording material 2 by the transfer roller 9 to form a color image (secondary transfer). The unfixed color image formed on the recording material 2 is heated and fixed by a fixing device 10 having an internal heater, and then discharged to the outside of the apparatus by discharge rollers 11 or the like.

[0014] <Optical scanning device> 2 and 3, the configuration of the optical scanning device 3 will be described. Fig. 2(a) is a schematic top view showing the configuration of the optical scanning device 3. Fig. 2(b) is a schematic cross-sectional view showing the configuration of the optical scanning device 3.

[0015] The optical scanning device 3 of the first embodiment is a unit mounted in a tandem color image forming apparatus, and is fixed to the frame of the image forming apparatus 1 described above by fixing members such as springs and screws (not shown). In the following description, for convenience, the scanning optical systems corresponding to each color will be referred to as the Y station, M station, C station, and K station. Because the configuration and optical function of the Y station and M station are the same as those of the C station and K station, the following description will focus on the Y station and M station. The suffixes y, m, c, and k at the end of the following reference numerals represent yellow, magenta, cyan, and black, respectively, and may be omitted if the color is not specified.

[0016] The light beam Ly emitted from the semiconductor laser 111y is substantially parallelized by a collimator lens 112y and enters a cylindrical lens 113y. The substantially parallel light beam that entered the cylindrical lens 113y exits as a parallel light beam in the main scanning cross section, the amount of light is limited by an aperture stop 114y, and the light beam is deflected by a scanner motor 103 equipped with a rotating polygonal mirror 102 as a deflection means. The deflected light beam Ly passes through a first scanning lens 105y, has its optical path deflected by a folding mirror 107y, and passes through a second scanning lens 106y and a dustproof plate 108y as a light-transmitting member, thereby being scanned at a constant speed while forming a spot on the photosensitive drum 5y. In the Y station, the light beam Ly is incident on a beam detector (hereinafter referred to as BD) 116y, which outputs a signal (hereinafter referred to as BD signal) to a control unit (not shown), and the control unit controls the writing position of the light beam Lm (described later) in the main scanning direction based on the BD signal. The semiconductor laser 111y and BD 116y are mounted on a substrate 115y.

[0017] A light beam Lm emitted from a semiconductor laser 111m arranged alongside the semiconductor laser 111y similarly passes through a collimator lens 112m, a cylindrical lens 113m, and an aperture stop 114m. The light beam Lm is then deflected by a different surface adjacent to the surface that deflects the light beam Ly of the rotating polygon mirror 102. In the M station, the light beam Lm does not enter the BD 116y.

[0018] The deflected light beam Lm passes through a first scanning lens 105m, a folding mirror 107m, a second scanning lens 106m, and a dustproof plate 108m before being guided to a photosensitive drum 5m. The dustproof plates 108y and 108m, which are dustproof members, are transparent members and prevent toner that has fallen from the developing unit 6 or the transfer belt 7 and dust that has entered from the outside from entering the optical scanning device 3. In the optical scanning device 3, a substrate 115 is attached to the outer side of a side surface of a housing 101, and the above-mentioned optical members such as lenses and mirrors, and a scanner motor 103 are attached inside the housing 101.

[0019] (dustproof plate) FIG. 3 is a schematic perspective view of the optical scanning device 3. The optical scanning device 3 has exit apertures 110y, 110m, 110c, and 110k (see FIG. 2(b)) as openings through which the light beams Ly, Lm, Lc, and Lk are emitted. Dustproof plates 108y, 108m, 108c, and 108k are attached to the exit apertures 110y, 110m, 110c, and 110k, respectively. The dustproof plate 108 in the first embodiment is a long resin plate, and is fixed to the optical scanning device 3 with an adhesive such as double-sided tape, adhesive, or hot melt. The dustproof plate 108 may also be attached with an elastic member such as a spring. Attaching the dustproof plate 108 to the exit aperture 110 substantially seals the interior of the optical scanning device 3, thereby preventing contamination of optical components such as the lenses and folding mirrors described above. The dustproof plate 108 is arranged so that its longitudinal direction is aligned with the direction in which the light beam L is scanned by the rotating polygon mirror 102, i.e., the longitudinal direction of the optical component group (hereinafter referred to as the scanning direction, main scanning direction, etc.).

