Developing roller and cartridge

Abstract

The utility model discloses a developing roller and a box. Wherein the developing roller comprises a roller shaft, an insulating elastic body is arranged on the peripheral surface of the roller shaft, and the roller shaft is arranged to extend out from two axial end parts of the insulating elastic body; and a conductive coating is arranged on the peripheral surface of the insulating elastomer. The cartridge is used for being detachably mounted on the electrophotographic image forming equipment and comprises the developing roller. The developing roller disclosed by the utility model has the advantage of low manufacturing cost.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of electrophotographic imaging equipment, more particularly to a cartridge for installation in an electrophotographic imaging equipment and a developing roller for use in the cartridge. BACKGROUND

[0002] In an electrophotographic imaging equipment such as a laser printer or a copier, there is usually a cartridge installed in a detachable manner, which can be a developing cartridge or a process cartridge. The developing cartridge includes a developing roller, and the process cartridge further integrates a photosensitive drum on the basis of the developing cartridge. During the imaging process, the developer carried by the developing roller can be transferred to the photosensitive drum to develop the latent image on the photosensitive drum.

[0003] In the prior art, the developing roller includes a roller shaft and an electrically conductive elastomer constituting a developer carrying portion. Such an electrically conductive elastomer usually includes an electrically conductive filler such as carbon black and a base material such as rubber. Not only is the cost of the elastomer material itself high, but the manufacturing process is also complex and costly, for example, the electrically conductive filler needs to be particularly controlled to be uniformly distributed in the base material to meet the requirement for uniformity of the electrically conductive elastomer. SUMMARY

[0004] The main purpose of the utility model is to provide a developing roller which is beneficial to reduce the manufacturing cost and a cartridge having the developing roller.

[0005] To achieve the above main purpose, the utility model discloses a developing roller in the first aspect, including the roller shaft, the outer circumferential surface of the roller shaft is equipped with the insulating elastomer, the roller shaft is provided from the two axial end portions of the insulating elastomer, the outer circumferential surface of the insulating elastomer is equipped with the electrically conductive coating.

[0006] Further, the thickness of the electrically conductive coating can be 10 μm to 100 μm, preferably 20 μm to 50 μm.

[0007] Further, the surface resistance of the electrically conductive coating can be 10 5 Ω to 10 7 Ω.

[0008] Further, the Shore A hardness of the insulating elastomer can be 58-70 degrees.

[0009] Further, the entire outer circumferential surface of the insulating elastomer can be provided with the electrically conductive coating; or at least one end region of the outer circumferential surface of the insulating elastomer can have a bare surface not covered by the electrically conductive coating.

[0010] Further, the electrically conductive coating can be directly provided on the outer circumferential surface of the insulating elastomer.

[0011] Further, the roller shaft can be a conductive shaft or a non-conductive shaft.

[0012] Further, the outer diameter of the insulating elastic body is 8mm-25mm, and the length is 225mm-255mm; the diameter of the roller shaft is 5mm-8mm, and the length is 255mm-285mm.

[0013] To achieve the above-mentioned main purpose, the second aspect of the utility model discloses a box for being detachably installed to electrophotographic imaging equipment;Wherein, the box includes any one of the developing roller as described above.

[0014] Further, the box further includes:

[0015] The powder outlet knife has a blade that forms elastic electrical contact with the conductive coating;

[0016] The developing electrode is electrically connected with the powder outlet knife and can supply power to the conductive coating through the powder outlet knife.

[0017] The utility model has the following beneficial effects:

[0018] In the utility model, the elastic body of the developing roller is made of insulating material, which is conducive to reducing material cost;The surface of the insulating elastic body is provided with a conductive coating to ensure that the developing roller normally performs imaging, and the conductive coating can be obtained by a mature spraying method, which is conducive to reducing the overall manufacturing cost of the developing roller.

[0019] The thickness of the conductive coating is 10-100 microns, preferably 20-50 microns. When the conductive coating is too thin, the resistance is high, and the electricity is slow to discharge, which affects the imaging quality;Too thick conductive coating will increase the cost, and the surface of the coating is very smooth, which affects the powder effect.

