Image formation apparatus

Abstract

To provide an image formation apparatus.SOLUTION: An image formation apparatus comprises a photoconductor having a photosensitive layer on a conductive support and rotating, and a cleaning member that removes toner adhering to a surface of the photoconductor. The photoconductor has a creep value of 4.5 or greater when a maximum load of 30 mN is applied to its surface under an environment of a temperature of 25°C and a relative humidity of 50%. The cleaning member includes a blade that scrapes toner adhering to the surface of the photoconductor and a paddle member that scoops up toner scraped from the surface of the photoconductor by the blade. The blade is in contact with the photoconductor at a position inclined at an angle of 5° or more and less than 30° on the downstream side in the rotational direction of the photoconductor relative to the highest point of the photoconductor, and an angle formed between the blade and the outer peripheral surface of the photoconductor is 5° or more and less than 20°. The paddle member has a paddle shaft and a blade member, and a hollow is provided in the blade member.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an image forming apparatus. [Background technology]

[0002] An image forming apparatus using an electrophotographic method includes a charging device that uniformly charges the surface of a photosensitive member acting as an image carrier; an exposure device that irradiates the surface of the photosensitive member with light based on image information to form an electrostatic latent image; a developing device that visualizes the electrostatic latent image using a developer; a transfer device that transfers the visualized toner image on the photosensitive member to the surface of a printing paper; a cleaning device that removes toner that remains on the surface of the photosensitive member but has not transferred to the printing paper; and a fixing device that fixes the toner image on the printing paper by applying heat and pressure.

[0003] In image forming apparatuses, cleaning blades are widely used as a means for removing toner from the surface of a photoreceptor. For example, Patent Document 1 discloses a cleaning device equipped with a cleaning blade that removes toner from the surface of a photoreceptor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-18004 Summary of the Invention [Problem to be solved by the invention]

[0005] When cleaning with a blade, one of the factors that causes a photoreceptor to reach the end of its life is wear of the photosensitive layer on the outermost surface of the photoreceptor. To extend the life of the photoreceptor, it is necessary to improve the wear resistance of the photosensitive layer on the surface of the photoreceptor. Increasing the hardness of the photoreceptor improves the wear resistance of the photoreceptor, but on the other hand, the amount of the photoreceptor that can be scraped off decreases, which reduces cleaning performance and makes filming more likely to occur.

[0006] In such a case, when the same image pattern is printed continuously, the amount of toner remaining between the cleaning blade and the photosensitive member becomes uneven in the axial direction of the photosensitive member, and toner, paper dust, etc. slip through the blade and adhere to the photosensitive member unevenly in the axial direction of the photosensitive member, resulting in differences in developability between the areas where the toner has adhered and the areas where it has not, resulting in the problem of streaks appearing in the printed image that do not exist in the image data.In particular, when the cleaning device is located above the photosensitive member, the remaining toner is likely to accumulate near the blade, making streaks more likely to appear in the printed image. An object of the present disclosure is to provide an image forming apparatus that extends the life of a photoreceptor and suppresses the occurrence of streaks in printed images. [Means for solving the problem]

[0007] An image forming apparatus according to one embodiment of the present disclosure includes a rotating photoreceptor having a photosensitive layer on a conductive support, and a cleaning member that removes toner adhering to the surface of the photoreceptor, wherein the photoreceptor has a creep value of 4.5 or more when a maximum load of 30 mN is applied to the surface in an environment of a temperature of 25°C and a relative humidity of 50%, and the cleaning member includes a blade that scrapes off toner adhering to the surface of the photoreceptor, and a paddle member that scoops up the toner scraped off from the surface of the photoreceptor by the blade, wherein the blade abuts against the photoreceptor at a position inclined at an angle of 5° or more and less than 30° downstream in the rotational direction of the photoreceptor from the highest point of the photoreceptor, and the angle formed between the blade and the outer peripheral surface of the photoreceptor is 5° or more and less than 20°, and the paddle member has a paddle shaft and a blade member, and the blade member has a cavity. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic cross-sectional view showing an image forming apparatus according to the present disclosure. [Figure 2] FIG. 1 is a schematic perspective view showing a photosensitive member and a cleaning unit according to a first embodiment of the present disclosure. [Figure 3] 1 is a schematic cross-sectional view showing a photoreceptor and a cleaning unit according to a first embodiment of the present disclosure. [Figure 4] FIG. 2 is a schematic cross-sectional view showing details of the positional relationship between the photosensitive member and the blade according to the first embodiment of the present disclosure. [Figure 5] FIG. 10 is a plan view showing a paddle member according to a second embodiment of the present disclosure. [Figure 6] FIG. 10 is a plan view illustrating an example of a cavity according to a second embodiment of the present disclosure. [Figure 7] FIG. 10 is a plan view showing a paddle member according to a modified example of the second embodiment of the present disclosure. [Figure 8] FIG. 10 is a plan view showing a paddle member according to a third embodiment of the present disclosure. [Figure 9] FIG. 10 is a plan view showing a paddle member according to a fourth embodiment of the present disclosure. [Figure 10] 1A and 1B are printed images corresponding to four levels in the streak evaluation of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present disclosure will be described below with reference to the drawings. In the drawings, identical or equivalent elements are designated by the same reference numerals, and redundant explanations will be omitted. Furthermore, the present disclosure and the embodiments of the present disclosure described below do not unduly limit the content of the present disclosure described in the claims, and not all of the configurations described in the embodiments are necessarily essential as means for solving the problems of the present disclosure.

[0010] <Image forming device> 1 is a schematic cross-sectional view showing the internal structure of an image forming apparatus 100 according to the present disclosure. The image forming apparatus 100 is, for example, a printing machine having a printer function, and forms a multicolor or monochrome image on printing paper by electrophotography. Note that the image forming apparatus 100 according to the present disclosure is not limited to a printing machine, and may be a multifunction machine having a copying function, a printer function, a scanner function, a facsimile function, etc.

[0011] The image forming apparatus 100 includes, for example, a main body 101, which is a housing that houses each of the components constituting the image forming apparatus 100. The main body 101 includes a paper feed tray 102, a charging device 103, an exposure device 104, a developing device 105, a photoconductor 200, a cleaning unit 300, a transfer roller 106, a static eliminator 107, a fixing unit 108, a paper discharge roller 109, a paper discharge tray 110, and the like.

[0012] As will be described in detail later, photoreceptor 200 includes cylindrical conductive support 201 having electrical conductivity and photosensitive layer 202 provided on the peripheral surface of conductive support 201. Photoreceptor 200 has a rotation shaft (not shown) along its axis, and is rotated in a first rotation direction around the rotation shaft by an electric motor (not shown). The charging device 103 charges the photosensitive layer 202 on the peripheral surface of the photosensitive member 200 to a predetermined potential.

[0013] The exposure device 104 irradiates light to expose the photosensitive layer 202 on the peripheral surface of the charged photoreceptor 200. Based on the data of the image to be printed, the exposure device 104 irradiates the photosensitive layer 202 with light to form an image based on the image data. The charged photosensitive layer 202 is exposed to the light irradiated by the exposure device 104, and an electrostatic latent image corresponding to the image data is formed on the photosensitive layer 202.

[0014] The developing device 105 supplies toner onto the photosensitive layer 202 on the circumferential surface of the photosensitive member 200 and develops the electrostatic latent image on the photosensitive layer 202 to form a toner image. This disclosure illustrates an image forming apparatus 100 that prints monochrome images, and is configured with a photosensitive member corresponding to black, an exposure device, and a developing device. Note that this disclosure is not limited to image forming apparatuses 100 that print monochrome images, but can also be applied to image forming apparatuses 100 that print full-color images.

[0015] Transfer roller 106 is a member that transfers the toner image on photoreceptor 200 to printing paper. Printing paper supplied from paper feed tray 102 passes between photoreceptor 200 and transfer roller 106. As the printing paper passes between photoreceptor 200 and transfer roller 106, the toner image formed on photoreceptor 200 is transferred to one side of the printing paper.

[0016] The toner image transferred to the printing paper is fixed to the printing paper by being heated and pressed by the fixing unit 108, which includes a heating roller, a pressure roller, etc. As described above, the image forming apparatus 100 prints an image on the printing paper. The print paper on which the image has been printed is transported from the fixing unit 108 by a paper discharge roller 109 toward a paper discharge tray 110 and is discharged onto the paper discharge tray 110 .

[0017] The static eliminator 107 eliminates the charge on the photosensitive layer 202 on the circumferential surface of the photoreceptor 200 after the toner image has been transferred, thereby enabling the residual toner remaining on the surface of the photosensitive layer 202 to be removed from the surface of the photosensitive layer 202 after the toner image has been transferred to the printing paper.

[0018] The cleaning unit 300 removes the remaining toner from the photosensitive layer 202 on the circumferential surface of the photosensitive element 200 after neutralization. As will be described in detail later, the cleaning unit 300 includes a blade 301 that contacts the photosensitive layer 202, and cleans the photosensitive element 200 by scraping off the remaining toner from the photosensitive layer 202 with the blade 301. During this process, the photosensitive layer 202 on the circumferential surface of the photosensitive element 200 is scraped and worn away by the blade 301. Furthermore, some of the remaining toner remains between the photosensitive element 200 and the blade 301 as old toner, which acts to reduce the frictional force between the photosensitive element 200 and the blade 301.

[0019] The cleaned photoconductor 200 is again charged by the charging device 103, exposed by the exposure device 104, and then supplied with new toner by the developing device 105. As described above, the image forming apparatus 100 continuously prints images while replacing the toner on the circumferential surface of the photoconductor 200.

[0020] <Embodiment 1> Fig. 2 is a schematic perspective view showing the photoreceptor 200 and the cleaning unit 300 according to the first embodiment of the present disclosure. Fig. 3 is a schematic cross-sectional view showing the photoreceptor 200 and the cleaning unit 300 according to the first embodiment of the present disclosure. Fig. 3 is a cross-sectional view taken along a plane perpendicular to the rotation axis of the photoreceptor 200 in the circumferential direction.

[0021] <Photoreceptor> The photoreceptor 200 includes a cylindrical conductive support 201 that rotates around a rotation axis in a first rotation direction and a photosensitive layer 202 provided on the outer peripheral surface of the conductive support 201. For example, in FIG. 3, the first rotation direction is counterclockwise. The conductive support 201 is a conductive support that functions as an electrode for the photoreceptor 200 and as a support member for the photosensitive layer 202. It is formed of, for example, a metal such as aluminum, copper, zinc, or titanium, or an alloy such as stainless steel. The conductive support 201 may also be formed by laminating a metal foil on the surface of a cylindrical polymer material, glass, hard paper, or the like, or by vapor-depositing or coating a metal material or a conductive compound on the surface. To prevent interference fringes caused by laser light, the surface of the conductive support 201 may be subjected to a diffuse reflection treatment, such as an anodized film treatment, a surface treatment using chemicals or hot water, a coloring treatment, or a surface roughening treatment, within a range that does not affect image quality.