[0020] <Dustproof plate configuration> Next, a characteristic configuration of Example 1 will be described with reference to Fig. 4. Fig. 4 is an enlarged cross-sectional view of dustproof plate 108. Dustproof plate 108 has a base surface 108a, and a plurality of fine protrusions 108b are provided on base surface 108a. In Example 1, the height H of protrusions 108b in this fine protrusion structure is 0.5 µm, the width D of protrusions 108b is 0.2 µm, and the pitch P, which is the distance between the centers (central portions) of adjacent protrusions 108b, is 0.4 µm. The structure of dustproof plate 108 in Example 1 is referred to as uneven structure 109.

[0021] The height H, width D, and pitch P of the protrusions 108b are preferably 1 μm or less, and the width of the protrusions 108b is preferably equal to or less than the wavelength of the laser used. However, the height H, width D, and pitch P of the protrusions 108b are not limited to these ranges, and it is sufficient if the shape of the protrusions 108b can minimize the contact area with particles such as powders (e.g., toner) and dust.

[0022] <Slide effect> Next, the powder sliding effect will be explained using Figures 5(a) to 5(c). Figures 5(a) to 5(c) illustrate the relationship between the powder and uneven structures 109a to 109c having various heights H and pitches P. Note that the size of the convex portions is exaggerated in the figures for the purpose of explanation.

[0023] 5(a) shows the relationship between the dustproof plate 108 and the powder 120 when the concave-convex structure 109a has protrusions 108b with height H, width D, and pitch P of 1 μm or less. As shown in FIG. 5(a), if the height H, width D, and pitch P of the protrusions 108b are within the above-mentioned ranges, the contact points between the surface of the dustproof plate 108 and the powder 120 are limited to the tips 108ba of the protrusions 108b, and the contact area with the powder 120 is reduced. Therefore, the adhesive force of the powder 120 is also reduced, and a sliding effect can be achieved.

[0024] Fig. 5(b) shows the relationship between the dustproof plate 108 and the powder 120 when the pitch P of the convex portions 108b is extremely small compared to the powder. As shown in Fig. 5(b), when the pitch P of the convex portions 108b is extremely small, the number of contact points between the powder 120 and the uneven structure 109b increases, reducing the ability of the powder 120 to slide down.

[0025] 5(c) shows the relationship between the dustproof plate 108 and the powder 120 in the case of the concave-convex structure 109c in which the pitch P of the convex portions 108b is larger than that of the powder. As shown in FIG. 5(c), if the pitch P is larger than that of the powder, the powder 120 will get into the recesses formed between the convex portions 108b and the convex portions 108b adjacent to each other, reducing the ability of the powder 120 to slide down. For this reason, it is preferable that the pitch P of the convex portions 108b be 1 μm or less (P≦1 μm), taking into account the size of powder such as toner and dust.

[0026] FIG. 5(d) shows the relationship between the dustproof plate 108 and the powder 120 when the uneven structure 109d has a height H of the convex portions 108b that is significantly smaller than the pitch P. As shown in FIG. 5(d), even when the height H of the convex portions 108b is shallower (smaller) than the pitch P, the number of contact points between the powder 120 and the uneven structure 109d increases. For this reason, it is preferable that the height H of the convex portions 108b be greater than the pitch P of the convex portions 108b (H>P). Furthermore, although not shown, if the width D of the convex portions 108b is increased, the contact area between the powder and the uneven structure similarly increases, reducing the ability of the powder to slide down. For this reason, it is preferable that the width D of the convex portions be equal to or less than half the pitch P (D≦1 / 2P).

[0027] <Uneven structure> 6(a) to 6(c) are diagrams showing the shapes of the convex portions when a plurality of convex portions spaced apart from one another are provided on the base surface 108a. FIG. 6(a) is a diagram showing a cylindrical convex portion 108bb. The diameter of the bottom surface of the cylindrical convex portion 108bb corresponds to the width D in FIG. 4, and the height H and diameter (width D) of the cylinder may be within the above-mentioned range. Furthermore, in the longitudinal cross sections of the dustproof plate 108, i.e., the EE cross section and the GG cross section, the interval between adjacent cylinders (convex portions 108bb) corresponds to the pitch P described in FIG. 4, and the pitch P may be within the above-mentioned range. Furthermore, in the KK cross section, which is a cross section of the dustproof plate 108 in a direction intersecting the longitudinal direction, the pitch P may also be within the above-mentioned range. Note that the cross section of the dustproof plate 108 in a direction intersecting the longitudinal direction may be a cross section other than the KK cross section. In FIG. 6(a), a plurality of convex portions 108bb spaced apart from one another are arranged two-dimensionally.