[0020] In order to more clearly illustrate the purpose, technical scheme and advantages of the utility model, the utility model will be further described in detail below with reference to the drawings and specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is the overall structure schematic diagram of the box embodiment;

[0022] Figure 2 It is the exploded structure schematic diagram of the box embodiment;

[0023] Figure 3 It is the radial section structure schematic diagram of the developing roller in the embodiment;

[0024] Figure 4a And 4b It is the axial section structure schematic diagram of the developing roller in the embodiment. DETAILED DESCRIPTION

[0025] In the following description, many specific details are set forth in connection with the implementation in order to provide a thorough understanding of the present application. However, it will be understood by those skilled in the art that the following description and examples are merely illustrative in nature and are not intended to limit the scope of the present application.

[0026] The cartridge according to the present application can be a developing cartridge including a developing roller, or a process cartridge including a developing roller and a photosensitive drum. That is, as long as the cartridge has a developing roller, it falls within the scope of the cartridge according to the present application regardless of the structural form of the cartridge.

[0027] Figure 1 is a schematic view of the overall structure of the cartridge according to an embodiment, Figure 2 is a schematic view of the exploded structure thereof. As shown in Figure 1 and Figure 2 The cartridge 10 according to the embodiment is a developing cartridge including a frame 11 having a developer accommodating chamber provided therein, and a developing roller 12 and a powder feeding roller 13 rotatably provided with respect to the frame 11.

[0028] The developing roller 12 includes a roller shaft 121 and a developer carrying portion 122 ， The developer carrying portion 122 is exposed to the frame 11 so as to be able to supply the developer to the photosensitive drum. Along the axial direction of the developing roller 12, end portion regions of the developer carrying portion 122 are provided with end portion seals 15 with respect to the frame 11, so as to prevent the developer from leaking from the gap between the end portion regions and the frame 11.

[0029] The powder feeding roller 13 is provided inside the frame 11 and can be in elastic contact with the developer carrying portion 122, so as to cause the developer in the developer accommodating chamber to adhere to the surface of the developer carrying portion 122. During the image forming operation, the developer adhering to the surface of the developer carrying portion 122 is supplied to the photosensitive drum, so as to develop the latent electrostatic image on the photosensitive drum.

[0030] For example, along the axial direction of the developing roller 12, the frame 11 is provided with a first support side plate 112 and a second support side plate 113 at both ends thereof, and the roller shaft 121 of the developing roller 12 is rotatably supported on the first support side plate 112 and the second support side plate 113. The first support side plate 112 and the second support side plate 113 can be provided separately from the developing frame 11, or can be integrally formed with the developing frame 11 to constitute a part of the developing frame 11, and the present application is not limited in this regard.

[0031] Further, along the axial direction of the developing roller 12, one axial end portion of the cartridge 10 is provided with a driving head 14 and a gear transmission mechanism. In the case where the cartridge 10 is installed in the electrophotographic image forming apparatus, the driving head 14 can receive a rotational driving force from the electrophotographic image forming apparatus, and drive the developing roller 12 and the powder feeding roller 13 to rotate through the gear transmission mechanism.

[0032] In combination Figure 3 As shown in the embodiment, the developer carrying portion 122 includes an insulating elastomer 122a and a conductive coating 122b. The insulating elastomer 122a is arranged on the outer circumferential surface of the roller shaft 121, and the conductive coating 122b is arranged on the outer circumferential surface of the insulating elastomer 122a. The roller shaft 121 extends from both axial ends of the insulating elastomer 122a, and the extension lengths of the roller shaft 121 from the two ends of the insulating elastomer 122a can be the same or different.

[0033] The roller shaft 121 can be a conductive shaft, such as a conductive metal shaft or a non-metal shaft. The roller shaft 121 can also be a non-conductive shaft, such as a non-conductive shaft obtained by insulating the surface of a conductive metal shaft. Exemplarily, the diameter of the roller shaft 121 (the diameter of the portion in contact with the insulating elastomer 122a) can be 5 mm to 8 mm, and the length of the roller shaft 121 can be 255 mm to 285 mm.

