Roll shaft, developing roller and developing box

Abstract

The invention discloses a roller shaft, a developing roller and a developing cartridge, the roller shaft can be used for an image forming apparatus, and the roller shaft comprises a cylindrical shaft body extending in a first direction; the supported end is positioned at the end part of the shaft body in the first direction; the roll shaft is a plastic shaft and is prepared from GF and PBT / PET. The roller shaft in the scheme is a plastic shaft and is easy to process / form, so that the production cost of the developing box is reduced, and meanwhile, the preparation raw materials and the size of the roller shaft are correspondingly set to ensure the strength and the high temperature resistance of the roller shaft, so that the normal work of the developing roller is ensured.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus, and more particularly to a roller shaft, a developing roller and a developing cartridge. Background Art

[0002] A developing cartridge is a detachable part widely used in an image forming apparatus. A developing roller is provided on the developing cartridge. The developing roller contacts a photosensitive drum in the image forming apparatus to transfer a developer, so that the photosensitive drum is developed. The developing roller is formed by a roller shaft and a roller body, and the roller shaft drives the roller body to rotate. In the prior art, in order to ensure the strength of the roller shaft, the roller shaft is generally a steel shaft. However, the price of the steel shaft is generally relatively high, which is not conducive to controlling the production cost of the developing cartridge; and the surface of the steel shaft needs to be coated (such as nickel) so that the steel shaft can be better preserved, and the coating of the steel shaft is not environmentally friendly; furthermore, the steel shaft needs to be processed multiple times to form a qualified roller shaft, and the processing process is relatively complicated, increasing the forming difficulty of the roller shaft. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a roller shaft with a simple structure and appropriate strength.

[0004] According to one aspect of the present invention, there is provided a roller shaft that can be used in an image forming apparatus, the roller shaft comprising:

[0005] A shaft body extending in a first direction and being cylindrical;

[0006] A supported end located at an end of the shaft body in the first direction;

[0007] The roller shaft is a plastic shaft, and its preparation raw materials include GF.

[0008] In some embodiments, the preparation raw materials of the roller shaft further include PET or PBT.

[0009] In some embodiments, the weight percentage of the GF is 30% - 50%.

[0010] In some embodiments, the roller shaft is formed by injection molding.

[0011] In some embodiments, the size of the supported end in the radial direction is less than or equal to the size of the shaft body in the radial direction.

[0012] In some embodiments, the supported end has a chamfer at an end away from the shaft body in the first direction.

[0013] In some embodiments, the first size of the roller shaft in the radial direction is not less than 7 mm, and the first size is the size of the shaft body in the radial direction.

[0014] In some embodiments, the first dimensional range of the roller shaft in the radial direction is 7 mm to 19 mm.

[0015] According to another aspect of the present invention, there is provided a developing roller, which includes:

[0016] A roller body, extending in a first direction, being a hollow cylindrical shape, and capable of adsorbing the developer in the developing cartridge;

[0017] It further includes: the roller shaft as described in any one of the above;

[0018] The roller body surrounds the roller shaft, and the roller shaft can drive the roller body to rotate.

[0019] In some embodiments, the roller body has conductivity, and there is no electrical connection between the roller body and the roller shaft.

[0020] In some embodiments, the radial dimension of the developing roller is the sum of the first dimension of the roller shaft in the radial direction and the first thickness of the roller body in the radial direction. The radial dimension of the developing roller is 13 mm, the first dimension of the roller shaft in the radial direction is in the range of 7 mm to 12 mm, and the first thickness of the roller body in the radial direction is in the range of 1 mm to 6 mm.

[0021] According to another aspect of the present invention, there is provided another developing roller for an image forming apparatus, which includes:

[0022] A roller shaft, which is a plastic shaft extending in a first direction. The roller shaft includes a shaft body and a supported end. In the first direction, the supported end is located at the end of the shaft body. In the radial direction perpendicular to the first direction, the roller shaft has a first dimension;

[0023] A roller body, surrounding the shaft body and rotating following the shaft body. In the radial direction, the roller body has a first thickness. In the radial direction, the dimension of the developing roller is the sum of the first dimension and the first thickness,

[0024] The first thickness is 1 mm to 8 mm.