[0028] 6(b) is a diagram showing stripe-shaped protrusions 108bc formed by repeating rib shapes. The rib-shaped protrusions 108bc may have a height H and width D within the above-mentioned ranges. Furthermore, in a longitudinal cross section of the dustproof plate 108, i.e., cross section II, the interval between adjacent protrusions 108bc corresponds to the pitch P described in FIG. 4, and it is sufficient that the pitch P be within the above-mentioned range.

[0029] Furthermore, any shape can be selected, such as a conical protrusion 108bd as shown in FIG. 6(c). The diameter of the bottom surface of the conical protrusion 108bd corresponds to the width D in FIG. 4, and the height H and diameter (width D) of the cone may be within the above-mentioned range. Furthermore, in a longitudinal cross section of the dustproof plate 108, i.e., a JJ cross section, the distance between the apexes of adjacent cones (protrusions 108bb) corresponds to the pitch P described in FIG. 4, and the pitch P may be within the above-mentioned range. Furthermore, the pitch P may also be within the above-mentioned range in a cross section of the dustproof plate 108 in a direction intersecting the longitudinal direction, such as the KK cross section in FIG. 6(a). The cross section of the dustproof plate 108 in a direction intersecting the longitudinal direction may be a cross section other than the KK cross section. In FIG. 6(c), multiple protrusions 108bd are arranged two-dimensionally, separated from one another.

[0030] In this way, it is sufficient that the uneven structure has a shape that minimizes contact with the powder. The dustproof plate 108 of Example 1 is made of resin, and preferably made of cycloolefin polymer (COP), acrylic (PMMA), or the like. Thermoplastic materials such as polystyrene, polycarbonate, polypropylene, and polyethylene may also be used for the dustproof plate 108. Alternatively, the dustproof plate 108 may be made of a material such as glass, and a film may be formed on the surface of the material such as glass, with the uneven structure provided on the film.

[0031] (Regarding the manufacturing of uneven structures) The fine uneven structure made of resin is transferred to the surface of the molded product by providing an uneven structure on the core mold of a typical injection molding. A laser processing machine is used to process the uneven structure on the core mold, and laser light is emitted onto the core mold to form the uneven structure with each pulse. For example, infrared light with a wavelength of 1064 nm and a femtosecond pulse width is used, but other lasers can also be used.

[0032] When forming a film on a material such as glass and providing the film with a concave-convex structure, the glass surface may be coated with polysilazane or the like, and a mold having a fine concave-convex structure may be pressed against the film to transfer the structure.

[0033] <Installing the dustproof plate> Next, the mounting configuration of the dustproof plate 108 will be described with reference to Fig. 7. Fig. 7 is a cross-sectional view of the dustproof plate 108 in the short direction (direction perpendicular to the longitudinal direction), and is an enlarged cross-sectional view showing a state in which powder 120 such as toner has fallen onto the dustproof plate 108. The dustproof plate 108 is installed at an angle θ with respect to the horizontal direction. In the first embodiment, the dustproof plate 108 is installed at an angle θ with respect to the housing 101 of the optical scanning device 3 which is installed horizontally, but it may also be installed at an angle θ = 0° with respect to the optical scanning device 3, and the optical scanning device 3 itself may be installed at an angle with respect to the horizontal.

[0034] Since the dustproof plate 108 is installed at an inclination (angle θ), particles such as powder 120 such as toner that cannot be held by the developing device 6 or the like and fall do not remain on the dustproof plate 108 but slide down due to their own weight (arrow F). In addition, by providing a groove-shaped retention portion 121 (groove portion) in the housing 101 that retains the powder 120 such as toner or dust that has slid down, the risk of the powder 120 moving to another location and causing a malfunction can be reduced.