[0022] The photosensitive layer 202 generally has a two-layer structure consisting of a charge generation layer laminated on the conductive support 201 and a charge transport layer laminated on the charge generation layer. The charge generation layer has the function of absorbing light irradiated from the exposure device 104 and generating charges, and is, for example, a resin layer containing a charge generation material. Examples of the charge generation material include azo pigments such as monoazo pigments, bisazo pigments, and trisazo pigments; indigo pigments such as indigo and thioindigo; perylene pigments such as perylene imide and perylene anhydride; polycyclic quinone pigments such as anthraquinone and pyrenequinone; metal phthalocyanines such as titanyl phthalocyanine; phthalocyanine pigments such as metal-free phthalocyanine; organic photoconductive materials such as squarylium dyes, pyrylium salts, thiopyrylium salts, and triphenylmethane dyes; and inorganic photoconductive materials such as selenium and amorphous silicon. These charge generating materials may be used alone or in combination of two or more. The thickness of the charge generating layer is not particularly limited, but is preferably 0.05 μm to 5 μm, more preferably 0.1 μm to 1 μm. If the thickness of the charge generating layer is less than 0.05 μm, the efficiency of light absorption may decrease, and the sensitivity of the photoreceptor may decrease. On the other hand, if the thickness of the charge generating layer exceeds 5 μm, charge transfer within the charge generating layer may become the rate-limiting step in the process of erasing the charge on the surface of the photoreceptor, and the sensitivity of the photoreceptor may decrease.

[0023] The charge transport layer is a layer that has the function of receiving the charges generated by the charge generating material and transporting them to the surface of the photoreceptor 200, and is, for example, a resin layer containing a charge transport material. Examples of charge transport materials that can be used include carbazole derivatives, pyrene derivatives, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazolidine derivatives, bisimidazolidine derivatives, styryl compounds, hydrazone compounds, polycyclic aromatic compounds, indole derivatives, pyrazoline derivatives, oxazolone derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, triarylamine derivatives, triarylmethane derivatives, phenylenediamine derivatives, stilbene derivatives, butadiene derivatives, enamine derivatives, benzidine derivatives, polymers having groups derived from these compounds in the main chain or side chain (such as poly-N-vinylcarbazole, poly-1-vinylpyrene, ethylcarbazole-formaldehyde resin, triphenylmethane polymer, and poly-9-vinylanthracene), and polysilanes. These charge transport materials may be used alone or in combination of two or more. The thickness of the charge transport layer is not particularly limited, but is preferably 5 μm to 50 μm, more preferably 10 μm to 40 μm. If the thickness of the charge transport layer is less than 5 μm, the charge retention ability of the photoreceptor surface may decrease. On the other hand, if the thickness of the charge transport layer exceeds 50 μm, the resolution of the photoreceptor may decrease. A surface protection layer may be further provided on the photosensitive layer 202.

[0024] An intermediate layer (not shown) may be provided between the conductive support 201 and the photosensitive layer 202. The intermediate layer is formed of a resin material such as polyamide resin, and smoothes the surface of the conductive support 201 to improve the film-forming properties of the photosensitive layer 202 and also improves the adhesion between the conductive support 201 and the photosensitive layer 202. This prevents charge from being injected from the conductive support 201 into the photosensitive layer 202, prevents a decrease in the chargeability of the photosensitive layer 202, and prevents image fogging.

[0025] <Creep value> The creep value of the photoreceptor 200 is measured using a microhardness tester. For example, the creep value of the photoreceptor 200 is measured using a microhardness tester by applying a maximum indentation load of 30 mN for 5 seconds using a Vickers square pyramid diamond indenter with an opposing angle of 136° in an environment of 25°C temperature and 50% relative humidity. Specifically, the creep value C (%) of the photoreceptor 200 is calculated by the formula: creep value C = 100 × (h2 - h1) / h1, where h1 is the depth to which the photoreceptor 200 is indented from its original shape when the maximum load of 30 mN is first reached, and h2 is the depth to which the photoreceptor 200 is indented from its original shape when the maximum load of 30 mN is maintained for 5 seconds.

[0026] The larger the creep value C, the greater the deformation of photoreceptor 200 while a load is applied. As a result, the load applied by blade 301 in contact with photoreceptor 200 can be appropriately alleviated by the deformation of photoreceptor 200, reducing the amount of wear on photosensitive layer 202 caused by blade 301 and extending the life of photoreceptor 200. The photoreceptor 200 of the present disclosure has a creep value of 4.5% or more, which allows the life of photoreceptor 200 to be long enough to not pose any problems in practical use of image forming apparatus 100.

[0027] <Cleaning section> The cleaning unit 300 includes a blade 301, a paddle member 400, and a conveying screw 303. The cleaning unit 300 is installed above the photoconductor 200.

[0028] <Blade> Blade 301 is installed so as to incline downwards toward photoreceptor 200, with its tip abutting against photoreceptor 200. Blade 301 scrapes off the toner 500 remaining on the circumferential surface of photoreceptor 200 after it has been transferred to printing paper, and transfers it to blade upper surface 302. During this process, photosensitive layer 202 on the circumferential surface of photoreceptor 200 is worn away by being scraped off by blade 301. Furthermore, some of the old toner 500 scraped off by blade 301 remains between photoreceptor 200 and blade 301, reducing friction between the photoreceptor 200 and blade 301.

[0029] <Blade contact position and blade angle relative to the photosensitive member> Fig. 4 is a schematic cross-sectional view showing in detail the positional relationship between the photoreceptor 200 and the blade 301 according to the first embodiment of the present disclosure. Fig. 4 is a cross-sectional view taken along a plane perpendicular to the circumferential direction of the rotation axis of the photoreceptor 200. In Fig. 4, the first rotation direction in which the photoreceptor 200 rotates is counterclockwise.

[0030] The position where blade 301 contacts photoconductor 200 is defined as follows. In FIG. 4 , highest point 203 of photoconductor 200 is located vertically above rotation center 204 of photoconductor 200. Blade 301 contacts photoconductor 200 downstream of highest point 203 in a first rotation direction, which is the direction of rotation of photoconductor 200. The position where blade 301 contacts photoconductor 200 is determined by the central angle θ1 formed by tangent point 205 between photoconductor 200 and blade 301, rotation center 204, and highest point 203. In other words, blade 301 contacts photoconductor 200 at a position inclined by angle θ1 downstream of highest point 203 in the first rotation direction. In the following description, the position where blade 301 contacts photoconductor 200 will also be referred to as blade position θ1.

[0031] In the present disclosure, the central angle θ1 that determines the blade position θ1 is an angle that is equal to or greater than 5° and less than 30°. If the blade position θ1 is less than 5°, the blade 301 is less able to remove the toner 500 from the photoreceptor 200, and old toner 500 is less likely to accumulate and be replaced, which can lead to streaks in the printed image. Furthermore, if the blade position θ1 is 30° or greater, the supply of toner 500 between the photoreceptor 200 and the blade 301 decreases, increasing the friction between the photoreceptor 200 and the blade 301. This can cause the blade 301 to bend and reverse in the first rotation direction, potentially making it impossible to remove the toner 500 from the photoreceptor 200. By setting the central angle θ1 that determines the blade position θ1 to an angle that is equal to or greater than 5° and less than 30°, it is possible to both suppress streaks in the printed image and maintain the toner removal function of the blade 301.

[0032] The angle formed between blade 301 and the outer peripheral surface of photoconductor 200 is defined as follows: In Fig. 4, the angle θ2 formed between blade 301 and the tangent line at contact point 205 between photoconductor 200 and blade 301 is the angle formed between blade 301 and the outer peripheral surface of photoconductor 200. In the following description, the angle formed between blade 301 and the outer peripheral surface of photoconductor 200 is also referred to as blade angle θ2.

[0033] In the present disclosure, the blade angle θ2 is an angle between 5° and 20°. If the blade angle θ2 is less than 5°, the ability of the blade 301 to remove the toner 500 decreases, the toner 500 tends to remain on the photoreceptor 200, the toner 500 is less likely to be replaced, and streaks tend to occur in the printed image. If the blade angle θ2 is 20° or greater, the supply of toner 500 between the photoreceptor 200 and the blade 301 decreases, the friction between the photoreceptor 200 and the blade 301 increases, and the blade 301 may be warped and reversed in the first rotation direction, making it impossible to remove the toner 500 from the photoreceptor 200. By setting the blade angle θ2 to an angle between 5° and 20°, it is possible to both suppress the occurrence of streaks in the printed image and maintain the toner removal function of the blade 301.

[0034] <Paddle parts> As shown in Figures 2 and 3, a paddle member 400 is installed above the blade upper surface 302. The paddle member 400 has a paddle shaft 401 that rotates around a rotation axis in a second rotation direction that is opposite to the first rotation direction, and four blade members 402 that are provided at equal intervals in the circumferential direction on the circumferential surface of the paddle shaft 401. One of the four blade members 402 is provided with a cavity 403. For example, in Figure 3, the second rotation direction is clockwise. The paddle member 400 can be molded from a material to which toner does not easily adhere, such as ABS resin.

[0035] The paddle member 400 moves the toner 500, which has been removed from the photoreceptor 200 by the blade 301 and moved to the blade upper surface 302, in a direction away from the photoreceptor 200 by the vane member 402 rotating clockwise, which is the second rotation direction. As shown in Figures 2 and 3, the vane member 402 moves the toner 500 on the blade upper surface 302 along the dotted arrow in the direction from the photoreceptor 200 side of the blade 301 toward the conveying screw 303. The toner 500 scraped up on the blade upper surface 302 by the vane member 402 is moved by the conveying screw 303 along the dotted arrow in the direction along the axial direction of the photoreceptor 200, as shown in Figure 2, and is discharged to a waste toner recovery unit (not shown) located outside the cleaning unit 300. 3, some of the toner 500 scraped up by the blade member 402 passes through the cavity 403 and returns to the side of the blade 301 closer to the photoconductor 200, and is resupplied between the photoconductor 200 and the blade 301. This expels some of the old toner 500 removed from the photoconductor 200 and promotes its replacement with new toner 500, thereby suppressing the occurrence of streaks in the printed image, while resupplying some of the old toner 500 between the photoconductor 200 and the blade 301, reducing friction between the photoconductor 200 and the blade 301 and extending the life of the photoconductor 200. The mechanism for discharging the toner 500 from the cleaning unit 300 is not limited to the conveying screw 303, but may be a conveyor, a conveying belt, or the like.

[0036] As described above, the creep value of photoreceptor 200, the blade position where photoreceptor 200 and blade 301 come into contact, the angle of blade 301, and blade member 402 with cavity 403 can extend the life of photoreceptor 200 and suppress the occurrence of streaks in printed images, thereby providing image forming apparatus 100 with stable image characteristics over a long period of time.

[0037] In the first embodiment, as shown in FIGS. 2 and 3 , the paddle member 400 includes four blade members 402. However, the present disclosure is not limited to this configuration, and the paddle member 400 may include at least one blade member 402 having a cavity 403. The number of blade members 402 may be any number. Furthermore, the number of blade members 402 having a cavity 403 does not need to be only one; multiple blade members 402 may have the cavity 403. By including multiple blade members 402 having a cavity 403, the amount of toner 500 resupplied between the photoconductor 200 and the blade 301 can be increased, and friction between the photoconductor 200 and the blade 301 can be further reduced, thereby further extending the life of the photoconductor 200.

[0038] In blade member 402, the ratio of the area occupied by cavity 403 to the total area of ​​blade member 402 is preferably 15% to 75%. If cavity 403 occupies less than 15%, the toner 500 scraped up by blade member 402 is less likely to be resupplied onto blade 301, increasing friction between photoconductor 200 and blade 301 and potentially shortening the life of photoconductor 200. On the other hand, if cavity 403 occupies more than 75%, the blade member 402's ability to scrape up toner 500 is reduced, making it more difficult to replace the toner 500. This makes it more likely that old toner 500 will adhere to photoconductor 200, potentially resulting in streaks in printed images. By setting the ratio of the area occupied by cavity 403 within the above range, a good balance can be achieved between the effect of extending the life of photoconductor 200 and the effect of suppressing streaks in printed images.

