A multi-layered photosensitive drum

Abstract

This invention belongs to the field of electrostatic copying and printing technology, and discloses a multi-layered photosensitive drum. It aims to solve the problems of short service life and unstable image quality caused by surface wear in existing photosensitive drums. The structure includes a cylindrical substrate, and sequentially covering the outer periphery of the substrate with an insulating layer, a selenium-tellurium alloy layer as a hard transition layer, a photosensitive layer as the core functional layer, and a graphene protective layer as the outermost protective layer. This invention constructs a dual wear-resistant protection system by adding a graphene protective layer with ultra-high hardness, extremely low friction coefficient, and high light transmittance outside the photosensitive layer, which works synergistically with the internal selenium-tellurium alloy hard layer. This structure significantly improves the photosensitive drum's resistance to physical wear and chemical corrosion, greatly extending its service life and maintaining stable, high-quality printing results throughout its entire lifespan.

Description

Technical Field

[0001] This utility model relates to the field of electrostatic copying and printing technology, and in particular to a core photoelectric conversion and imaging component used in copiers, printers, multifunction printers and other equipment, specifically a highly durable and long-life multi-layer photosensitive drum. Background Technology

[0002] In modern office equipment such as laser printers and copiers, the photosensitive drum is a core consumable that determines image quality and equipment operating costs. Its basic workflow includes steps such as charging, exposure, development, transfer, cleaning, and static elimination. The surface properties of the photosensitive drum, especially its photoelectric characteristics and mechanical abrasion resistance, directly affect the clarity of the printed matter, color reproduction, and the lifespan of the photosensitive drum itself.

[0003] Currently, the mainstream photosensitive drums on the market are mainly organic photoconductor drums (OPC). OPC drums are relatively inexpensive, but their photosensitive layers are mostly made of organic polymer materials, which have low hardness and are relatively soft. During long-term repeated friction with cleaning blades, toner, and paper, the surface is prone to physical scratches and wear. This wear not only directly forms defects such as black lines and white spots on the printed parts, but also leads to uneven thickness of the photosensitive layer, affecting the stability of the surface potential, thus causing problems such as gray backgrounds and ghosting in the printed image. Furthermore, organic materials are more sensitive to environmental changes, especially under the influence of humidity, temperature fluctuations, and reactive gases such as ozone, which easily cause chemical aging, leading to decreased charge retention and unstable photosensitivity, further shortening the effective lifespan. Therefore, how to improve the environmental stability of photosensitive drums while ensuring long lifespan and wear resistance is a technical challenge that urgently needs to be solved in this field.

[0004] To improve wear resistance, amorphous silicon (a-Si) photosensitive drums also exist. a-Si photosensitive drums have extremely high hardness and a long lifespan, but they usually use complex preparation processes such as plasma-enhanced chemical vapor deposition, which are expensive and result in high costs. They are mostly used in high-end, high-speed professional printing equipment and are difficult to popularize in ordinary commercial and home equipment.

[0005] Therefore, developing a photosensitive drum that can have durability close to or even surpass that of an a-Si drum while keeping costs within a reasonable range to meet the market demand for long-life, highly stable printing consumables is a technical problem that urgently needs to be solved in this field. Utility Model Content

[0006] The purpose of this invention is to overcome the above-mentioned defects of the prior art and provide a multi-layer photosensitive drum with a novel structure that combines the advantages of multiple materials. This photosensitive drum aims to significantly improve the surface's resistance to physical wear and chemical corrosion through its unique hierarchical structure design, thereby achieving an ultra-long service life and durable, stable, high-quality imaging performance.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A multi-layered photosensitive drum comprises, from the inside out: a cylindrical substrate, and an insulating layer, a selenium-tellurium alloy layer, a photosensitive layer, and a graphene protective layer sequentially covering the outer peripheral surface of the substrate.

[0009] Furthermore, the substrate is an aluminum alloy substrate that has undergone precision turning and polishing to ensure excellent electrical conductivity, dimensional stability, and sufficiently low surface roughness. Preferably, 6603 aluminum alloy is used.

[0010] Furthermore, the insulating layer is used to block the injection of charge from the substrate to the photosensitive layer and to cover microscopic defects on the substrate surface. This insulating layer can be a dense alumina film generated on the substrate surface by anodizing, or it can be a coating of polymer resins such as polyester or polycarbonate. Its thickness is preferably 1 to 10 micrometers.