[0035] More specifically, one end in the short direction of the dustproof plate 108 is defined as end 108a1, and the other end in the short direction is defined as end 108a2. As a result, when the dustproof plate 108 is viewed in the longitudinal direction, as shown in Fig. 7, the end 108a2 is higher than the end 108a1, and the retention section 121 is provided on the end 108a1 side (the lower end).

[0036] <Fan> Next, a configuration for further suppressing adhesion of foreign matter on the dustproof plate 108 will be described with reference to FIG. 8. FIG. 8 is a schematic cross-sectional view of the image forming apparatus 1, with reference numerals assigned to essential parts. The image forming apparatus 1 has a fan 130 as a blower that serves both to cool and clean the interior of the apparatus. The fan 130 is provided primarily to cool electrical components that are likely to affect operation and performance during printing operations, as well as components that are likely to deteriorate due to temperature increases. The fan 130 may also be provided to clean areas that may become contaminated with dust, paper powder, toner, etc., causing image defects and the like. In the first embodiment, the image forming apparatus 1 is provided with the fan 130 for the latter cleaning purpose as well.

[0037] The fan 130 generates an air flow Dw. Note that the image forming apparatus 1 may be provided with a duct (not shown) that is a guide means, thereby forming an air path that guides the air flow Dw generated by the fan 130 onto each dustproof plate 108 through the duct or the like, and guiding the air flow Dw. By forming the air flow Dw above the dustproof plate 108, even if toner, dust, etc. do not completely slide down onto the dustproof plate 108 and remain, it can be removed with a light airflow.

[0038] In FIG. 7, the powder 120 falls onto the dustproof plate 108, slides down the dustproof plate 108 in the direction of arrow F under its own weight, and accumulates in the accumulation portion 121. For example, if the fan 130 is located on the opposite side from the position shown in FIG. 8, i.e., on the left side, the air flow will be opposite to that shown in FIG. 8. In this case, the powder 120 can move against the direction of gravity on the dustproof plate 108 from the lower end 108a1 to the higher end 108a2. Therefore, when the dustproof plate 108 is viewed in the longitudinal direction, the accumulation portion 121 may be provided on the side of the end 108a2 that is higher than the end 108a1 (the higher end).

[0039] As described above, this configuration prevents foreign matter such as toner and dust from adhering to the optical path of the optical scanning device, thereby providing a high-quality image forming device that is free from image defects caused by the adhesion of foreign matter. As described above, according to the first embodiment, foreign matter such as dust and toner adhering to the dustproof member of the optical scanning device can be easily removed. [Example]

[0040] Next, a configuration of an image forming apparatus according to a second embodiment of the present invention will be described. Components configured similarly to those in the first embodiment will be given the same reference numerals, or even if the reference numerals are different, the same component names will be used and the description will be omitted.

[0041] <Dustproof plate cleaning mechanism> 9, a configuration for further suppressing adhesion of foreign matter on the dustproof plate 108 by a means different from the method shown in FIG. 8 of the first embodiment will be described. FIG. 9 is a schematic diagram showing a cleaning mechanism for cleaning foreign matter when it adheres to the dustproof plate 108. FIG. 9(a) is a top view, and FIG. 9(b) is a cross-sectional view.

[0042] A cleaning unit 200 serving as a cleaning member is in contact with the dustproof plate 108, and is held by a holding unit 201. More specifically, the cleaning unit 200 is in contact with the surface of the dustproof plate 108 on which the concave-convex structure 109 is provided. The cleaning unit 200 is also provided at an angle α with respect to the longitudinal direction (arrow A). Therefore, one end 201a of the cleaning unit 200 in the short direction of the dustproof plate 108 and the other end 201b are located at different positions in the longitudinal direction of the dustproof plate 108.

[0043] The holder 201 can be slid in the longitudinal direction (arrow A) of the dustproof plate 108 by a drive mechanism 300 that is a drive means for driving the holder 201. Because of the angle α described above, when the holder 201 moves in the direction of arrow A, the end 201b precedes the end 201a. The cleaning part 200 in the second embodiment is preferably made of nonwoven fabric, felt, sponge, or the like.