[0039] In the present disclosure, it is more preferable that the photosensitive layer 202 has a surface contact angle with water of 95° or more. The surface contact angle of the photosensitive layer 202 with water is determined by using a contact angle meter to measure the contact angle of water dropped on the surface of the photosensitive layer 202. If the surface contact angle of the photosensitive layer 202 is 95° or more, the surface of the photosensitive body 200 becomes slippery, the toner 500 is less likely to adhere to the surface of the photosensitive body 200, and the toner 500 is more easily removed by the blade 301, which makes it easier for the toner 500 to be replaced, further reducing the occurrence of streaks in the printed image.

[0040] In the present disclosure, the photosensitive layer 202 may contain a polycarbonate resin having both of the two structural units represented by the following chemical formula (1) and the following chemical formula (2): In the chemical formula, each of R1, R2, R3, and R4 is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 6 carbon atoms. TIFF2025163326000002.tif24162 TIFF2025163326000003.tif23162

[0041] Polycarbonate resins having both the structural units represented by the above-mentioned chemical formula (1) and the following chemical formula (2) have excellent abrasion resistance, which improves the durability of the photosensitive layer 202 and further extends the life of the photoreceptor 200.

[0042] In the present disclosure, the photosensitive layer 202 may contain fluororesin particles. For example, the charge transport layer contained in the photosensitive layer 202 may have a charge transport material and fluororesin particles dispersed in a resin layer serving as a base material. The inclusion of fluororesin particles improves the mechanical strength of the photosensitive layer 202, thereby extending the life of the photoreceptor 200. Materials for the fluororesin particles include polytetrafluoroethylene resin, polychlorotrifluoroethylene resin, polytetrafluoroethylenepropylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin, and polydichlorodifluoroethylene resin, with polytetrafluoroethylene resin being particularly preferred from the viewpoint of improving dispersibility.

[0043] In the present disclosure, the photosensitive layer 202 may contain inorganic particles. For example, the charge transport layer contained in the photosensitive layer 202 may have a charge transport material and inorganic particles dispersed in a resin layer serving as a base material. The inclusion of inorganic particles improves the mechanical strength of the photosensitive layer 202, thereby extending the life of the photoreceptor 200. Suitable materials for the inorganic particles include silicon dioxide and aluminum oxide.

[0044] In the present disclosure, the photosensitive layer 202 may contain a resin having a cross-linked structure. For example, in the charge transport layer included in the photosensitive layer 202, when the base resin is cured into a resin layer, a cross-linking reaction may be caused by adding a cross-linking agent or irradiating with electron beams to form a three-dimensional cross-linked structure. When the resin contains a cross-linked structure, the mechanical strength of the photosensitive layer 202 is improved, and the life of the photoreceptor 200 can be extended.

[0045] In the present disclosure, the toner 500 may contain fatty acid metal salt particles. The toner 500 containing fatty acid metal salt particles can be obtained, for example, by mixing silica particles, which are toner base particles, with zinc stearate particles, which are fatty acid metal salts, in a mixer. The fatty acid metal salt is a combination of a fatty acid and a metal, and may be a combination of a fatty acid such as stearic acid, lauric acid, ricinoleic acid, or octylic acid with a metal such as lithium, magnesium, calcium, barium, or zinc. Because fatty acid metal salts have a lubricating effect, the inclusion of fatty acid metal salt particles in the toner 500 reduces the frictional force generated in the toner 500. This reduces the frictional force between the photoreceptor 200 and the blade 301, further extending the life of the photoreceptor 200. Furthermore, the toner 500 is less likely to adhere to the photoreceptor 200, further reducing the occurrence of streaks in printed images.

[0046] <Photoreceptor Overview> For example, the photoreceptor 200 of the present disclosure includes a conductive support 201 and a photosensitive layer 202 formed on the conductive support 201. The photosensitive layer 202 is composed of one or more layers, and the surface layer of the photosensitive layer 202 contains a binder resin and a charge transport material. Furthermore, the photoreceptor 200 of the present disclosure may be a laminated photoreceptor (also referred to as a "function-separated photoreceptor") in which a photosensitive layer 202 having a laminated structure (also referred to as a "laminated photosensitive layer" or "function-separated photosensitive layer") is provided, in which an undercoat layer (not shown) is laminated on the conductive support 201, and a charge generation layer and a charge transport layer are laminated on the undercoat layer in this order. A protective layer (not shown) may also be provided on the charge transport layer. An example of a method for manufacturing the photoreceptor 200 of the present disclosure will be described below.

[0047] Materials for forming the conductive support 201 include metal materials such as aluminum, aluminum alloys, copper, zinc, stainless steel, and titanium; polymer materials (polyethylene terephthalate, nylon, polystyrene, etc.), glass, and hard paper, each laminated with a metal foil; materials on which a metal material is vapor-deposited; and materials on which a layer of a conductive compound such as a conductive polymer, tin oxide, or indium oxide is vapor-deposited or coated. Among these, aluminum or aluminum alloys are preferred in terms of ease of processing. The shape of the conductive support 201 is not limited to a cylindrical shape and may be a sheet, columnar, endless belt, or the like. Furthermore, the surface of the conductive support 201 may be subjected to anodizing treatment, surface treatment with chemicals or hot water, coloring, or diffuse reflection treatment such as surface roughening, as needed, to prevent interference fringes caused by laser light, as long as it does not affect image quality.

[0048] An undercoat layer is formed on the peripheral surface of the conductive support 201. The undercoat layer generally covers and smooths the surface irregularities of the conductive support 201, improves the film-forming properties of the photosensitive layer 202, suppresses peeling of the photosensitive layer 202 from the conductive support 201, and improves adhesion between the conductive support 201 and the photosensitive layer 202. Specifically, it prevents charge injection from the conductive support 201 to the photosensitive layer 202, prevents a decrease in the chargeability of the photosensitive layer 202, and prevents image fogging, or the occurrence of so-called black spots. The undercoat layer can be formed, for example, by dissolving a binder resin in a suitable solvent to prepare an undercoat layer coating solution, applying this coating solution to the surface of the conductive support 201, and drying to remove the organic solvent. Examples of binder resins include the same binder resins as those contained in the photosensitive layer 202 described below, as well as natural polymeric materials such as casein, gelatin, polyvinyl alcohol, and ethyl cellulose. These may be used alone or in combination. The binder resin is preferably a polyamide resin, particularly an alcohol-soluble nylon resin, because it must not dissolve or swell in the solvent used to form the photosensitive layer 202 on the undercoat layer, must have excellent adhesion to the conductive support 201, and must be flexible. Examples of alcohol-soluble nylon resins include homopolymer or copolymer nylons such as 6-nylon, 66-nylon, 610-nylon, 11-nylon, and 12-nylon, and chemically modified nylons such as N-alkoxymethyl-modified nylons. Examples of solvents that can dissolve or disperse the resin material include alcohols such as water, methanol, ethanol, and butanol; glymes such as methyl carbitol and butyl carbitol; chlorinated solvents such as dichloroethane, chloroform, and trichloroethane; acetone, dioxolane, and mixed solvents containing two or more of these solvents. Among these solvents, non-halogenated organic solvents are preferred for environmental reasons. The undercoat layer coating solution may also contain inorganic compound particles. The inorganic compound particles in the undercoat layer have a different purpose of being blended in from the inorganic compound particles contained in the photosensitive layer 202 described below, and may be the same compound or different compounds.The inorganic compound particles in the undercoat layer allow for easy adjustment of the volume resistivity of the undercoat layer, further suppressing charge injection into the photosensitive layer 202, and maintaining the electrical properties of the photoreceptor 200 under various environments. Examples of inorganic compound particles in the undercoat layer include titanium oxide, aluminum oxide, aluminum hydroxide, and tin oxide. The ratio of the total weight of the binder resin and the inorganic compound particles in the undercoat layer to the weight of the solvent in the undercoat layer coating solution is preferably 1 / 99 to 40 / 60, and more preferably 2 / 98 to 30 / 70. Furthermore, the ratio of the weight of the binder resin to the weight of the inorganic compound particles is preferably 90 / 10 to 1 / 99, and more preferably 70 / 30 to 5 / 95.

[0049] Known devices such as ball mills, sand mills, attritors, vibration mills, ultrasonic dispersers, and paint shakers may be used to disperse the inorganic compound particles in the undercoat layer coating solution. The coating method for the undercoat layer can be selected based on the physical properties and productivity of the coating solution. Examples include spraying, bar coating, roll coating, blade coating, ring coating, and dip coating. Among these, the dip coating method involves immersing a conductive support 201 in a coating tank filled with the coating solution and then lifting it at a constant or gradually changing speed to form a layer on the surface of the conductive support 201. This method is relatively simple and offers advantages in terms of productivity and cost, making it suitable for manufacturing photoreceptors 200. The dip coating device may be equipped with a coating solution dispersion device, such as an ultrasonic generator, to stabilize the dispersibility of the coating solution. In the drying process for the formed undercoat layer, the solvent in the coating film may be removed by natural drying or by heating. The temperature in the drying step is not particularly limited as long as it is a temperature at which the solvent used can be removed, but a temperature of approximately 50°C to 140°C is appropriate, and approximately 80°C to 130°C is particularly preferred. If the drying temperature is below 50°C, the drying time may be long and the solvent may not evaporate sufficiently and remain in the photosensitive layer. Furthermore, if the drying temperature exceeds 140°C, repeated use of the photoreceptor may deteriorate the electrical characteristics, resulting in deterioration of the resulting image. These temperature conditions are common not only to the formation of the undercoat layer but also to the formation of layers such as the photosensitive layer 202 described below and other processes.

[0050] The thickness of the undercoat layer is not particularly limited, but is preferably 0.01 μm to 20 μm, more preferably 0.05 μm to 10 μm. If the thickness of the undercoat layer is less than 0.01 μm, the undercoat layer will not substantially function as an undercoat layer, and it will be impossible to cover defects in the conductive support 201 to achieve a uniform surface, and there is a risk that it will not be possible to prevent charge injection from the conductive support 201 to the photosensitive layer 202. On the other hand, if the thickness of the undercoat layer exceeds 20 μm, it will be difficult to form a uniform undercoat layer, and there is a risk that the sensitivity of the photoreceptor 200 will also decrease. Note that when the conductive support 201 is made of aluminum, a layer containing alumite may be formed as the undercoat layer.

[0051] The thickness of the undercoat layer is not particularly limited, but is preferably 0.01 μm to 20 μm, more preferably 0.05 μm to 10 μm. If the thickness of the undercoat layer is less than 0.01 μm, the undercoat layer will not substantially function as an undercoat layer, and it will be impossible to cover defects in the conductive support 201 to achieve a uniform surface, and there is a risk that it will not be possible to prevent charge injection from the conductive support 201 to the photosensitive layer 202. On the other hand, if the thickness of the undercoat layer exceeds 20 μm, it will be difficult to form a uniform undercoat layer, and there is a risk that the sensitivity of the photoreceptor 200 will also decrease. Note that when the conductive support 201 is made of aluminum, a layer containing alumite may be formed as the undercoat layer.

[0052] The charge-generating layer, one of the layers constituting the photosensitive layer 202, generates charges by absorbing light irradiated by a semiconductor laser or the like in the image-forming apparatus 100. Its primary component is a charge-generating material, optionally containing a binder resin and additives. Examples of charge-generating materials include compounds commonly used in the art, such as azo pigments (e.g., monoazo pigments, bisazo pigments, and trisazo pigments); indigo pigments (e.g., indigo and thioindigo); perylene pigments (e.g., perylene imide and perylene anhydride); polycyclic quinone pigments (e.g., anthraquinone and pyrenequinone); phthalocyanine pigments (e.g., metal phthalocyanines such as titanyl phthalocyanine and metal-free phthalocyanines); organic photoconductive materials (e.g., squarylium dyes, pyrylium salts, thiopyrylium salts, and triphenylmethane dyes); and inorganic photoconductive materials (e.g., selenium and amorphous silicon). These charge-generating materials may be used singly or in combination. Among these charge-generating materials, titanyl phthalocyanine is preferred. Titanyl phthalocyanine is a charge-generating material that has high charge generation efficiency and charge injection efficiency in the emission wavelength range (near-infrared light) of currently commonly used laser light and LED light, and generates a large amount of charge by absorbing light, and can efficiently inject the generated charge into a charge-transporting material without accumulating it internally.