[0034] The insulating elastomer 122a can be made of a non-conductive rubber material, such as non-conductive silicone rubber, polyurethane rubber, nitrile rubber, styrene-butadiene rubber, natural rubber, ethylene-propylene rubber, propylene rubber, and a mixture of the foregoing rubbers, etc., which is not specifically limited in the present application.

[0035] Exemplarily, the outer diameter of the insulating elastomer 122a can be 8 mm to 25 mm, more specifically 10 mm to 20 mm; and the length of the insulating elastomer 122a can be 225 mm to 255 mm. The Shore A hardness of the insulating elastomer 122a is preferably controlled within the range of 58 to 70 degrees, so as to improve the service durability of the developing roller.

[0036] The thickness of the conductive coating 122b can be 10 μm to 100 μm, preferably 20 μm to 50 μm. If the conductive coating 122b is too thin, the resistance is high and the discharging is slow, which affects the imaging quality; if the conductive coating 122b is too thick, the material cost is increased, and the surface of the coating is very smooth, which affects the powdering effect.

[0037] Further, the surface resistance of the conductive coating 122b is preferably controlled within the range of 10 5 Ω to 10 7 Ω, so as to achieve a better conductive effect.

[0038] In the embodiment, as Figure 4a shown, the entire outer circumferential surface of the insulating elastomer 122a can be provided with the conductive coating 122b; or, as Figure 4bAs shown, one or both end regions of the outer circumferential surface of the insulating elastomer 122a has a bare surface 122c which is not covered by the conductive coating 122b. The bare surface 122c can be the surface of the insulating elastomer 122a which is in contact with the end seal 15, and the region where the bare surface 122c is located is the non-exposed working area.

[0039] The conductive coating 122b can be directly provided on the outer circumferential surface of the insulating elastomer 122a, or indirectly provided on the outer circumferential surface of the insulating elastomer 122a, for example, a transition layer is first made on the outer circumferential surface of the insulating elastomer 122a, and then the conductive coating 122b is made on the transition layer, so as to enhance the bonding force between the conductive coating 122b and the insulating elastomer 122a by means of the transition layer.

[0040] The conductive coating 122b can be made by spraying conductive paint. Specifically, the conductive paint used to make the conductive coating 122b is first sprayed on the outer circumferential surface of the insulating elastomer 122a, and then baking or ultraviolet irradiation is performed to solidify the coating to obtain the conductive coating 122b. The conductive paint can be polyurethane paint containing conductive components, but is not limited thereto.

[0041] For example, the developing roller 12 can be obtained by the following method: first, the raw material used to make the insulating elastomer 122a is put into a banbury mixer for mixing, and after mixing, the sheet is obtained by opening the mixer, and after cooling for a predetermined time, the extruder is used to extrude the insulating elastomer 122a according to the size requirement and put it into a heat curing device for heating and curing to obtain a tubular insulating elastomer 122a. Then, the roller shaft 121 is inserted into the tubular core of the insulating elastomer 122a, and after the roller shaft 121 is inserted, the excess part of the insulating elastomer 122a at both ends is cut off according to the size requirement, so as to ensure the length of the insulating elastomer 122a and the flatness of the end surface thereof. Then, the outer circumferential surface of the insulating elastomer 122a is polished on a grinding machine until the product size requirement is met. After polishing, the surface is cleaned to remove the surface powder and impurities, and after drying, the conductive paint is sprayed on the outer circumferential surface of the insulating elastomer 122a, and then the baking oven is used for baking to complete the manufacturing of the developing roller 12. Alternatively, during the extrusion molding of the insulating elastomer 122a, the roller shaft 121 can be embedded at the same time (i.e. the insulating elastomer 122a is extruded on the roller shaft 121) and then heated and cured.