[0025] In some embodiments, the dimension of the developing roller is 13 mm, the first dimension is 7 mm to 12 mm, and the first thickness is 1 mm to 6 mm.

[0026] In some embodiments, the dimension of the developing roller is 16 mm, the first dimension is 8 mm to 15 mm, and the first thickness is 1 mm to 8 mm.

[0027] In some embodiments, the dimension of the developing roller is 20 mm, the first dimension is 12 mm to 19 mm, and the first thickness is 1 mm to 8 mm.

[0028] According to a third aspect of the present invention, there is provided a developing cartridge including the developing roller as described in any one of the above, and the developing roller is rotatable.

[0029] Advantages of the present invention: In this solution, the roller shaft is a plastic shaft, which is easy to process / form, thereby reducing the production cost of the developing cartridge. At the same time, the preparation raw materials and dimensions of the roller shaft are correspondingly set to ensure the strength and high-temperature resistance of the roller shaft, so as to ensure the normal operation of the developing roller. Description of the Drawings

[0030] Figure 1 is a schematic structural view of a developing cartridge in some embodiments of the present invention;

[0031] Figure 2 is an exploded schematic view of a developing cartridge in some embodiments of the present invention;

[0032] Figure 3 is an exploded view of the first end of a developing cartridge in some embodiments of the present invention;

[0033] Figure 4 is a schematic structural view of a roller body and a roller shaft in some embodiments of the present invention;

[0034] Figure 5 is a side view of a roller body and a roller shaft in some embodiments of the present invention;

[0035] Figure 6 is a cross-sectional view of a developing roller in some embodiments of the present invention. Detailed Description of the Embodiments

[0036] The present invention will be further described in detail below with reference to the drawings. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without making creative efforts based on the embodiments of the present invention fall within the scope of protection of the present invention.

[0037] It should be noted that the terms "first", "second", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first", "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0038] In the present invention, unless otherwise clearly specified or limited, terms such as "installed", "connected", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] In the present invention, unless otherwise clearly specified or limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0040] In the above description, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0041] In the following description of directions, in one embodiment, the left - right direction in the drawings is taken as the first direction, the front - back direction is taken as the second direction, and the up - down direction is taken as the third direction, and the first direction, the second direction, and the third direction are perpendicular to each other.

[0042] As Figures 1-6 shown, this embodiment provides a roller shaft, which can be used in the developing cartridge 1. The developing cartridge 1 is detachably installed in the image forming apparatus. Specifically, the developing cartridge 1 is installed on a drum cartridge including a photosensitive drum to form a processing cartridge, and then they are jointly installed in the image forming apparatus. The developing cartridge 1 includes a cartridge body 10, a developing assembly, a transmission assembly, a pressing assembly, and an identification assembly.

[0043] As Figures 1-2As shown, the developer is stored in the cartridge 10. The cartridge 10 has a first end 11 and a second end 12 oppositely arranged in the first direction, a third end 13 and a fourth end 14 oppositely arranged in the second direction, and a fifth end and a sixth end oppositely arranged in the third direction. The drive assembly is located at the first end 11 and is configured to receive the power output by the image forming apparatus and transmit the power to the components in the developing assembly. The first cover 31 is detachably fixed to the first end 11 by means such as screws and snap-fits. The first cover 31 at least covers a part of the drive assembly and can protect the drive assembly.

[0044] The developing assembly includes a developing roller 131 and a powder feeding roller (not shown). The developing roller 131 and the powder feeding roller are rotatably supported by the first end 11 and the second end 12. The developing roller 131 and the powder feeding roller extend in the first direction and their rotation axes also extend in the first direction. The powder feeding roller is disposed adjacent to the developing roller 131 and transmits the developer to the developing roller 131. The developing roller 131 transmits the developer to the photosensitive drum of the drum cartridge. The developing assembly further includes a blade 132 which contacts the developing roller 131 to control the thickness of the developer layer on the developing roller 131.