[0053] Methods for forming the charge generation layer include a method of vacuum-depositing a charge generation material onto the conductive support 201, and a method of dispersing a charge generation material in a solvent and coating the conductive support 201 with a coating liquid for the charge generation layer. Among these, a preferred method is to disperse the charge generation material in a binder resin solution obtained by mixing a binder resin in a solvent using a conventionally known method, and then coat the coating liquid for the charge generation layer on the conductive support 201 (on the undercoat layer). This method will be described below.

[0054] The binder resin is not particularly limited, and any resin known in the art can be used. Examples include polyester, polystyrene, polyurethane, phenolic resin, alkyd resin, melamine resin, epoxy resin, silicone resin, acrylic resin, methacrylic resin, polycarbonate, polyarylate, polyphenoxy, polyvinyl butyral, polyvinyl formal, and other resins, as well as copolymer resins containing two or more of the repeating units constituting these resins. Examples of copolymer resins include insulating resins such as vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride copolymer resin, and acrylonitrile-styrene copolymer resin. These resins may be used alone or in combination of two or more. Examples of the solvent include halogenated hydrocarbons such as dichloromethane and dichloroethane; ketones such as acetone, methyl ethyl ketone and cyclohexanone; esters such as ethyl acetate and butyl acetate; ethers such as tetrahydrofuran (THF) and dioxane; alkyl ethers of ethylene glycol such as 1,2-dimethoxyethane; aromatic hydrocarbons such as benzene, toluene and xylene; and aprotic polar solvents such as N,N-dimethylformamide and N,N-dimethylacetamide. These solvents may be used alone or in combination of two or more.

[0055] The compounding ratio of the charge generating substance to the binder resin is preferably such that the proportion of the charge generating substance is in the range of 10 to 99% by mass. If the proportion of the charge generating substance is less than 10% by mass, sensitivity may decrease. On the other hand, if the proportion of the charge generating substance exceeds 99% by mass, not only will the film strength of the charge generating layer decrease, but the dispersibility of the charge generating substance will decrease, resulting in an increase in coarse particles. This will reduce the surface charge in areas other than those that should be erased by exposure, and may result in image defects, particularly image fogging known as black spots, in which toner adheres to a white background and forms tiny black dots.

[0056] Before dispersing the charge generating material in the binder resin solution, the charge generating material may be pulverized in advance using a pulverizer. Examples of pulverizers used for pulverization include ball mills, sand mills, attritors, vibration mills, and ultrasonic dispersers. Examples of dispersers used to disperse the charge generating material in the binder resin solution include paint shakers, ball mills, and sand mills. Dispersion conditions at this time may be selected appropriately so as to prevent the incorporation of impurities due to wear of the container and components constituting the disperser. The coating method for the charge generating layer may be the same as the coating method for the undercoat layer, with dip coating being particularly preferred.

[0057] The thickness of the charge generation layer is not particularly limited, but is preferably 0.05 μm to 5 μm, more preferably 0.1 μm to 1 μm. If the thickness of the charge generation layer is less than 0.05 μm, the efficiency of light absorption may decrease, and the sensitivity of the photoreceptor may decrease. On the other hand, if the thickness of the charge generation layer exceeds 5 μm, charge transfer within the charge generation layer may become the rate-limiting step in the process of erasing the charge on the surface of the photosensitive layer 202, and the sensitivity of the photoreceptor 200 may decrease.

[0058] The charge transport layer, which is one of the layers constituting the photosensitive layer 202, has the function of receiving the charges generated by the charge generating substance and transporting them to the surface of the photoreceptor 200, and contains a charge transport substance, a binder resin, and, if necessary, additives. As the charge transport substance, compounds used in the relevant field can be used. Specific examples include carbazole derivatives, pyrene derivatives, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazolidine derivatives, bisimidazolidine derivatives, styryl compounds, hydrazone compounds, polycyclic aromatic compounds, indole derivatives, pyrazoline derivatives, oxazolone derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, triarylamine derivatives, triarylmethane derivatives, phenylenediamine derivatives, stilbene derivatives, butadiene derivatives, enamine derivatives, benzidine derivatives, polymers having groups derived from these compounds in the main chain or side chain (poly-N-vinylcarbazole, poly-1-vinylpyrene, ethylcarbazole-formaldehyde resin, triphenylmethane polymer, poly-9-vinylanthracene, etc.), and polysilanes. These charge transport materials may be used alone or in combination of two or more. A preferred method for forming the charge transport layer is to disperse the charge transport material and inorganic compound particles in a binder resin solution obtained by mixing a binder resin in a solvent by a known method, and then coat the coating liquid for the charge transport layer on the charge generating layer. This method is described below.

[0059] The binder resin is not particularly limited, and any resin known in the art can be used. Examples include vinyl polymer resins such as polymethyl methacrylate, polystyrene, and polyvinyl chloride, and copolymer resins thereof; polycarbonate, polyester, polyester carbonate, polysulfone, polyphenoxy, epoxy resin, silicone resin, polyarylate, polyphenylene oxide, polyamide, polyether, polyurethane, polyacrylamide, and phenolic resin. These binder resins may be used alone or in combination of two or more. Among these, polystyrene, polycarbonate, and polyarylate are particularly preferred because they have a volume resistivity of 10 Ω or more, excellent electrical insulation, and excellent film-forming properties and potential characteristics.

[0060] The ratio of charge transport material to binder resin is preferably 10 / 12 to 10 / 30. If the ratio is less than 10 / 30 and the binder resin ratio is high, the viscosity of the coating solution increases when the charge transport layer is formed by dip coating, resulting in a decrease in coating speed and significantly reduced productivity. Furthermore, if the amount of solvent in the coating solution is increased to suppress the increase in viscosity, blushing may occur, causing the formed charge transport layer to become cloudy. On the other hand, if the ratio exceeds 10 / 12 and the binder resin ratio is low, the printing durability may be reduced compared to when the binder resin ratio is high, and the amount of wear of the photosensitive layer 202 may increase.

[0061] The charge transport layer may have a crosslinked structure to enhance mechanical strength and improve electrical properties. Methods for creating a crosslinked structure include a formulation containing a curable binder resin and a method containing a charge transport agent having a crosslinkable functional group and a curable binder resin. The curable binder resin preferably contains a resin that forms a three-dimensional network structure by a crosslinking reaction, such as a resin containing at least one of an alkyd resin and a thermosetting acrylic resin and at least one of a guanamine resin and a melamine resin, a thermosetting polyurethane resin, or a curable siloxane resin formed by thermally crosslinking an organosilicon compound having either a hydroxyl group or a hydrolyzable group.

[0062] Examples of charge transport agents having crosslinkable functional groups include those having functional groups such as hydroxyl groups, mercapto groups, isocyanate groups, and amine groups. Crosslinking these with a binder resin can enhance mechanical strength. The charge transport layer may contain inorganic compound particles or fluorine-based particles to enhance mechanical strength and improve electrical properties. When the charge transport layer is a surface layer of the photosensitive layer 202, the content of the inorganic compound particles or fluorine-based resin particles is preferably 5% by mass or more and 25% by mass or less of the total solid content of the charge transport layer. Suitable inorganic compound particles include silica particles and alumina particles. Suitable fluorine-based resin particles include polytetrafluoroethylene resin, polychlorotrifluoroethylene resin, polytetrafluoroethylenepropylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin, and polydichlorodifluoroethylene resin. Among these, polytetrafluoroethylene particles containing polytetrafluoroethylene resin are preferred from the viewpoint of improving dispersibility.

[0063] The charge transport layer may contain additives such as plasticizers and leveling agents as needed to improve film-forming properties, flexibility, and surface smoothness. Examples of plasticizers include dibasic acid esters such as phthalates, fatty acid esters, phosphate esters, chlorinated paraffins, and epoxy-type plasticizers. Examples of leveling agents include silicon-based leveling agents. Examples of solvents include aromatic hydrocarbons such as benzene, toluene, xylene, and monochlorobenzene; halogenated hydrocarbons such as dichloromethane and dichloroethane; ethers such as THF, dioxane, and dimethoxymethyl ether; and aprotic polar solvents such as N,N-dimethylformamide. If necessary, additional solvents such as alcohols, acetonitrile, and methyl ethyl ketone can be used. Among these solvents, non-halogenated organic solvents are preferred for environmental reasons. These solvents may be used alone or in combination. The charge transport layer can be formed, for example, in the same manner as in the case of forming the charge generation layer described above, by preparing a coating liquid for the charge transport layer by dissolving or dispersing a charge transport material, a binder resin, and, if necessary, the additives described above in an appropriate solvent, and then applying this coating liquid onto the charge generation layer by a spray method, a bar coating method, a roll coating method, a blade method, a ring coating method, a dip coating method, etc. Among these coating methods, the dip coating method is particularly preferable for forming the charge transport layer because it is superior in various respects as described above.

[0064] The thickness of the charge transport layer is not particularly limited, but is preferably 5 μm to 50 μm, more preferably 10 μm to 40 μm. If the thickness of the charge transport layer is less than 5 μm, the charge retention ability of the surface of the photoreceptor 200 may decrease. On the other hand, if the thickness of the charge transport layer exceeds 50 μm, the resolution of the photoreceptor 200 may decrease.

[0065] A protective layer may be provided on the charge transport layer. The protective layer may contain one or more charge transport materials to stabilize electrical characteristics. The protective layer may contain a filler material to improve abrasion resistance. Examples of such filler materials include organic fillers such as fluororesin powders (e.g., polytetrafluoroethylene), silicone resin powders, and α-carbon powders; metal powders (e.g., copper, tin, aluminum, and indium); metal oxides (e.g., silica, tin oxide, zinc oxide, titanium oxide, indium oxide, antimony oxide, bismuth oxide, antimony-doped tin oxide, and tin-doped indium oxide); and inorganic fillers such as potassium titanate. Inorganic fillers are particularly preferred in terms of filler hardness. The thickness of the protective layer is not particularly limited, but is preferably 0.5 μm to 10 μm, and more preferably 1 μm to 7 μm.

[0066] <Embodiment 2> 5 is a plan view showing a paddle member 400 according to a second embodiment of the present disclosure. In the second embodiment, the blade member 402 has a plurality of cavities 403. In FIG. 5, for example, the blade member 402 has nine rectangular cavities 403 arranged in a row at equal intervals along the axial direction of the photoreceptor 200.

[0067] According to the configuration of the second embodiment, the toner 500 scraped up by the blade member 402 is mixed and then passed through each of the plurality of cavities 403 before being resupplied to the blade 301, which makes it easier for the amount of toner 500 between the photoreceptor 200 and the blade 301 to become uniform in the axial direction of the photoreceptor 200. This prevents some of the toner 500 from slipping through the blade 301 and remaining unevenly on the photoreceptor 200, further reducing the occurrence of streaks in the printed image.