[0044] <Dustproof plate cleaning operation> Next, the cleaning operation will be described with reference to Fig. 10. Fig. 10(a) shows the state before the dustproof plate 108 is cleaned, with powder 120 such as toner (black dots) remaining on the dustproof plate 108. Fig. 10(b) shows the state during cleaning, with the cleaning unit 200 moving together with the holding unit 201 in the direction of arrow A, and the cleaning unit 200 proceeding while scraping off the powder 120 such as toner (black dots).

[0045] At this time, the cleaning unit 200 is not perpendicular to the direction of arrow A but intersects with the dustproof plate 108 at an angle α, so that the scraped toner is discharged in the direction of arrow B. Incidentally, by providing the accumulation portion 121 described with reference to FIG. 7 in the direction of arrow B, the risk of the powder 120 moving to another location and causing a malfunction can be reduced. Thus, the cleaning unit 200 is provided at an angle α with respect to the longitudinal direction in order to move the scraped powder 120 to the accumulation portion 121, i.e., in the direction of arrow B. More specifically, the cleaning unit 200 is provided at angle α so that, when moving in the direction of arrow A, the end 201b of the cleaning unit 200 farther from the accumulation portion 121 in the lateral direction advances ahead of the end 201a of the cleaning unit 200 closer to the accumulation portion 121 in the lateral direction. The holding unit 201 may be provided at an angle so that the end 201a advances ahead of the end 201b when moving in the direction of arrow A. In this case, the accumulation portion 121 may be provided on the end 201b side.

[0046] Furthermore, the cleaning unit 200 in the second embodiment has a structure in which fibers such as nonwoven fabric are entangled, so that the cleaning unit 200 can entangle any toner that cannot be completely spit out. In the second embodiment, the dustproof plate 108 has the aforementioned fine convex shape (concave-convex structure 109), so that foreign matter such as toner and dust is less likely to adhere to the dustproof plate 108. Therefore, the cleaning unit 200 made of fibers such as nonwoven fabric can achieve sufficient cleaning performance with a biasing force that is just enough to slightly contact the dustproof plate 108. Furthermore, by tilting the installation angle (angle α) of the cleaning unit 200 with respect to the traveling direction, it is possible to achieve a scraping effect in a direction perpendicular to the traveling direction. This eliminates the need for a biasing member to strongly bias the cleaning unit 200 against the dustproof plate 108, and allows for a cleaning mechanism with an inexpensive configuration.

[0047] (Modification of Example 2) Next, a modified example of the cleaning mechanism described in the second embodiment will be described with reference to FIG. 11. The difference from FIG. 10 is the configuration of the cleaning unit 202 as the cleaning means. The cleaning unit 202 in FIG. 11 is made of a material such as rubber and functions as a blade. Elastic rubber, graphite, silicone rubber, etc. are preferable as blades, but resin can also be used instead. In the second embodiment, the cleaning unit 202 is driven in the direction of arrow A by a drive mechanism 300.

[0048] 11(a) shows the state before the dustproof plate 108 is cleaned, with toner (black dots) remaining on the dustproof plate 108. FIG. 11(b) shows the state during cleaning, with the cleaning unit 202 moving in the direction of arrow A, scraping away powder 120 such as toner (black dots) as it moves forward. At this time, the tip 202a of the cleaning unit 202 intersects with the dustproof plate 108 at an angle β rather than perpendicular to the direction of arrow A, so that the scraped-out toner is expelled in the direction of arrow B. More specifically, the tip 202a of the cleaning unit 202 in the moving direction (direction of arrow A) forms an angle β with the direction of arrow A.

[0049] When cleaning part 202 moves in the longitudinal direction, tip 202a is not perpendicular to the longitudinal direction in a plane parallel to dustproof plate 108. If angle β is less than 10°, powder 120 is not easily discharged in the direction of arrow B, so the tip angle of the blade is preferably 10° or more (β≧10°). Note that by providing accumulation part 121 described in FIG. 7 in the direction of arrow B, the risk of powder 120 moving to another location and causing a problem can be reduced.

[0050] More specifically, tip 202a of cleaning part 202 is angled β so that end 202a2, which is farther from accumulating part 121 in the short side direction, advances ahead of end 202a1, which is closer to accumulating part 121 in the short side direction, when cleaning part 202 advances in the direction of arrow A. Note that an angle may be set so that end 202a1 advances ahead of end 202a2 when cleaning part 202 advances in the direction of arrow A. In this case, accumulating part 121 may be provided on the end 202a2 side.