[0045] As Figure 3 shown, the drive assembly is disposed at the first end 11. The drive assembly includes a driving part rotatably mounted on the first end 11. The rotation axis of the driving part extends in the first direction. The driving part includes a driving gear 402 and a power receiving part 401 which are integrally formed coaxially. The driving gear 402 is closer to the side wall of the first end 11 than the power receiving part 401 in the first direction. The power receiving part 401 is configured to be coupled to the power output shaft of the image forming apparatus to receive the power output by the image forming apparatus.

[0046] The drive assembly further includes a developing gear 41 and a powder feeding gear 42. The developing gear 41 and the powder feeding gear 42 are both meshed with the driving gear 402 to receive power and rotate. The developing gear 41 is located at the first end 11 and drives the developing roller 131 to rotate. The powder feeding gear 42 is located at the first end 11 and drives the powder feeding roller to rotate. In some embodiments, a stirring frame and a stirring gear may be provided to stir the developer in the cartridge 10. The number of gears and the meshing relationship of the drive assembly in this embodiment are not limited and can be set according to actual needs.

[0047] As Figures 4-5As shown, the developing roller 131 includes a roller body 1311 and a roller shaft 1312. The roller body 1311 surrounds a part of the roller shaft 1312, and the roller shaft 1312 drives the roller body 1311 to rotate. The roller body 1311 is used to adsorb the developer. In the existing process, the roller body 1311 can be combined with the roller shaft 1312 through an injection molding process or a pipe threading process, etc. In a process of combining the roller body 1311 and the roller shaft 1312, the roller body 1311 is made of liquid silicone material. In a high-temperature environment, the liquid silicone and the roller shaft 1312 are placed in a predetermined mold. The roller body 1311 surrounds the surface of the roller shaft 1312 in a liquid state. After a period of high-temperature treatment, the roller body 1311 solidifies from a liquid to a solid and tightly combines with the roller shaft 1312, that is, the roller body 1311 is solidified into a solid and covers the surface of the roller shaft 1312 by means of high temperature. In another combination process, the roller body 1311 is made of rubber material. First, the roller body 1311 is injection molded into a hollow cylindrical solid state, and then the roller shaft 1312 is inserted into the hollow of the roller body 1311 by an insertion method (i.e., the pipe threading process). An adhesive (such as glue) can also be added between the roller body 1311 and the roller shaft 1312, and the adhesive combines with the roller body 1311 and the roller shaft 1312 in a high-temperature environment. After the roller body 1311 and the roller shaft 1312 are combined and formed, they will be placed in a high-temperature environment (vulcanizing furnace process environment) again to further process the developing roller 131. Generally, a high-temperature environment above 160 °C is used in the process, and in some processes, a high-temperature environment above 180 °C or 200 °C is even used to ensure that the roller body 1311 can solidify to a certain extent or meet the combination requirements of the roller body 1311 and the roller shaft 1312, so as to ensure that the roller body 1311 can stably adsorb the developer and contact the photosensitive drum to transfer the developer. The roller body 1311 has conductivity and can receive an external voltage. For example, the roller body 1311 is made of conductive rubber, or other conductive materials are added to the preparation raw materials of the roller body 1311, etc.

[0048] After the roller body 1311 and the roller shaft 1312 are combined, in order to correct the size or defects of the roller body 1311, the developing roller 131 will be further processed. During the processing, a certain abutment will be made on the roller shaft 1312. Therefore, in order to ensure that the roller shaft 1312 can be deformed or damaged neither in a high-temperature environment nor during reprocessing, the roller shaft 1312 needs to have excellent high-temperature resistance, wear resistance, and mechanical strength. The mechanical strength is generally mainly reflected in the bending stress and tensile stress (about 100 MPa and above), preferably 120 MPa - 180 MPa, which places certain requirements on the material of the roller shaft 1312.