[0068] In the blade member 402 of the second embodiment, the ratio of the total area of ​​the plurality of cavities 403 to the total area of ​​the blade member 402 is preferably 15% to 75%. If the ratio of the total area of ​​the plurality of cavities 403 is less than 15%, the toner 500 scraped up by the blade member 402 is less likely to be resupplied onto the blade 301, increasing friction between the photoreceptor 200 and the blade 301, which may shorten the life of the photoreceptor 200. On the other hand, if the ratio of the total area of ​​the plurality of cavities 403 is more than 75%, the blade member 402's ability to scrape up the toner 500 is reduced, making it more difficult to replace the toner 500, and old toner 500 is more likely to adhere to the photoreceptor 200, which may result in streaks in printed images. By setting the ratio of the total area within the above range, it is possible to achieve a good balance between the effect of extending the life of the photoreceptor 200 and the effect of suppressing the occurrence of streaks in printed images.

[0069] As shown in FIG. 6, the shape of the cavity 403 may be rectangular, round, hooked, or V-shaped, with no sides parallel to the end sides of the blade member 402, and the multiple cavities 403 provided in the blade member 402 may include a mixture of the above-mentioned types of shapes.

[0070] <Modification of the second embodiment> FIG. 7 is a plan view showing a modified example of the paddle member 400 according to the second embodiment of the present disclosure. In FIG. 7, a greater number of cavities 403 than those in FIG. 5 are provided in the blade member 402 and arranged in a mesh pattern. By increasing the number of cavities 403 and forming a mesh pattern, when the toner 500 passes through the cavities 403 and is resupplied to the blade 301, the amount of toner 500 between the photoreceptor 200 and the blade 301 tends to become more uniform in the axial direction of the photoreceptor 200. This further prevents some of the toner 500 from passing through the blade 301 and remaining unevenly on the photoreceptor 200, thereby further suppressing the occurrence of streaks in printed images.

[0071] In a modification of the second embodiment, the area of ​​each of the plurality of cavities 403 is 4 mm 2Over 16mm 2 It is preferable that the area of ​​each cavity 403 is 4 mm or less. 2 If the area is less than 16 mm, the toner 500 will have difficulty passing through the cavities 403, which may cause clogging and reduce the amount of toner 500 resupplied between the photoconductor 200 and the blade 301. In addition, in order to mix the toner 500 as it passes through the multiple cavities 403, the area of ​​each cavity 403 should be 16 mm 2 It is preferable to limit the amount of toner 500 passing through one cavity 403 as follows: The plurality of cavities 403 do not need to have the same shape or area, and one cavity may have a size of 4 mm or less. 2 Over 16mm 2 If it is within the following range, a better effect can be obtained.

[0072] <Embodiment 3> FIG. 8 is a plan view showing a paddle member 400 according to a third embodiment of the present disclosure. In the third embodiment, the blade member 402 has a first side 404 fixed to the paddle shaft 401 and a second side 405 closer to the blade 301. The blade member 402 is divided into two regions with a center line 406 between the first side 404 and the second side 405 as the boundary line. More specifically, the blade member 402 is divided into a first region 407 between the center line 406 and the first side 404, and a second region 408 between the center line 406 and the second side 405. In the third embodiment, the proportion of the area occupied by the cavities 403 in the first region 407 is larger than the proportion of the area occupied by the cavities 403 in the second region 408. In other words, the positions of the multiple cavities 403 in the blade member 402 of the second embodiment are closer to the paddle shaft 401.

[0073] In the third embodiment, by reducing the proportion of the area occupied by the cavity 403 in the second region 408 closer to the blade 301, the ability of the blade member 402 to scrape up the toner 500 is increased, making it easier to replace the toner 500 and further reducing the occurrence of streaks in the printed image. Also, by increasing the proportion of the area occupied by the cavity 403 in the first region 407 closer to the paddle shaft 401 and not reducing the area occupied by the cavity 403 in the entire blade member 402, the amount of toner 500 that is resupplied from the cavity 403 to the blade 301 is ensured, and the life of the photoconductor 200 can be maintained longer.

[0074] <Embodiment 4> FIG. 9 is a plan view showing a paddle member 400 according to a fourth embodiment of the present disclosure. In the fourth embodiment, the blade member 402 has a flexible brush portion 409 at a portion that contacts the photoreceptor 200. The brush portion 409 is formed of a flexible resin material, such as urethane resin. The brush portion 409 is provided at the tip of the blade member 402 and contacts the photoreceptor 200. When the brush portion 409 is flexed by the rotational force of the paddle member 400, the blade member 402 largely repels the toner 500 on the blade 301, facilitating replacement of the toner 500 and further reducing the occurrence of streaks in the printed image. As shown in FIG. 9 , a urethane sheet with notches or slits may be fixed to the blade member 402 to allow the brush portion 409 to flex easily. The notches at the tip repel toner around the blade, which has the effect of promoting replacement of toner, thereby further suppressing streak-like image defects. Furthermore, brush portion 409 is not limited to the structure shown in Fig. 9, and may have, for example, a bristle brush structure in which resin bristles are implanted in bristle implantation holes provided at the tip of vane member 402.

[0075] <Preparation of Photoreceptors Used in Examples 1 to 9 and 15 and Comparative Examples 1 to 4 and 6> The undercoat layer was prepared by adding 3 parts by weight of titanium oxide (manufactured by Ishihara Sangyo Kaisha, Ltd., product name: Typec® TTO-D-1) and 2 parts by weight of copolymer polyamide (nylon) (manufactured by Toray Industries, Inc., product name: Amilan®, grade: CM8000) to 25 parts by weight of methyl alcohol and dispersing the mixture for 8 hours using a paint shaker to prepare 3 liters of a coating solution for the undercoat layer. A coating tank was filled with the resulting coating solution for the undercoat layer, and an aluminum drum-shaped support (conductive support 201) with an outer diameter of 30 mm, an inner diameter of 28.4±0.03 mm, and a length of 340 mm was immersed therein and then removed. The resulting coating film was allowed to dry naturally to form a 1 μm-thick undercoat layer on the conductive support 201.

[0076] Oxotitanium phthalocyanine, represented by the structural formula shown below, was prepared in advance for use as a charge-generating material. 29.2 g of diiminoisoindoline and 200 ml of sulfolane were mixed, and 17.0 g of titanium tetraisopropoxide was added. The mixture was allowed to react for 2 hours at 140°C under a nitrogen atmosphere. After allowing the reaction mixture to cool, the precipitate was collected by filtration and washed sequentially with chloroform and 2% aqueous hydrochloric acid, then with water and methanol, and dried to yield 25.2 g of blue-purple crystals. Chemical analysis of the resulting compound confirmed it to be the oxotitanium phthalocyanine represented by the structural formula shown below (yield: 88.5%). One part by weight of the resulting titanyl phthalocyanine and one part by weight of butyral resin (Sekisui Chemical Co., Ltd., product name: S-LEC BM-2) were added to 98 parts by weight of methyl ethyl ketone and dispersed for 2 hours using a paint shaker to prepare 3 liters of a coating solution for the charge-generating layer.

[0077] The resulting charge-generating layer coating solution was applied onto the undercoat layer using the same dipping method as used for forming the undercoat layer. The resulting coating was then air-dried to form a charge-generating layer with a thickness of 0.3 μm. For example, a stilbene compound represented by the following structural formula, used as a charge-transport material, was prepared in advance according to the method described in Japanese Patent No. 3272257. 5 g of the resulting compound, 10 g of polyarylate resin (Mitsubishi Chemical Corporation, product name: E2-400), and 50 g of tetrahydrofuran were added to a 2 L PP container, mixed, and stirred for 15 hours using a ball mill (Eishin Co., Ltd., model: benchtop ball mill BM-15) to prepare 60 g of charge-transport layer coating solution. The resulting charge-transport layer coating solution was applied onto the charge-generating layer using a blade coating method. The resulting coating was then dried at 120°C for 1 hour to form a charge-transport layer with a thickness of 34 μm, yielding photoreceptor 200.

[0078] <Preparation of Photoreceptor Used in Example 10> Evaluation was carried out under the same conditions as in Example 1, except that a photoreceptor prepared by the following procedure was used as the charge transport layer of the photoreceptor: 5 g of a stilbene compound, 9.5 g of polyarylate resin (manufactured by Mitsubishi Chemical Corporation, product name: E2-400), 0.5 g of polycarbonate (manufactured by Idemitsu Kosan Co., Ltd., product name: EH203), and 45 g of tetrahydrofuran were mixed and stirred for 15 hours using a ball mill (manufactured by Eishin Co., Ltd., model: benchtop ball mill BM-15).

[0079] <Preparation of Photoreceptor Used in Example 11> Evaluation was carried out under the same conditions as in Example 1, except that a photoreceptor prepared as follows was used as the charge transport layer of the photoreceptor: 5 g of a stilbene compound, 10 g of polycarbonate resin (manufactured by Idemitsu Kosan Co., Ltd., product name: TZ7017), and 65 g of tetrahydrofuran were mixed and stirred for 15 hours using a ball mill (manufactured by Eishin Co., Ltd., model: benchtop ball mill BM-15).

[0080] <Preparation of Photoreceptor Used in Example 12> The evaluation was performed under the same conditions as in Example 1, except that a photoreceptor prepared as follows was used as the charge transport layer of the photoreceptor. 1.5 g of tetrafluoroethylene resin microparticles (PTFE, number average primary particle diameter: approximately 200 nm, manufactured by Daikin Industries, Ltd., product name: Lubron L-2) serving as fluororesin particles was heated in an oven at 150°C for 30 minutes. This suspension was then suspended in 0.11 g of a fluorine-based dispersant (GF-400, manufactured by Toa Gosei Co., Ltd.) and 14.5 g of tetrahydrofuran, and stirred for 30 hours using a stirrer (manufactured by Shibata Scientific Co., Ltd., model: M-103) and a stirring blade. 4.5 g of a stilbene compound, 9 g of a polyarylate resin (manufactured by Mitsubishi Chemical Corporation, product name: E2-400), and 36.6 g of tetrahydrofuran were added to the resulting solution as charge transport materials, mixed, and further stirred for 15 hours. The resulting mixture was subjected to a 5-pass dispersion treatment using a particle dispersion device (manufactured by Microfluidics, model: M-110P) to prepare a coating liquid for the charge transport layer.

[0081] <Preparation of Photoreceptor Used in Example 13> Evaluation was performed under the same conditions as in Example 1, except that a photoreceptor prepared as follows was used as the charge transport layer of the photoreceptor. 1.5 g of silica particles (manufactured by Nippon Aerosil Co., Ltd., product name: AEROSIL R972, number average primary particle diameter 16 nm, dimethyldichlorosilane surface treatment) was suspended in 13.5 g of tetrahydrofuran and stirred for 30 hours using a stirrer (manufactured by Shibata Scientific Co., Ltd., model: M-103) and a stirring blade. 4.5 g of a stilbene compound, 9.0 g of polyarylate resin (manufactured by Mitsubishi Chemical Corporation, product name: E2-400), and 36.6 g of tetrahydrofuran were added as charge transport materials to the resulting silica filler suspension, mixed, and further stirred for 15 hours. The resulting mixture was subjected to 10-pass dispersion treatment using a particle disperser (manufactured by Microfluidics, model: M-110P) to prepare a coating solution for the charge transport layer.