[0011] Furthermore, the selenium-tellurium alloy layer serves as a hard transition layer, disposed between the insulating layer and the photosensitive layer. This layer is typically prepared using physical vapor deposition (PVD) methods such as vacuum evaporation or magnetron sputtering, exhibiting high hardness and wear resistance, while also possessing the ability to regulate charge transport, thus serving the dual purpose of reducing wear and preventing electrostatic accumulation. Its thickness is preferably 0.5 to 2 micrometers.

[0012] Furthermore, the photosensitive layer is the core functional layer for realizing photoelectric conversion. The material is an amorphous selenium (a-Se) based photoconductive material, such as pure selenium, or a selenium alloy doped with tellurium (Te) and arsenic (As) to adjust the spectral response range and thermal stability. Its thickness is preferably 20 to 60 micrometers to ensure sufficient light absorption and charge retention capabilities.

[0013] Furthermore, the graphene protective layer is a key innovation of this invention, serving as the outermost layer directly facing the working environment. This protective layer can be a large-area monolayer or few-layer graphene film grown by chemical vapor deposition (CVD) and then transferred to the surface of the photosensitive drum; alternatively, it can be a composite coating formed by dispersing graphene microflakes, graphene oxide, or reduced graphene oxide in a transparent polymer adhesive and then applying it through spraying, dip coating, or other methods. Its thickness is preferably from 1 nanometer to 1 micrometer.

[0014] Compared with the prior art, this utility model has the following advantages:

[0015] 1. This utility model features a unique dual wear-resistant system of "hard transition layer + top-level protective layer," significantly increasing the design life from the traditional 100,000-stroke level of OPC drums to 500,000 strokes or even higher, approaching the level of a-Si drums. This extended lifespan significantly reduces the frequency of consumable replacements and waste generation, lowering costs for users while also protecting the environment.

[0016] 2. This invention optimizes the multi-layer structure design, effectively improving charge transfer efficiency and significantly reducing residual potential after printing cycles, thus avoiding ghosting and background graying issues. Combined with the high photosensitivity of the amorphous selenium material itself, which serves as the core photosensitive layer, it ensures that the sharpness of image details and the smoothness of color transitions remain at the optimal level during high-speed printing and long-term use.

[0017] 3. The outermost graphene protective layer of this invention possesses excellent chemical inertness, effectively resisting the erosion of the core photosensitive layer by moisture and ozone in the environment, thus overcoming the performance shortcomings of traditional organic photosensitive drums in this regard. This allows the photosensitive drum to maintain stable and reliable working performance under different humidity, temperature, and air quality conditions.

[0018] 4. The structural design of this utility model clearly defines and synergistically enhances the functions of each layer, including substrate support, insulating layer charging, hard layer wear resistance, photosensitive layer imaging, and protective layer protection. This combination achieves ultra-long lifespan and high stability while offering a significant cost advantage over amorphous silicon photosensitive drums, providing the market with a high-performance and economical solution. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the axial cross-section of a multi-layer photosensitive drum according to an embodiment of this utility model.

[0020] In the diagram: 1-substrate; 2-insulating layer; 3-selenium tellurium alloy layer; 4-photosensitive layer; 5-graphene protective layer. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] Please see Figure 1 As shown, this embodiment provides a high-performance, long-life multilayer photosensitive drum, the manufacturing and structural details of which are as follows:

[0023] Step S1, Preparation of substrate 1: Select aluminum alloy tubing of grade 6603 and process it into a cylindrical hollow tube of predetermined size by precision cutting, as substrate 1; then perform diamond turning or precision grinding and polishing on its outer surface to make its surface roughness Ra reach below 0.2 micrometers, so as to ensure the uniformity and adhesion of the subsequent coating.

[0024] Step S2, Formation of Insulating Layer 2: The cleaned aluminum alloy substrate 1 is placed in an electrolyte for anodic oxidation treatment, and a dense aluminum oxide (Al2O3) film with a thickness of approximately 5 micrometers is grown in situ on its outer surface to form insulating layer 2; this layer can effectively cover all microscopic defects on the substrate surface, providing up to 10 14 The volume resistivity of Ω·cm prevents charge leakage during subsequent charging.