[0049] In this embodiment, the roller shaft 1312 is preferably a plastic shaft made of a resin material combination. There is no electrical connection between the roller shaft 1312 and the roller body 1311, that is, they do not conduct electricity with each other. The roller body 1311 receives an external voltage but does not transfer the voltage to the roller shaft 1312. The advantage of the roller shaft 1312 being a plastic shaft is that there is no need to coat a metal film (such as a nickel film) on the surface of the plastic shaft. Even in a humid environment, the plastic shaft can still be well preserved, which not only simplifies the process of the roller shaft 1312 but also is beneficial to environmental protection. Moreover, since an adhesive is added between the roller shaft 1312 and the roller body 1311 to further stably combine the two, but after the adhesive reacts chemically with the roller body 1311, it will corrode the steel shaft or the metal film (such as a nickel film) on the surface of the steel shaft, which will in turn cause problems with the quality of the developing roller 131 and may pose a risk of poor printing. However, the plastic shaft has no risk of being corroded by the adhesive. Therefore, the plastic shaft has a more stable printing quality. Therefore, on the basis of meeting the requirements of high temperature resistance and wear resistance, the plastic shaft has greater advantages than the steel shaft in terms of cost, processing technology, and quality stability.

[0050] Therefore, in order to enable the plastic shaft to have good high temperature resistance and wear resistance, it is preferred that the roller shaft 1312 is made of a composite material.

[0051] In one embodiment, the composite material includes PBT (polybutylene terephthalate) and GF (Glass Fiber). The two are mixed in a certain proportion and injection molded to form the roller shaft 1312. PBT has good high temperature resistance and is an important thermoplastic polyester. GF is a commonly used reinforcing material in composite materials and has the advantages of high heat resistance, good corrosion resistance, and high mechanical strength. Among them, the weight percentage of GF is 20% - 50%. In this embodiment, 30% GF (the weight percentage of GF is 30%) is preferably used, or 50% GF (the weight percentage of GF is 50%) can also be used.

[0052] In another embodiment, the raw material for preparing the roller shaft 1312 can be PET (polyethylene terephthalate) + GF, where the weight percentage of GF is also 20% - 50%, preferably 30% GF or 50% GF. PET is also a thermoplastic polyester with excellent physical and mechanical properties and high temperature adaptability, and has excellent electrical insulation properties; alternatively, the roller shaft 1312 can also be made of other raw materials such as a glass shaft or other roller shafts as long as they have good high temperature resistance and wear resistance.

[0053] In this embodiment, the forming method of the roller shaft 1312 is injection molding. The raw materials to be prepared are placed in a fixed mold and can be formed after certain process treatments. Compared with the forming process of the steel shaft in the prior art, the forming method of the plastic shaft in this embodiment is more convenient and does not require multiple grinding processes, greatly reducing the manufacturing difficulty and cost of the roller shaft 1312. Moreover, general plastic products tend to embrittle or deform after being penetrated by water vapor in a humid environment. However, due to the extremely low water absorption of PET and PBT, they can maintain their physical properties in a humid environment. Therefore, the roller shaft 1312 made of PBT+GF or PET+GF will not have this defect. In addition to including PET (or PBT) and GF, other auxiliary materials (such as plasticizers) can also be added during the forming process of the roller shaft 1312.

[0054] In one embodiment, in order to enable the roller shaft 1312 and the roller body 1311 to have electrical connection, conductive materials (such as carbon black) can be added to the roller shaft 1312 or a conductive film can be plated on the outer surface of the roller shaft 1312.

[0055] Furthermore, anti-slip structures such as anti-slip patterns or anti-slip grooves can be added to the surface of the roller shaft 1312 to increase the friction between the roller shaft 1312 and the roller body 1311 and further enable the stable combination of the two.