[0082] <Preparation of Photoreceptor Used in Example 14> The evaluation was carried out under the same conditions as in Example 1, except that a photoreceptor prepared as follows was used as the charge transport layer of the photoreceptor. A coating solution for the charge transport layer was prepared by dissolving 30 g of the compound of the following chemical formula (3), prepared by the method described in Japanese Patent No. 4011791, in a mixed solution of 15 g of monochlorobenzene and 15 g of methylene chloride. This coating solution was applied to the charge generation layer by blade coating, and then irradiated with an electron beam under conditions of an accelerating voltage of 150 kV and an irradiation dose of 10 Mrad in an atmosphere with an oxygen concentration of 10 ppm. The resulting product was then heat-treated at 100°C for 10 minutes to form a charge transport layer with a thickness of 18 μm, thereby obtaining a photoreceptor. TIFF2025163326000004.tif25162

[0083] <Preparation of Photoreceptor Used in Comparative Example 5> Evaluation was carried out under the same conditions as in Example 1, except that a photoreceptor prepared by the following procedure was used as the charge transport layer of the photoreceptor: 5 g of a stilbene compound, 8 g of polyarylate resin (manufactured by Mitsubishi Chemical Corporation, product name: E2-400), 2 g of polycarbonate (manufactured by Teijin Chemical Co., Ltd., product name: Panlite (registered trademark) TS2020), and 45 g of tetrahydrofuran were mixed and stirred for 15 hours using a ball mill (manufactured by Eishin Co., Ltd., model: benchtop ball mill BM-15).

[0084] <Preparation of Toners Used in Examples 1 to 14 and Comparative Examples 1 to 6> <Production Example 1: Preparation of amorphous polyester resin A> A 5-L reactor was charged with 440 g (2.7 mol) of terephthalic acid, 235 g (1.4 mol) of isophthalic acid, 7 g (0.05 mol) of adipic acid, 554 g (8.9 mol) of ethylene glycol, and 0.5 g of tetrabutoxy titanate as a polymerization catalyst. The mixture was reacted at 210°C under a nitrogen stream for 5 hours while distilling off the resulting water and ethylene glycol, followed by another hour under a reduced pressure of 5 to 20 mmHg. Next, 103 g (0.54 mol) of trimellitic anhydride was added, and the mixture was reacted for 1 hour under normal pressure, followed by another hour under a reduced pressure of 20 to 40 mmHg. The resin was extracted at the specified softening point. 219 g (3.5 mol) of ethylene glycol was recovered. The resulting resin was cooled to room temperature and then pulverized into particles. This was designated amorphous polyester resin A. The amorphous polyester resin A had a glass transition temperature Tg of 56° C., a softening point Tm of 135° C., an SP value of 11.0, an acid value of 37 mgKOH / g, and a hydroxyl value of 50 mgKOH / g.

[0085] <Production Example 2: Preparation of Crystalline Polyester Resin C> A 5-L reactor was charged with 132 g (1.12 mol) of 1,6-hexanediol, 230 g (1.0 mol) of 1,10-decanedicarboxylic acid, and 3 g of tetrabutoxy titanate as a polymerization catalyst. The reaction was carried out at 210°C under atmospheric pressure for 5 hours, while distilling off the water produced. The reaction was then continued under reduced pressure of 5 to 20 mmHg, and the resin was removed when the acid value reached 2 mg KOH / g or less. The resulting resin was cooled to room temperature and then pulverized into particles. This was designated crystalline polyester resin C. Crystalline polyester resin C had a melting point (Tmp) of 80°C, a softening point (Tm) of 88°C (Tm / Tmp = 1.1), and an SP value of 9.5.

[0086] <Production Example 3: Preparation of large particle size silica S1> Next, silica sol was prepared by the sol-gel method, and the obtained silica sol was subjected to a hydrophobic treatment with hexamethyldisilazane (HMDS) to obtain hydrophobic large particle silica S1 having an average primary particle diameter of 100 nm.

[0087] <Preparation of Toner in Example 1> <Material mixing, kneading, pulverization, and classification processes> The binder resins used were 80% by mass of amorphous polyester resin A (Production Example 1) and 8% by mass of crystalline polyester resin C (Production Example 2). The colorant used was 6% by mass of a colorant (CI Pigment Blue 15:35:3, manufactured by DIC Corporation). The release agent used was 5% by mass of a monoester wax (manufactured by NOF Corporation, product name: WEP-3). The charge control agent used was 1% by mass of a salicylic acid compound (manufactured by Orient Chemical Industry Co., Ltd., product name: Bontron E-84). These materials were premixed for 5 minutes using an air flow mixer (Henschel mixer, manufactured by Mitsui Mining Co., Ltd. (now Nippon Coke and Engineering Co., Ltd.), model: FM20C). Then, the materials were melt-kneaded using an open-roll continuous kneader (manufactured by Mitsui Mining Co., Ltd. (now Nippon Coke and Engineering Co., Ltd.), model: MOS320-1800) to obtain a molten mixture. The open roll conditions were: the heating roll supply side temperature of 130°C, the discharge side temperature of 100°C, and the cooling roll supply side temperature of 40°C, the discharge side temperature of 25°C. Both the heating roll and the cooling roll had a diameter of 320 mm and an effective length of 1550 mm, with a roll gap of 0.3 mm on both the supply and discharge sides. The heating roll rotation speed was 75 rpm, the cooling roll rotation speed was 65 rpm, and the toner raw material supply rate was 5.0 kg / h. The resulting molten mixture was cooled with a cooling belt and then coarsely pulverized using a speed mill with a φ2 mm screen. The resulting coarsely pulverized product was finely pulverized using a jet pulverizer (Nippon Pneumatic Mfg. Co., Ltd., Model: IDS-2) to obtain a finely pulverized product (fine pulverization step). The resulting finely pulverized product was then classified using an elbow jet classifier (Nitetsu Mining Co., Ltd., Model: EJ-LABO) to obtain toner base particles (classification step). The average primary particle diameter of the obtained toner base particles was 6.7 μm, and the amount of ultrafine powder was 5% by mass.

[0088] <External addition process> 100 parts by mass of the obtained toner base particles, 1.0 part by mass of the large particle size silica S1 obtained in Production Example 3 as the large particle size silica, and 1.0 part by mass of silica particles as the small particle size silica (manufactured by Nippon Aerosil Co., Ltd., product name: AEROSIL (registered trademark) R976, number average primary particle size 7 nm, dimethyldichlorosilane surface treatment) were charged into an air flow mixer (Henschel mixer, manufactured by Mitsui Mining Co., Ltd. (now Nippon Coke and Engineering Co., Ltd.), model: FM20C), and the tip speed of the stirring blade was set to 40 m / s, and the mixture was stirred for 4 minutes.

[0089] <Developer manufacturing process> The obtained externally added toner and the resin-coated carrier obtained in Production Example 6 were mixed so that the concentration of the externally added toner relative to the total amount of the two-component developer was 7% by mass, thereby obtaining a two-component developer (toner) with a toner concentration of 7%.

[0090] <Preparation of Toner Used in Example 15> Evaluation was performed under the same conditions as in Example 1, except that the toner external addition process was changed as follows: 100 parts by mass of the obtained toner base particles, 1.0 part by mass of the large particle size silica S1 obtained in Production Example 3 as the large particle size silica, and 1.0 part by mass of silica particles as the small particle size silica (manufactured by Nippon Aerosil Co., Ltd., product name: AEROSIL (registered trademark) R976, number average primary particle size 7 nm, dimethyldichlorosilane surface treatment) were charged into an air flow mixer (Henschel mixer, manufactured by Mitsui Mining Co., Ltd. (now Nippon Coke and Engineering Co., Ltd.), model: FM20C), and the tip speed of the stirring blade was set to 40 m / s, and the mixture was stirred for 4 minutes. Next, 0.2 parts by mass of zinc stearate microparticles (average primary particle diameter 0.7 μm, manufactured by NOF Corporation, product name: Nissan Electol (registered trademark) MZ-2) as aliphatic metal salt particles were added to the air flow mixer, and the tip speed of the stirring blade was set to 40 m / s and the mixture was stirred for 2 minutes to obtain an externally added toner.

[0091] <Image forming device> The electrophotographic photosensitive member and toner thus obtained were mounted and placed in a unit of a digital copying machine (manufactured by Sharp Corporation, model: BP70M65) that had been modified for testing.

[0092] <Comparison between Examples 1 to 15 of the present disclosure and Comparative Examples 1 to 6> Below, Examples 1 to 15 of the present disclosure will be compared with Comparative Examples 1 to 6 with reference to Tables 1 to 4. Table 1 shows the blade 301, the vane member 402 and other conditions of Examples 1 to 11 of the present disclosure.

[0093] Table 2 shows the creep value of the photoreceptor 200, the water surface contact angle of the photosensitive layer 202, the amount of abrasion of the photosensitive layer 202, the streak evaluation of the printed image in each example, and other defects in Examples 1 to 11 of the present disclosure. Table 3 shows the blade 301, the blade member 402, and other conditions in Examples 12 to 15 of the present disclosure and Comparative Examples 1 to 6. Table 4 shows the creep value of the photoreceptor 200, the water surface contact angle of the photosensitive layer 202, the amount of abrasion of the photosensitive layer 202, the streak evaluation of the printed image in each example, and other defects in Examples 1 to 15 of the present disclosure and Comparative Examples 1 to 6. Note that the area of ​​the blade member 402 is the same for all of Examples 1 to 15 and Comparative Examples 1 to 6, 1743.75 mm 2 It is as follows.

[0094] [Table 1]

[0095] [Table 2]

[0096] [Table 3]

[0097] [Table 4]

[0098] <Water surface contact angle of photosensitive layer> The surface contact angles of water of the photosensitive layer 202 shown in Tables 2 and 4 were measured by dropping pure water as a reagent onto the surface of the photosensitive layer 202 and using a contact angle meter before the durability evaluation test of the photosensitive body 200 described below.

[0099] <Evaluation of photoreceptor durability> For the photoreceptor 200 of each example and comparative example, a durability evaluation test of the photoreceptor 200 was conducted by printing a character test chart specified in the ISO 19752 standard on 300,000 sheets of recording paper using the image forming apparatus 100. The amount of abrasion (film loss) of the photoreceptor 202 per 100,000 rotations of the photoreceptor 200 was calculated from the difference between the film thickness of the photoreceptor 202 at the start of the durability evaluation test and the film thickness of the photoreceptor 202 after printing 300,000 images. The durability of the photoreceptor 200 was evaluated based on the amount of abrasion. If the amount of abrasion is less than 1 μm, it is acceptable for the image forming apparatus 100 to be advertised as having a long life. If the amount of abrasion is 1 μm or more but less than 1.5 μm, it is acceptable for a typical image forming apparatus 100. If the amount of abrasion is 1.5 μm or more but less than 2.00 μm, it is acceptable for an inexpensive image forming apparatus 100. If the amount of scraping is 2.00 μm or more, the life of the photosensitive member 200 will be too short, which will cause problems in terms of practical use of the image forming apparatus 100 .

[0100] <Evaluation of streaks in printed images> FIG. 10 shows examples of printed images that correspond to the four-level evaluation in the streak evaluation of the present disclosure, as described in Tables 2 and 4. The four images shown in FIG. 10 are images of 33% density halftone images output after 10,000 images were printed using the image forming apparatus 100 under various conditions. In FIG. 10, the direction of the short side of each image is the direction along the first rotation direction of the photoreceptor 200. Streak defects in printed images occur near the top or bottom side of each image as black streaks that are parallel to the direction of the short side of each image. The four images shown in FIG. 10 are evaluated, from left to right, as follows: "A" indicates an excellent print result with no streaks; "B" indicates a good print result with almost no streaks; "C" indicates a print result with slight streaks but acceptable quality; and "F" indicates a print result with clear streaks and unacceptable quality. In the image forming apparatuses 100 of Examples 1 to 15 and Comparative Examples 1 to 6, after printing 10,000 images, a halftone image with a density of 33% was output, and the results of evaluating which of the above four levels the output printed image fell into are shown in Tables 2 and 4.