[0025] Step S3, Deposition of selenium-tellurium alloy layer 3: The substrate with insulating layer 2 is placed in a vacuum coating equipment; using magnetron sputtering technology, a selenium-tellurium alloy layer 3 with a thickness of about 1 micrometer is deposited on the surface of insulating layer 2 in an argon atmosphere with a selenium-tellurium alloy target; this layer is hard and serves as a hard transition layer, providing mechanical support for the photosensitive layer above.

[0026] Step S4, Deposition of photosensitive layer 4: In the same vacuum system, an amorphous selenium arsenide (a-Se:As) alloy with a thickness of 50 micrometers is deposited on the selenium telluride alloy layer 3 as photosensitive layer 4 by vacuum evaporation. This layer is the core of the photosensitive drum and has excellent photoconductivity.

[0027] Step S5, Formation of graphene protective layer 5: A high-quality monolayer graphene film is grown on a copper foil catalyst using chemical vapor deposition (CVD). Then, the complete graphene film is precisely covered and attached to the outer surface of the photosensitive layer 4 using wet transfer technology. After removing the auxiliary transfer layer and drying, a uniform and dense graphene protective layer 5 with a thickness of only about 1 nanometer is formed on the outermost layer of the photosensitive drum. This layer has atomic-level flatness, excellent thermal conductivity, extremely low coefficient of friction, and optical transparency greater than 97%.

[0028] The working principle of this invention in actual use is as follows: When the photosensitive drum manufactured in this embodiment works in the printer, the charging roller first uniformly applies a negative charge to its surface. The laser beam emitted by the laser, based on the image data, passes through the transparent graphene protective layer 5 and irradiates the photosensitive layer 4. The photogenerated electron-hole pairs in the irradiated area separate and move under the action of the electric field, neutralizing the negative charge on the surface, forming a potential difference, and constituting an electrostatic latent image. Subsequently, the positively charged toner is attracted to the unexposed area that retains a negative charge. When the paper passes by, the toner image is transferred onto the paper. Finally, the cleaning blade removes the residual toner from the surface of the photosensitive drum. During this process, the graphene protective layer 5, with its extremely high hardness and lubricity, protects the photosensitive layer 4 from wear by the cleaning blade, thereby completing one printing cycle.

[0029] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any modifications or alterations made by those skilled in the art to the technical solution of the present utility model by means of equivalent substitution or equivalent transformation, without departing from the scope of the technical solution described herein, should be covered within the protection scope of the present utility model.

Claims

1. A multi-layered photosensitive drum, characterized in that, It includes a cylindrical substrate (1), and an insulating layer (2), a selenium-tellurium alloy layer (3), a photosensitive layer (4), and a graphene protective layer (5) sequentially covering the outer peripheral surface of the substrate (1).

2. The multi-layer photosensitive drum according to claim 1, characterized in that, The substrate (1) is a precision-machined aluminum alloy substrate.

3. The multi-layer photosensitive drum according to claim 2, characterized in that, The aluminum alloy substrate (1) is made of 6603 aluminum alloy material.

4. The multi-layer photosensitive drum according to claim 1, characterized in that, The insulating layer (2) is a dense alumina film or polymer resin coating generated on the substrate surface by anodizing process, with a thickness of 1 to 10 micrometers.

5. A multi-layered photosensitive drum according to claim 1, characterized in that, The selenium-tellurium alloy layer (3) is formed by physical vapor deposition and has a thickness of 0.5 to 2 micrometers.

6. A multi-layered photosensitive drum according to claim 1, characterized in that, The photosensitive layer (4) is an amorphous selenium-based photoconductive material layer with a thickness of 20 to 60 micrometers.

7. A multi-layer photosensitive drum according to claim 1, characterized in that, The graphene protective layer (5) is a single-layer or few-layer graphene film, or a transparent composite coating containing graphene microflakes.

8. A multi-layer photosensitive drum according to claim 7, characterized in that, The thickness of the graphene protective layer (5) is 1 nanometer to 1 micrometer.

9. A multi-layered photosensitive drum according to claim 1, characterized in that, The graphene protective layer (5) has an optical transparency of more than 97%.

Images