[0056] Such as Figures 4-6As shown, the roller shaft 1312 extends in the first direction and is generally cylindrical as a whole (the length LD of the roller shaft 1312 on the market is about 240 mm to 260 mm, preferably 250 mm). The roller shaft 1312 includes a shaft body 13120, a first supported end 13121, and a second supported end 13122, preferably integrally formed. The shaft body 13120 is cylindrical. In the first direction, the first supported end 13121 and the second supported end 13122 are located at both ends of the shaft body 13120. Preferably, the dimensions of the first supported end 13121 and the second supported end 13122 in the radial direction are smaller than the dimensions of the shaft body 13120 in the radial direction. The first supported end 13121 is rotatably located at the first end 11, and the first supported end 13121 is supported by the side wall of the first end 11 or a component located at the first end 11. The first supported end 13121 has a D-shaped opening, and the D-shaped opening engages with the developing gear 41 so that the developing gear 41 drives the roller shaft 1312 to rotate. The second supported end 13122 is located at the second end 12 and is rotatably supported by the side wall of the second end 12 or a component located at the second end 12. In the first direction, the length LB of the roller body 1311 is not greater than the length of the shaft body 13120. Preferably, the lengths of the two are the same, that is, in the radial direction, the roller body 1311 completely covers the shaft body 13120. The length LB of the roller body 1311 is preferably 230 mm, and the lengths of the first supported end 13121 and the second supported end 13122 in the first direction are about 10 mm.

[0057] The sizes of the developing rollers 131 on the market are generally of the 13mm type, 16mm type or 20mm type. That is, in the radial direction perpendicular to the first direction, the overall size (radial size) of the developing roller 131 is 13mm, 16mm or 20mm, and the overall size is composed of the first thickness L0 of the roller body 1311 in the radial direction and the first size D1 of the roller shaft 1312 in the radial direction. Taking the 13mm type developing roller 131 as an example, in this embodiment, in order to ensure that the roller shaft 1312 has sufficient strength, the first size D1 of the shaft body 13120 in the radial direction is at least 7mm, and the range of the first size D1 is 7mm to 19mm. And in order to ensure that the roller body 1311 can stably contact the photosensitive drum to transfer the developer, the unilateral thickness L1 in the radial direction is at least 0.5mm. Therefore, the first size D1 of the roller shaft 1312 (shaft body 13120) in the radial direction is not less than 7mm, and the specific range of the first size D1 is 7mm to 12mm. In this embodiment, it is preferably 8mm. The range of the unilateral thickness L1 of the roller body 1311 in the radial direction is 0.5mm to 3mm. In this embodiment, the unilateral thickness L1 is preferably 2.5mm. And the overall thickness of the roller body 1311 after removing the hollow part in the radial direction is the first thickness L0, and the first thickness L0 is twice the unilateral thickness L1, that is, the range of the first thickness L0 is 1mm to 6mm. In this embodiment, it is preferably 5mm. In another embodiment, the first size D1 is 10mm and the first thickness L0 is 3mm.

[0058] If the 16mm type developing roller is taken as an example, the range of the first size D1 of the roller shaft 1312 (shaft body 13120) in the radial direction is 8mm to 15mm, and the range of the unilateral thickness L1 of the roller body 1311 in the radial direction is 0.5mm to 4mm, that is, the first thickness L0 is 1mm to 8mm.

[0059] If the 20mm type developing roller is taken as an example, the range of the first size D1 of the roller shaft 1312 (shaft body 13120) in the radial direction is 12mm to 19mm, and the range of the unilateral thickness L1 of the roller body 1311 in the radial direction is 0.5mm to 4mm, that is, the first thickness L0 is 1mm to 8mm.

[0060] The maximum size D0 of the developing roller 131 in the radial direction is the sum of the first size D1 of the roller shaft 131 and the first thickness L0 of the roller body 1311.

[0061] To sum up, the first thickness L0 = the maximum size D0 - the first size D1, and 1mm ≤ the first thickness L0 ≤ 8mm.