[0051] By using a blade cleaning mechanism, in this modified example, the dustproof plate 108 has the aforementioned fine convex shape (concave-convex structure 109), which makes it difficult for foreign matter such as toner and dust to adhere to the dustproof plate 108. Therefore, the blade cleaning unit 200 can achieve sufficient cleaning performance with a biasing force that just brings it into slight contact with the dustproof plate 108. Furthermore, by tilting the installation angle (angle β) of the cleaning unit 202 with respect to the direction of travel, it is possible to achieve the effect of scraping out the powder 120 in a direction perpendicular to the direction of travel. This eliminates the need for a biasing member to strongly bias the cleaning unit 202 against the dustproof plate 108, making it possible to realize a cleaning mechanism with an inexpensive configuration.

[0052] According to this configuration, it is possible to reduce the adhesion of dust and toner to the optical scanning device or to make cleaning easier after adhesion, thereby providing an image forming device that suppresses deterioration of image quality due to the adhesion of foreign matter such as dust and toner. As described above, according to the second embodiment, foreign matter such as dust and toner adhering to the dustproof member of the optical scanning device can be easily removed.

[0053] The disclosure of this embodiment includes the following configuration. (Configuration 1) a light source that emits laser light; a deflection means for deflecting and scanning the laser light; an optical member group for forming an image using the laser light deflected and scanned by the deflection means; a housing that houses the deflection means and the optical member group; an opening provided in the housing for emitting the laser light focused by the optical member group to a scanned object; a light-transmitting member covering the opening; an optical scanning device for deflectively scanning a laser beam onto the scanned object, the light-transmitting member has a base surface and a plurality of convex portions provided on the base surface, When the distance between the center of a convex portion and the center of a convex portion adjacent to the convex portion in the longitudinal direction of the light-transmitting member is defined as the interval between the convex portions, The optical scanning device is characterized in that the height of the convex portion from the base surface is greater than the interval. (Configuration 2) 2. The optical scanning device according to configuration 1, wherein the width of the convex portion in the longitudinal direction is equal to or less than half of the interval. (Configuration 3) 3. The optical scanning device according to claim 1, wherein the gap is 1 μm or less. (Configuration 4) 4. The optical scanning device according to any one of configurations 1 to 3, wherein the convex portion is a plurality of convex portions that are separated from each other and arranged two-dimensionally. (Configuration 5) the protrusion has a rib shape extending in a direction perpendicular to the longitudinal direction, 4. The optical scanning device according to any one of configurations 1 to 3, wherein the light-transmitting member has stripe-shaped convex portions in which the convex portions are repeatedly arranged in the longitudinal direction. (Configuration 6) 6. The optical scanning device according to any one of configurations 1 to 5, wherein the light-transmitting member is made of resin. (Configuration 7) a photosensitive member that is the scanned body; an optical scanning device according to any one of configurations 1 to 6, which scans a laser beam corresponding to image information onto the photosensitive member to form an electrostatic latent image; a developing device that develops the electrostatic latent image formed on the photosensitive member with toner to form a developer image; a transfer means for transferring the developer image onto a recording material; An image forming apparatus comprising: (Configuration 8) 8. The image forming apparatus according to configuration 7, wherein the translucent member is disposed such that, when viewed from the longitudinal direction, the transverse direction thereof is inclined relative to the horizontal direction. (Configuration 9) 9. The image forming apparatus according to configuration 8, wherein the light-transmitting member has a groove extending along the longitudinal direction on one of two ends in the lateral direction. (Configuration 10) 10. The image forming apparatus according to claim 9, wherein the groove is disposed on the side of the end having a lower height from the horizontal direction out of the two ends. (Configuration 11) A blowing means; a guide means for guiding the air generated by the air blowing means to the light-transmitting member; 11. The image forming apparatus according to any one of configurations 7 to 10, comprising: (Configuration 12) a cleaning member that comes into contact with the light-transmitting member and cleans the light-transmitting member; a driving means for driving the cleaning member to move in the longitudinal direction; Equipped with 12. The image forming apparatus of any one of Configurations 7 to 11, wherein the tip of the cleaning member when moving in the longitudinal direction is not perpendicular to the longitudinal direction in a plane parallel to the light-transmitting member. (Configuration 13) 13. The image forming apparatus according to claim 12, wherein the tip is disposed at an angle of 10 degrees or more with respect to the longitudinal direction within the plane. (Configuration 14) a cleaning member that comes into contact with the light-transmitting member and cleans the light-transmitting member; a driving means for driving the cleaning member to move in the longitudinal direction; Equipped with the cleaning member has a leading side and a trailing side in the longitudinal direction when moving in the longitudinal direction, 12. The image forming apparatus according to any one of configurations 7 to 11, wherein the groove is disposed on the trailing side. [Explanation of symbols]