[0101] Example 1 is an example corresponding to the configuration of Embodiment 1 of the present application shown in FIG. 2. In Example 1, as shown in Table 1, the blade angle θ2 = 8° and the blade position θ1 = 23°. The blade member 402 has one cavity 403, and the area of ​​the cavity 403 is 700 mm 2 and the void ratio of the blade member 402 is approximately 40%. The photoreceptor 200 of Example 1 includes an aluminum conductive support 201 and a photoreceptor layer 202 consisting of two layers: a charge generation layer made of a butyral resin layer containing oxotitanyl phthalocyanine as a charge generation material, and a polyarylate resin layer containing a stilbene compound as a charge transport material. The creep value of the photoreceptor 200 is 4.67%. As shown in Table 2, the amount of scraping in Example 1 is 1.58 μm, and the streak evaluation is "C." In Example 1, both the amount of scraping and the streak evaluation are evaluated as acceptable for practical use in the image forming apparatus 100.

[0102] <Example 2> Example 2 is an example corresponding to the configuration of Embodiment 2 of the present application shown in Figure 5. In Example 2, as shown in Table 1, the blade angle θ2 = 10° and the blade position θ1 = 20°. The number of cavities 403 that the blade member 402 has is nine, and the area of ​​each cavity 403 is 78 mm 2 and the void ratio of the blade member 402 is approximately 40%. The photoreceptor 200 of Example 2 is the same as that of Example 1, and the creep value of the photoreceptor 200 is 4.67%. As shown in Table 2, in Example 2, the amount of scraping is 1.63 μm and the streak evaluation is "B". Comparing Example 1 and Example 2, the streak evaluation has improved from "C" to "B". Therefore, even if the void ratio is the same, it can be seen that providing multiple cavities 403 in the blade member 402 makes it easier to suppress the occurrence of streaks in the printed image.

[0103] <Comparative Example 1> Comparative Example 1 is an example of the configuration of Embodiment 1 of the present application. In Comparative Example 1, as shown in Table 3, the blade angle θ2 = 11° and the blade position θ1 = 22°. As in Example 2, the number of cavities 403 that the blade member 402 has is nine, and the area of ​​each cavity 403 is 78 mm 2 and the void ratio of the blade member 402 is approximately 40%. In Comparative Example 1, unlike Examples 1 and 2, the creep value of the photosensitive element 200 is 4.37%. In Comparative Example 1, as shown in Table 4, the amount of abrasion is 2.33 μm and the streak evaluation is "C". Comparing Examples 1 and 2 with Comparative Example 1, the amount of abrasion of the photosensitive layer 202 is greater in Comparative Example 1 than in Examples 1 and 2, which have creep values ​​of 4.5% or more, and the lifespan of the photosensitive element 200 is shortened to the extent that it becomes a problem in practical use of the image forming apparatus 100.

[0104] <Comparative Example 2> In Comparative Example 2, as shown in Table 3, the blade angle θ2 was set to 3°, and the other conditions were the same as in Example 2. In Comparative Example 2, because the blade angle θ2 was too small, the tip of the blade 301 rose from the surface of the photoreceptor 200, causing the toner 500 to slip through the blade 301. As a result, in Comparative Example 2, the toner 500 was more likely to accumulate on the photoreceptor 200, making it difficult for the toner 500 to be replaced, resulting in streaks in the printed image, and as shown in Table 4, the streak evaluation was "F."

[0105] <Comparative Example 3> In Comparative Example 3, as shown in Table 3, the blade angle θ2 was set to 25°, and the other conditions were the same as in Example 2. In Comparative Example 3, because the blade angle θ2 was too large, the supply of toner 500 between the photoreceptor 200 and the blade 301 decreased, and the frictional force between the photoreceptor 200 and the blade 301 increased, causing the blade 301 to bend back and reverse in the first rotation direction, as shown in Table 4. As a result, the blade 301 was no longer able to remove the toner 500 from the photoreceptor 200, and image printing could not continue.

[0106] <Comparative Example 4> In Comparative Example 4, as shown in Table 3, the blade position θ1 was set to 35°, and the other conditions were the same as in Example 2. In Comparative Example 4, because the blade position θ1 was too large, the supply of toner 500 between the photoreceptor 200 and the blade 301 decreased, and the frictional force between the photoreceptor 200 and the blade 301 increased, causing the blade 301 to bend back and reverse in the first rotation direction, as shown in Table 4. As a result, the blade 301 was unable to remove the toner 500 from the photoreceptor 200, and image printing could not continue.

[0107] <Comparative Example 5> In Comparative Example 5, as shown in Table 3, the blade position θ1 was set to 3°, and the other conditions were the same as in Example 2. In Comparative Example 5, because the blade position θ1 was too small, it was difficult for the blade 301 to remove the toner 500 on the photoreceptor 200, and old toner 500 remained and was difficult to replace, which resulted in the occurrence of streaks in the printed image, and as shown in Table 4, the streak evaluation was "F".

[0108] <Comparative Example 6> Comparative Example 6 is configured without providing cavities 403 in the blade member 402. As shown in Table 3, in Comparative Example 6, the blade angle θ2 is 14° and the blade position θ1 is 18°. The number of cavities 403 in the blade member 402 is zero, and the void ratio of the blade member 402 is also 0%. As in Examples 1 and 2, the creep value of the photoreceptor 200 is 4.67%. As shown in Table 4, in Comparative Example 6, the amount of scraping is 1.54 μm and the streak evaluation is "F." Comparing Examples 1 and 2 with Comparative Example 2, when the creep value of the photoreceptor 200 is the same, Examples 1 and 2, in which the blade member 402 is provided with cavities 403, have better streak evaluations. This shows that providing cavities 403 in the blade member 402 suppresses the occurrence of streaks in printed images.

[0109] Example 3 Example 3 is an example corresponding to the configuration of Embodiment 2 of the present application. In Example 3, as shown in Table 1, the blade angle θ2=11° and the blade position θ1=16°. The number of cavities 403 that the blade member 402 has is nine, and the area of ​​each cavity 403 is 30 mm 2and the void ratio of the blade member 402 is approximately 15%. The photoreceptor 200 of Example 3 is the same as that of Example 2, and the creep value of the photoreceptor 200 is 4.67%. As shown in Table 2, in Example 3, the amount of scraping is 1.74 μm, and the streak evaluation is "C". In Example 3, the void ratio of the blade member 402 is reduced, so the amount of toner 500 returning to the gap between the photoreceptor 200 and the blade 301 is reduced compared to Example 2. As a result, the amount of streaks occurring in the printed image is greater than in Example 2, but the streak evaluation is better than in Comparative Example 2, and the image forming apparatus 100 is evaluated as having no practical problems.

[0110] Example 4 Example 4 is an example corresponding to the configuration of Embodiment 2 of the present application. In Example 4, as shown in Table 1, the blade angle θ2 = 18° and the blade position θ1 = 15°. The number of cavities 403 that the blade member 402 has is nine, and the area of ​​each cavity 403 is 145 mm 2 and the void ratio of the blade member 402 is approximately 75%. The photoreceptor 200 in Example 4 is the same as that in Example 2, and the creep value of the photoreceptor 200 is 4.67%. In Example 4, as shown in Table 2, the amount of scraping is 1.71 μm, and the streak evaluation is "C." In Example 4, the void ratio of the blade member 402 is increased, so the amount of toner 500 that returns between the photoreceptor 200 and the blade 301 is greater than in Example 2. As a result, the amount of remaining old toner 500 increases, and the amount of streaks that occur in the printed image is greater than in Example 2. However, compared to Comparative Example 2, the streak evaluation is better, and the image forming apparatus 100 is evaluated as having no practical problems.

[0111] <Example 5> Example 5 is an example corresponding to a modification of Embodiment 2 of the present application. In Example 5, as shown in Table 1, the blade angle θ2=6° and the blade position θ1=20°. The number of cavities 403 that the blade member 402 has is 45, and the area of ​​each cavity 403 is 16 mm 2The blade member 402 has a void ratio of approximately 41%. In Example 5, the blade member 402 has 45 cavities 403 arranged in a mesh pattern. The photoreceptor 200 in Example 5 is the same as that in Example 2, and the creep value of the photoreceptor 200 is 4.67%. As shown in Table 2, the scraping amount in Example 5 is 1.70 μm, and the streak evaluation is "A." Comparing Example 2 and Example 5, the streak evaluation is improved from "B" to "A." Therefore, in Example 5, the number of cavities 403 in the blade member 402 is increased compared to Example 2, so that the toner 500 is more agitated than in Example 5 when passing through the cavities 403. This makes the amount of toner 500 more uniform in the axial direction of the photoreceptor 200 between the photoreceptor 200 and the blade 301, further reducing the occurrence of streaks in the printed image.

[0112] Example 6 Example 6 is an example corresponding to a modified example of Embodiment 2 of the present application, as shown in Figure 7. In Example 6, as shown in Table 1, the blade angle θ2 = 12° and the blade position θ1 = 21°. The number of cavities 403 that the blade member 402 has is 180, and the area of ​​each cavities 403 is 4 mm 2 The blade member 402 has a void ratio of approximately 41%. In Example 6, the blade member 402 has 180 cavities 403 arranged in a mesh pattern. The photoreceptor 200 in Example 6 is the same as that in Example 2, and the creep value of the photoreceptor 200 is 4.67%. As shown in Table 2, in Example 6, the amount of scraping is 1.67 μm, and the streak evaluation is "A." Comparing Example 2 and Example 6, the streak evaluation is improved from "B" to "A." Therefore, in Example 6, the number of cavities 403 in the blade member 402 is increased compared to Example 2, so that the amount of toner 500 between the photoreceptor 200 and the blade 301 in the axial direction of the photoreceptor 200 is more uniform, and the occurrence of streaks in the printed image is further reduced.

[0113] Example 7 Example 7 is an example corresponding to the configuration of a modified example of Embodiment 2 of the present application shown in FIG. 7. In Example 7, as shown in Table 1, the blade angle θ2 = 13° and the blade position θ1 = 11°. The number of cavities 403 that the blade member 402 has is 720, and the area of ​​each cavity 403 is 1 mm 2 The blade member 402 has a void ratio of approximately 41%. In Example 7, the blade member 402 has 720 cavities 403 arranged in a mesh pattern. The photoreceptor 200 in Example 7 is the same as that in Example 2, and the creep value of the photoreceptor 200 is 4.67%. As shown in Table 2, the amount of scraping in Example 7 is 1.62 μm, and the streak evaluation is "C." Comparing Examples 5 and 6 with Example 7, the streak evaluation is worse. Therefore, in Example 7, the number of cavities 403 in the blade member 402 is increased even more than in Example 6, and the area per cavity 403 is reduced, causing clogging. As a result, the amount of toner 500 becomes uneven in the axial direction of the photoreceptor 200 between the photoreceptor 200 and the blade 301, increasing the number of streaks. In addition, when Example 7 is compared with Comparative Example 2, the streak evaluation is improved, and the image forming apparatus 100 is evaluated as having no practical problems.

[0114] Example 8 Example 8 is an example corresponding to the configuration of embodiment 3 of the present application, as shown in Figure 8. In Example 8, as shown in Table 1, the blade angle θ2 = 9° and the blade position θ1 = 17°. The number of cavities 403 that the blade member 402 has is nine, and the area of ​​each cavity 403 is 78 mm 2, and the void ratio of the blade member 402 is approximately 40%. Furthermore, of the nine cavities 403 provided in the blade member 402, 60% are located in the first region 407 and 40% are located in the second region 408. The photoconductor 200 in Example 8 is the same as that in Example 2, and the creep value of the photoconductor 200 is 4.67%. As shown in Table 2, in Example 8, the amount of scraping is 1.57 μm and the streak evaluation is "A." Comparing Example 2 and Example 8, the streak evaluation is improved from "B" to "A," and the amount of scraping is also reduced. In Example 8, the blade member 402 has an increased ability to scrape up the toner 500, making it easier to replace the toner 500, further suppressing the occurrence of streaks in printed images. Furthermore, the amount of toner 500 resupplied from the cavities 403 to the blade 301 is ensured, thereby extending the life of the photoconductor 200.