[0062] If starting from the cost of the developing roller 131, comparing the material costs of the roller body 1311 and the roller shaft 1312, taking the maximum value of the first dimension D1 is more conducive to cost control; if the best contact between the developing roller 131 and the photosensitive drum is required, comparing the characteristics of the roller body 1311 and the roller shaft 1312, taking the maximum value of the first thickness L0 is more appropriate. That is, the size of the roller shaft 1312 (shaft body 13120) and the thickness of the roller body 1311 can be set according to the actual required model of the developing roller 131.

[0063] In this embodiment, the dimensions of the first supported end 13121 and the second supported end 13122 in the radial direction are smaller than the dimensions of the shaft body 13120 in the radial direction. Preferably, the dimensions of the first supported end 13121 and the second supported end 13122 in the radial direction are the same, both being the second dimension D2, and they can also be different in some embodiments. The range of the second dimension D2 is 4 mm to 7 mm. By making the second dimension D2 smaller than the first dimension D1, the developing roller 131 can be more easily rotatably supported by the cassette 10.

[0064] After the roller body 1311 and the roller shaft 1312 are combined, if the developing roller 131 needs to be processed again (such as the grinding process of the grinding machine) to correct the size or defects of the roller body 1311, tools will abut or clamp the first supported end 13121 and the second supported end 13122 so that the developing roller 131 can be stably fixed. Therefore, chamfers X are provided at the ends of the first supported end 13121 and the second supported end 13122 in the first direction (the ends away from the shaft body 13120). The tool abuts on the chamfer X or clamps the chamfer X in the first direction to achieve the fixing effect of the developing roller 131. In order to increase the fixing effect of the tool on the developing roller 131, usually the contact area between the tool and the first supported end 13121 and the second supported end 13122 (that is, the contact area between the tool and the chamfer X) is increased. Therefore, the sizes of the first supported end 13121 and the second supported end 13122 are made as large as possible, and the size of the second dimension D2 is made as close as possible to the size of the first dimension D1, thereby making the size of the chamfer X larger. On the other hand, in the grinding process of the grinding machine, if the strength of the roller shaft 1312 is insufficient, the roller shaft 1312 will be deformed and unusable.

[0065] If the radial dimensions of the first supported end 13121 and the second supported end 13122 are made smaller than the radial dimension of the shaft body 13120, additional machining procedures for the first supported end 13121 and the second supported end 13122 respectively will be added in the manufacturing process of the roller shaft 1312, and this procedure will increase the production cost of the roller shaft 1312. Therefore, in another embodiment, to save the manufacturing cost of the roller shaft 1312, at least one of the first supported end 13121 and the second supported end 13122 is set to have the same radial dimension as the shaft body 13120 in the radial direction. That is, the range of the second dimension D2 is 4 mm to the first dimension D1. In this embodiment, preferably, the roller shaft 1312 is made by injection molding, and this step can be omitted. When the roller shaft 1312 is molded, the dimensions of the first supported end 13121 and the second supported end 13122 become smaller than the dimension of the shaft body 13120, simplifying the manufacturing method of the roller shaft 1312.

[0066] The following are the material selection and experimental conclusions of the roller shaft 1312 this time:

[0067]

[0068]

[0069] Table 1

[0070] As shown in Table 1, the material of the roller shaft 1312 is preferably PBT / PET and 30% - 50% GF. The molded roller shaft 1312 has good high-temperature resistance and mechanical strength. Roller shafts made of other materials all have defects in high-temperature resistance, mechanical strength, etc., and aluminum shafts and steel shafts in the prior art are not conducive to cost control.

[0071] It can be known that the roller shaft of the powder feeding roller can also use the roller shaft of the above-mentioned material. Due to the difference in the properties between the powder feeding roller and the developing roller 131, the surface of the roller shaft of the powder feeding roller is covered with sponge, and the overall thickness of the sponge is the overall size of the powder feeding roller minus the size of the powder feeding roller shaft. The overall thickness range of the sponge is 4 mm to 8 mm.