[0054] 3 Optical scanning device 108 Dustproof plate 108a base surface 108b Convex part H Height of the convex part Pitch

Claims

1. a light source that emits laser light; a deflection means for deflecting and scanning the laser light; an optical member group for forming an image using the laser light deflected and scanned by the deflection means; a housing that houses the deflection means and the optical member group; an opening provided in the housing for emitting the laser light focused by the optical member group to a scanned object; a light-transmitting member covering the opening; an optical scanning device for deflectively scanning a laser beam onto the scanned object, the light-transmitting member has a base surface and a plurality of convex portions provided on the base surface, When the distance between the center of a convex portion and the center of a convex portion adjacent to the convex portion in the longitudinal direction of the light-transmitting member is defined as the interval between the convex portions, The optical scanning device is characterized in that the height of the convex portion from the base surface is greater than the interval.

2. 2. The optical scanning device according to claim 1, wherein the width of the convex portion in the longitudinal direction is equal to or less than half of the interval.

3. 2. The optical scanning device according to claim 1, wherein the interval is 1 [mu]m or less.

4. 2. The optical scanning device according to claim 1, wherein the convex portion comprises a plurality of convex portions that are separated from each other and are arranged two-dimensionally.

5. the protrusion has a rib shape extending in a direction perpendicular to the longitudinal direction, 2. The optical scanning device according to claim 1, wherein the light-transmitting member has stripe-shaped convex portions in which the convex portions are repeatedly arranged in the longitudinal direction.

6. 2. The optical scanning device according to claim 1, wherein the light-transmitting member is made of resin.

7. a photosensitive member that is the scanned body; an optical scanning device according to any one of claims 1 to 6, wherein a laser beam corresponding to image information is scanned onto the photosensitive member to form an electrostatic latent image; a developing device that develops the electrostatic latent image formed on the photosensitive member with toner to form a developer image; a transfer means for transferring the developer image onto a recording material; An image forming apparatus comprising:

8. 8. The image forming apparatus according to claim 7, wherein the translucent member is disposed such that a lateral direction of the translucent member is inclined with respect to a horizontal direction when viewed in the longitudinal direction.

9. 9. The image forming apparatus according to claim 8, wherein the light-transmitting member has a groove extending along the longitudinal direction on one of two ends in the lateral direction.

10. 10. The image forming apparatus according to claim 9, wherein the groove is disposed on the side of the end having a lower height from the horizontal direction out of the two end portions.

11. A blowing means; a guide means for guiding the air generated by the air blowing means to the light-transmitting member; 8. The image forming apparatus according to claim 7, further comprising:

12. a cleaning member that comes into contact with the light-transmitting member and cleans the light-transmitting member; a driving means for driving the cleaning member to move in the longitudinal direction; Equipped with 8. The image forming apparatus according to claim 7, wherein the tip of the cleaning member when moving in the longitudinal direction is not perpendicular to the longitudinal direction within a plane parallel to the light-transmitting member.

13. 13. The image forming apparatus according to claim 12, wherein the tip is disposed in the plane at an angle of 10 degrees or more with respect to the longitudinal direction.

14. a cleaning member that comes into contact with the light-transmitting member and cleans the light-transmitting member; a driving means for driving the cleaning member to move in the longitudinal direction; Equipped with the cleaning member has a leading side and a trailing side in the longitudinal direction when moving in the longitudinal direction, The image forming apparatus according to claim 9 , wherein the groove is disposed on the trailing side.

Images