[0042] Please continue to refer to Figure 1 and Figure 2The developing cartridge 10 of the embodiment further comprises a powder discharge blade 16 fixedly installed on the frame 11 and extending along the axial direction of the developing roller 12. Specifically, the powder discharge blade 16 comprises a blade holder 161 connected with the frame 11 and a blade 162 installed on the blade holder 161, the blade 162 being in elastic contact with the conductive coating 122b of the developing roller 12 and capable of controlling the thickness of the developing agent adhered to the surface of the conductive coating 122b. At least the blade 162 of the powder discharge blade 16 is made of a conductive material such as metal, or both the blade holder 161 and the blade 162 are made of a conductive material such as metal. The powder discharge blade 16 can also only comprise a conductive blade 162, in which case the blade 162 is directly fixedly connected to the frame 11.

[0043] Further, the developing cartridge 10 further comprises a developing electrode (not shown in the drawings), which can be located at the same end of the developing cartridge as the drive head 14 or at a different end of the developing cartridge from the drive head 14 in the axial direction of the developing roller 12. The developing electrode can be directly electrically connected with the powder discharge blade 13 or indirectly electrically connected with the powder discharge blade 13 through an intermediate conductive member (such as a wire, a conductive spring or a conductive spring, etc.). In the case where the cartridge 10 is installed in an electrophotographic image forming apparatus, the developing electrode is in contact with a power supply electrode in the main assembly of the image forming apparatus. Therefore, in the case of receiving power from the main assembly of the image forming apparatus, the developing electrode can supply power to the conductive coating 122b through the powder discharge blade 13 to enable the developing roller 12 to perform an imaging operation.

[0044] In the case where only the blade 162 of the powder discharge blade 16 is made of a conductive material and the powder discharge blade 16 only comprises a conductive blade 162, the developing electrode can be directly or indirectly electrically connected to the blade 162; in the case where both the blade holder 161 and the blade 162 of the powder discharge blade 16 are made of a conductive material, the developing electrode can be directly or indirectly electrically connected to any one of the blade holder 161 and the blade 162 or simultaneously electrically connected to both the blade holder 161 and the blade 162.

[0045] Although the present application is described above by way of embodiments, it should be understood that the above embodiments are only used to exemplarily describe the implementable solutions of the present application and should not be interpreted as limiting the protection scope of the present application, i.e. any equivalent replacement or change made by those skilled in the art according to the present application should also be covered by the protection scope of the claims of the present application.

Claims

1. A developer roller comprising a roller shaft; characterized by: The outer circumferential surface of the roller shaft is provided with an insulating elastic body, and the roller shaft is arranged to extend from two axial ends of the insulating elastic body; and the outer circumferential surface of the insulating elastic body is provided with a conductive coating.

2. The developer roller of claim 1, wherein: The conductive coating has a thickness of 10 μm to 100 μm.

3. The developer roller of claim 1, wherein: The surface resistance of the conductive coating is 10 5 Ω ~ 10 7 Ω.

4. The developer roller of claim 1, wherein: The Shore A hardness of the insulating elastic body is 58 to 70 degrees.

5. The developer roller of claim 1, wherein: The entire outer circumferential surface of the insulating elastic body is provided with the conductive coating; or at least one end region of the outer circumferential surface of the insulating elastic body has a bare surface not covered by the conductive coating.

6. The developer roller of claim 1, wherein: The conductive coating is directly arranged on the outer circumferential surface of the insulating elastic body.

7. The developer roller of claim 1, wherein: The roller shaft is a conductive shaft or a non-conductive shaft.

8. The developer roller of claim 1, wherein: The outer diameter of the insulating elastic body is 8 mm to 25 mm, and the length is 225 mm to 255 mm; and the diameter of the roller shaft is 5 mm to 8 mm, and the length is 255 mm to 285 mm.

9. A cartridge for detachable installation to an electrophotographic image forming apparatus; characterized by: The cartridge comprises the developing roller as claimed in any one of claims 1 to 8.

10. The cartridge of claim 9, wherein Further comprising: A powder outlet knife having a blade in elastic electrical contact with the conductive coating; A developing electrode electrically connected to the powder outlet knife and supplying power to the conductive coating through the powder outlet knife.

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