[0072] It can be known that the roller shaft of the charging roller (contacting the photosensitive drum and charging the photosensitive drum) on the drum cartridge can also use the roller shaft of the above-mentioned material. The roller shaft of the charging roller is covered with sponge or rubber, and the overall thickness of the sponge or rubber is the overall size of the charging roller minus the size of the charging roller shaft. The thickness of the sponge or rubber is 1 mm to 6 mm.

[0073] As Figure 1 and Figure 2As shown, the developing cartridge 1 further includes an electrode 121 for receiving an external voltage. The electrode 121 is electrically connected to at least one of the developing roller 131 and the powder feeding roller to transfer the voltage. In this embodiment, the electrode 121 is made of conductive resin, and the electrode 121 rotatably supports at least one of the developing roller 131 and the powder feeding roller. In some embodiments, it may also be that other components support the developing roller 131 and the powder feeding roller. The electrode can be firmly combined with the cartridge body 10 by snaps and screws, or it can first be snapped onto the cartridge body 10 and then further firmly combined with the cartridge body 10 by being pressed by another pressing plate. In this embodiment, the electrode 121 is not surrounded by the insulating material on the cartridge body 10. Preferably, the snaps are completely provided on the electrode 121, and only the snap positions are provided on the cartridge body 10. The electrode 121 includes an electricity receiving portion 1211, a first electricity transfer portion 1212, and a second electricity transfer portion (not shown). The electricity receiving portion 1211 is the end face of the electrode 121 in the first direction. The electricity receiving portion 1211 contacts the power supply terminal in the image forming apparatus to receive the voltage. The electricity receiving portion 1211 preferably has a flat end face. The first electricity transfer portion 1212 contacts the left end of the doctor blade 132 in the first direction to transfer the voltage. The doctor blade 132 contacts the roller main body 1311 to limit the thickness of the developer layer on the roller main body 1311 while transferring the voltage to the roller main body 1311. That is, the doctor blade 132 can be regarded as an intermediate conductive member. In some embodiments, an intermediate conductive member can be separately provided to contact the electrode 121 and the roller main body 1311, or the electrode 121 can directly contact the roller main body 121.

[0074] As Figures 1 to 3 shown, the identification component is located at the first end 11. The identification component includes a bracket 32 and a storage medium 33. A first installation groove 321 is provided at the upper end of the bracket 32. The storage medium 33 is installed in the first installation groove 321 by snap connection. In some embodiments, the storage medium 33 can also be installed on the bracket 32 by gluing or other means. The storage medium 33 stores information about the developing cartridge 1. The storage medium 33 includes an electrical contact surface 331 electrically connected thereto. When the developing cartridge 1 is installed in the image forming apparatus, the electrical contact surface 331 contacts the printer so that the storage medium 33 transfers the information to the image forming apparatus, thereby enabling the image forming apparatus to identify the developing cartridge 1.

[0075] As Figure 3 shown, a second installation groove 311 is provided on the first cover 31. The second installation groove 311 is provided near the rear end of the first cover 31. The bracket 32 is fixedly combined with the second installation groove 311 by snap connection. In this embodiment, it is preferred that the bracket 32 and the storage medium 33 cannot move relative to the cartridge body 10. In some embodiments, the storage medium 33 or the electrical contact surface 331 can move relative to the cartridge body 10 in the third direction.

[0076] As Figure 2 andFigure 3 As shown, a support member 34 and a lifting member 35 are provided at the first end 11. The lifting member 35 is used to cause the entire developing cartridge 1 to move. In this embodiment, it is preferred that the lifting member 35 is an elastic member, and more preferably a double-curved torsion spring to have a more stable elastic force. In the third direction, the lifting member 35 is located below the bracket 32. The support member 34 is joined to the first cover 31 by screws, and the support member 34 supports the lifting member 35.