[0115] Example 9 Example 9 is an example corresponding to the configuration of Embodiment 4 of the present application, as shown in Figure 9. In Example 9, as shown in Table 1, the blade angle θ2 = 10° and the blade position θ1 = 20°. The number of cavities 403 that the blade member 402 has is nine, and the area of ​​each cavity 403 is 78 mm 2 and the void ratio of the blade member 402 is approximately 40%. Furthermore, the blade member 402 has a flexible brush portion 409. The photoreceptor 200 of Example 9 is the same as that of Example 2, and the creep value of the photoreceptor 200 is 4.67%. As shown in Table 2, the amount of scraping in Example 9 is 1.60 μm, and the streak evaluation is "A." Comparing Example 2 and Example 9, the streak evaluation is improved from "B" to "A." Therefore, in Example 9, the bending of the brush portion 409 causes the blade member 402 to largely repel the toner 500 on the blade 301, making it easier for the toner 500 to be replaced, further suppressing the occurrence of streaks in the printed image.

[0116] Example 10 In Example 10, the surface contact angle of water on the photosensitive layer 202 is 97.7°. In Examples 1 to 9 described above, the surface contact angle of water on the photosensitive layer 202 is 86.6°. In Example 10, as shown in Table 1, the blade angle θ2 is 7° and the blade position θ1 is 25°. The blade member 402 has nine cavities 403, and the area of ​​each cavity 403 is 78 mm 2 and the void ratio of the blade member 402 is approximately 40%. The photoreceptor 200 of Example 10 differs from Example 2 in that the resin material used in the charge transport layer included in the photosensitive layer 202 is a mixed material of polyarylate resin and polycarbonate resin, which increases the surface contact angle of water on the photosensitive layer 202. The creep value of the photoreceptor 200 with the photosensitive layer 202 is 4.57%. As shown in Table 2, in Example 10, the amount of scraping is 1.92 μm, and the streak evaluation is "A". Comparing Example 2 and Example 10, the streak evaluation has improved from "B" to "A". Therefore, in Example 10, the increased surface contact angle of water on the photosensitive layer 202 makes the surface of the photosensitive element 200 slippery, making it difficult for the toner 500 to adhere to the surface of the photosensitive element 200, and the toner 500 is easily removed by the blade 301, making it easier for the toner 500 to be replaced, further reducing the occurrence of streaks.

[0117] Example 11 In Example 11, the photosensitive layer 202 contains a polycarbonate resin having both the structural units represented by the above-mentioned chemical formula (1) and the following chemical formula (2). In Example 11, as shown in Table 1, the blade angle θ2 is 14° and the blade position θ1 is 7°. The number of cavities 403 in the blade member 402 is nine, and the area of ​​each cavity 403 is 78 mm. 2and the void ratio of the blade member 402 is approximately 40%. The photoreceptor 200 of Example 11 differs from Example 2 in that the resin material used in the charge transport layer included in the photosensitive layer 202 is a polycarbonate resin having both the structural units represented by the above-mentioned chemical formula (1) and the following chemical formula (2). The creep value of the photoreceptor 200 is 5.03%, and the surface contact angle of water on the photosensitive layer 202 is 92.1°. As shown in Table 2, the amount of abrasion in Example 11 is 1.48 μm, and the streak evaluation is "B". Comparing Example 2 and Example 11, the amount of abrasion is smaller in Example 11, and the wear resistance of the photosensitive layer 202 is improved, resulting in a longer lifespan of the photoreceptor 200.

[0118] Example 12 Example 12 is an example in which the photosensitive layer 202 contains fluorine-based resin particles. In Example 12, as shown in Table 3, the blade angle θ2 is 10° and the blade position θ1 is 19°. The blade member 402 has nine cavities 403, and the area of ​​each cavity 403 is 78 mm 2 and the void ratio of the blade member 402 is approximately 40%. The photoreceptor 200 of Example 12 differs from Example 2 in that particles of a tetrafluoroethylene resin material are added as fluorine-based resin particles to a polyarylate resin layer containing a stilbene compound, which is the charge transport material of the photosensitive layer 202. The creep value of the photoreceptor 200 is 4.51%, and the surface contact angle of water on the photosensitive layer 202 is 98.4°. As shown in Table 4, the amount of abrasion in Example 12 is 1.11 μm, and the streak evaluation is "A". Comparing Example 2 and Example 12, the amount of abrasion is smaller in Example 12, and the mechanical strength of the photosensitive layer 202 is improved, resulting in a longer lifespan of the photoreceptor 200.

[0119] Example 13 Example 13 is an example in which the photosensitive layer 202 contains inorganic particles. In Example 13, as shown in Table 3, the blade angle θ2 is 8° and the blade position θ1 is 22°. The number of cavities 403 that the blade member 402 has is nine, and the area of ​​each cavity 403 is 78 mm 2and the void ratio of the blade member 402 is approximately 40%. The photoreceptor 200 of Example 13 differs from Example 2 in that silicon dioxide particles are added as inorganic particles to a polyarylate resin layer containing a stilbene compound, which is the charge transport material of the photosensitive layer 202. The creep value of the photoreceptor 200 is 4.61%, and the surface contact angle of water on the photosensitive layer 202 is 91.0°. As shown in Table 4, the amount of abrasion in Example 13 is 0.83 μm, and the streak evaluation is "B". Comparing Example 2 and Example 13, the amount of abrasion is smaller in Example 13, and the mechanical strength of the photosensitive layer 202 is improved, resulting in a longer lifespan of the photoreceptor 200.

[0120] Example 14 Example 14 is an example of a configuration in which the photosensitive layer 202 contains a resin having a cross-linked structure. In Example 14, a compound having a structure represented by chemical formula (3) is used in the photosensitive layer 202, and a cross-linked structure is formed in the resin contained in the photosensitive layer 202 by performing an electron beam irradiation treatment and a heat treatment. In Example 14, as shown in Table 3, the blade angle θ2 = 16° and the blade position θ1 = 9°. The blade member 402 has nine cavities 403, and the area of ​​each cavity 403 is 78 mm 2 The photoreceptor 200 of Example 14 differs from Example 2 in that a compound having the structure shown in chemical formula (3) below is further incorporated into the polyarylate resin containing a stilbene compound, which is the charge transport material of the photosensitive layer 202. The resin is then irradiated with an electron beam before being cured, forming a crosslinked structure in the resin contained in the photosensitive layer 202. The creep value of the photoreceptor 200 is 4.79%, and the water surface contact angle of the photosensitive layer 202 is 84.1°. As shown in Table 4, the amount of abrasion in Example 14 is 0.94 μm, and the streak evaluation is "B." Comparing Example 2 and Example 14, the amount of abrasion is smaller in Example 14. The formation of a crosslinked structure in the resin improves the mechanical strength of the photosensitive layer 202, thereby extending the life of the photoreceptor 200.

[0121] Example 15 Example 15 is an example in which toner 500 contains fatty acid metal salt particles. Toner 500 of Example 15 contains zinc stearate particles as fatty acid metal salt particles. As shown in Table 3, Example 15 has a blade angle θ2 = 13° and a blade position θ1 = 14°. The number of cavities 403 in blade member 402 is nine, and the area of ​​each cavity 403 is 78 mm 2 and the void ratio of the blade member 402 is approximately 40%. The photoreceptor 200 of Example 15 is the same as that of Example 2, and the creep value of the photoreceptor 200 is 4.67%, and the surface contact angle of water on the photosensitive layer 202 is 86.6°. As shown in Table 4, in Example 15, the amount of scraping is 1.30 μm and the streak evaluation is "A". Comparing Example 2 and Example 15, the streak evaluation has improved from "B" to "A", and the amount of scraping has also decreased. Therefore, by including fatty acid metal particles in the toner 500, the life of the photoreceptor 200 is further extended and the occurrence of streaks in printed images is further suppressed.

[0122] The present disclosure is not limited to the configurations of the above-described embodiments and modified examples, and may be replaced with a configuration that is substantially the same as the configurations shown in the above-described embodiments and modified examples, a configuration that has the same effect, or a configuration that can achieve the same purpose. [Explanation of symbols]

[0123] 100: Image forming device 101:Main body 102: Paper tray 103: Charging device 104: Exposure equipment 105: Developing device 106: Transfer roller 107: Static eliminator 108: Fuser unit 109: Paper ejection roller 110: Paper output tray 200: Photoreceptor 201: Conductive support 202: Photosensitive layer 203: Highest point of photoreceptor 204: Rotation center of photosensitive drum 205: Contact point between photoconductor and blade 300: Cleaning department 301: Blade 302: Top of the blade 303: Conveyor screw 400: Paddle material 401: Paddle shaft 402: Blade member 403: Hollow 404: Side 1 405: Side 2 406: Center line 407:First area 408:Second area 409: Brush section 500: Toner

Claims

1. An image forming apparatus including a rotating photoreceptor having a photosensitive layer on a conductive support, and a cleaning member for removing toner adhering to the surface of the photoreceptor, The photoreceptor has a creep value of 4.5 or more when a maximum load of 30 mN is applied to the surface in an environment of a temperature of 25° C. and a relative humidity of 50%, the cleaning member includes a blade that scrapes off toner adhering to the surface of the photosensitive member, and a paddle member that scoops up the toner scraped off from the surface of the photosensitive member by the blade; the blade contacts the photosensitive member at a position inclined at an angle of 5° or more and less than 30° downstream of the highest point of the photosensitive member in the rotation direction of the photosensitive member, and the angle formed between the blade and the outer peripheral surface of the photosensitive member is 5° or more and less than 20°; The paddle member has a paddle shaft and a blade member, and a cavity is provided in the blade member. Image forming device.

2. The image forming apparatus according to claim 1 , wherein at least one of the blade members has a plurality of the cavities.

3. 3. The image forming apparatus according to claim 1, wherein in one of the blade members having the cavities, the ratio of the total area of ​​the cavities to the total area of ​​the blade member is 15% or more and 75% or less.

4. The area of ​​at least one of the cavities is 4 mm ２ Over 16mm ２ 4. The image forming apparatus according to claim 3, wherein:

5. The blade member has a first side fixed to the paddle shaft and a second side closer to the blade, 2. The image forming apparatus according to claim 1, wherein when the blade member is divided into a first region between the center line between the first side and the second side and the first side, and a second region between the center line and the second side, the proportion of the area occupied by the cavity in the first region is greater than the proportion of the area occupied by the cavity in the second region.

6. 2. The image forming apparatus according to claim 1, wherein the blade member has a flexible brush portion at a portion that contacts the photosensitive member.

7. The image forming apparatus according to claim 1 , wherein the paddle member has a plurality of the blade members.

8. 2. The image forming apparatus according to claim 1, wherein the photosensitive layer has a surface contact angle with water of 95 degrees or more.

9. 2. The image forming apparatus according to claim 1, wherein the photosensitive layer contains a polycarbonate resin having both of two structural units represented by the following chemical formula (1) and the following chemical formula (2). In the chemical formula, R １ , R ２ , R ３ , R ４ Each of the groups is either a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 6 carbon atoms.

10. The image forming apparatus according to claim 1 , wherein the photosensitive layer contains at least one of inorganic particles and fluorine-based resin particles.

11. The image forming apparatus according to claim 1 , wherein the photosensitive layer contains a resin having a crosslinked structure.

12. The image forming apparatus according to claim 1 , wherein the toner contains fatty acid metal salt particles.

Images