[0077] During the process of installing the developing cartridge 1 on the drum cartridge 2 and installing it in the image forming apparatus, the lower end of the lifting member 35 contacts and deforms to avoid the interference member in the image forming apparatus. After the lifting member 35 passes over the interference member, it elastically recovers and causes the developing cartridge 1 to move relative to the image forming apparatus, thereby ensuring that the developing cartridge 1 is successfully installed in the image forming apparatus while the electrical contact surface 331 can be maintained at a certain height and contact the image forming apparatus.

[0078] In this embodiment, the roller shaft 1312 of the developing roller 131 is a plastic shaft, thereby reducing the production cost of the developing cartridge. At the same time, the material and dimensions of the roller shaft 1312 are set accordingly to ensure the strength and high temperature resistance of the roller shaft 1312, so as to ensure that the developing roller 131 can work normally. In this embodiment, the corresponding dimensions of the developing roller 131 are all optimal solutions and can be changed according to actual needs.

[0079] The above are only some embodiments of the present invention. For those of ordinary skill in the art, without departing from the inventive concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A roller shaft, which can be used in an image forming apparatus, and the roller shaft includes: A shaft body, extending in a first direction and having a cylindrical shape; A supported end, located at an end of the shaft body in the first direction; Characterized in that the roller shaft is a plastic shaft, and its preparation raw materials include GF.

2. A roller according to claim 1, characterized in that, The preparation raw materials of the roller shaft further include PET or PBT.

3. A roller according to claim 2, wherein, The weight percentage of the GF is 30% - 50%.

4. A roller according to claim 2, characterized in that, The roller shaft is formed by injection molding.

5. A roller shaft according to claim 2, characterized in that, The size of the supported end in the radial direction is less than or equal to the size of the shaft body in the radial direction.

6. A roller according to claim 5, characterized in that, The supported end has a chamfer at an end away from the shaft body in the first direction.

7. A roller according to claim 2, characterized in that, The first size of the roller shaft in the radial direction is not less than 7 mm, and the first size is the size of the shaft body in the radial direction.

8. A roller according to claim 7, characterized in that The first size range of the roller shaft in the radial direction is 7 mm - 19 mm.

9. A developing roller, and the developing roller includes: A roller body, extending in a first direction and having a hollow cylindrical shape, capable of adsorbing a developer in a developing cartridge; Characterized in that it further includes: the roller shaft according to any one of claims 1 - 8; The roller body surrounds the roller shaft, and the roller shaft can drive the roller body to rotate.

10. A developing roller according to claim 9, characterized in that, The roller body has conductivity, and there is no electrical connection between the roller body and the roller shaft.

11. A developing roller according to claim 9, wherein, The radial size of the developing roller is the sum of the first size of the roller shaft in the radial direction and the first thickness of the roller body in the radial direction. The radial size of the developing roller is 13 mm, the first size range of the roller shaft in the radial direction is 7 mm - 12 mm, and the first thickness range of the roller body in the radial direction is 1 mm - 6 mm.

12. A developing roller, used in an image forming apparatus, and the developing roller includes: A roller shaft, which is a plastic shaft extending in a first direction. The roller shaft includes a shaft body and a supported end. In the first direction, the supported end is located at an end of the shaft body. In the radial direction perpendicular to the first direction, the roller shaft has a first size; A roller body, surrounding the shaft body and rotating following the shaft body. In the radial direction, the roller body has a first thickness. In the radial direction, the size of the developing roller is the sum of the first size and the first thickness, Characterized in that the first thickness is 1 mm - 8 mm.

13. A developing roller according to claim 12, characterized in that, The size of the developing roller is 13 mm, the first size is 7 mm - 12 mm, and the first thickness is 1 mm - 6 mm.

14. A developing roller according to claim 12, characterized in that, The size of the developing roller is 16 mm, the first size is 8 mm - 15 mm, and the first thickness is 1 mm - 8 mm.

15. A developing roller according to claim 12, characterized in that, The size of the developing roller is 20 mm, the first size is 12 mm - 19 mm, and the first thickness is 1 mm - 8 mm.

16. A developing cartridge, characterized in that, Including the developing roller according to any one of claims 9 - 15, and the developing roller is rotatable.

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