Optical fiber image inverter, its preparation method and application

Abstract

The application discloses a fiber inverter and a preparation method and application thereof. The preparation method comprises the following steps: arranging monofilaments into a regular hexagon in a closest packing mode, inserting light-absorbing filaments in a regular triangle and white filaments in a regular triangle into gaps between the monofilaments to obtain a primary composite rod; the monofilaments are composed of a glass core and a glass skin layer wrapped on the surface of the glass core; drawing the primary composite rod into a primary multifilament according to a primary reduction ratio; arranging the primary multifilament into a regular hexagon in a closest packing mode to obtain a secondary composite rod; drawing the secondary composite rod into a secondary multifilament according to a secondary reduction ratio; and manufacturing the secondary multifilament into the fiber inverter; wherein the primary reduction ratio is smaller than the secondary reduction ratio. The method can reduce requirements for temperature and furnace temperature system in the pressing plate and twisting processes, simultaneously improves black and white grids of the fiber inverter, solves the problem of edge resolution disappearance, and improves the qualified rate of finished products, and is more suitable for practical use.

Description

Technical Field

[0001] This invention relates to the field of fiber optic image transmission element manufacturing, and particularly to a fiber optic image inverter, its preparation method, and its application. Background Technology

[0002] Fiber optic image inverters can transmit images 180° in reverse, featuring high resolution, clear transmission, small size, and light weight. They are primarily used to replace relay lens systems in low-light night vision devices and are also widely used in devices requiring image inversion, finding applications in military, criminal investigation, aerospace, and medical fields.

[0003] A fiber optic image reversal device is formed by thermally twisting a fiber optic blank by 180°. Theoretically, only the fiber at the axis is not twisted or stretched; the rest of the fiber is twisted and stretched into biconical fibers coiled at different helical angles around the axis by 180°. The farther away from the axis, the longer the coiling distance, the greater the stretching, the greater the curvature, and the larger the resulting taper.

[0004] The fabrication of fiber optic image converters places extremely high demands on the temperature and furnace temperature system during the torsion and pressing processes. At the same time, fiber optic image converters are prone to defects such as the loss of grid and edge resolution, resulting in a low product yield. Summary of the Invention

[0005] The main objective of this invention is to provide an optical fiber image reversal device, its preparation method, and its application. The technical problem to be solved is how to prepare the optical fiber image reversal device, reduce the requirements for temperature and furnace temperature system during the pressing and twisting process, improve the black and white grid of the optical fiber image reversal device, solve the problem of edge resolution loss, improve the yield of finished products, and thus make it more suitable for practical use.

[0006] The objective of this invention and the technical problem it solves are achieved through the following technical solution. A method for fabricating an optical fiber image inverter according to this invention includes the following steps:

[0007] (1) A regular hexagon is formed by arranging monofilaments in the closest packing manner, and a light-absorbing filament and a white filament of equilateral triangle are inserted into the gaps between the monofilaments to obtain a primary composite rod; the monofilaments are composed of a glass core and a glass skin layer wrapped around the surface of the glass core.

[0008] (2) The aforementioned primary composite rod is drawn into a primary multifilament according to the primary reduction ratio;

[0009] (3) Arrange the aforementioned primary multifilaments into a hexagon using the closest packing method to obtain a secondary composite rod; draw the aforementioned secondary composite rod into secondary multifilaments according to the secondary scaling ratio; and,

[0010] (4) The aforementioned secondary multifilament is used to make an optical fiber image inverter;

[0011] The aforementioned first-order scaling value is smaller than the aforementioned second-order scaling value.

[0012] Preferably, the material of the aforementioned equilateral triangular white filament is the same as the material of the aforementioned glass core.

[0013] Preferably, the diameter of the aforementioned equilateral triangular light-absorbing filament and the diameter of the aforementioned equilateral triangular white filament are 0.178-0.205 times the diameter of the aforementioned single filament.

[0014] Preferably, the aforementioned primary scaling factor is equal to the aforementioned secondary scaling factor of 0.75 to 0.95.

[0015] Preferably, the aforementioned primary scaling factor is 0.033 to 0.036, and the aforementioned secondary scaling factor is 0.035 to 0.04.

[0016] Preferably, in step (1) above, the aforementioned regular hexagon is composed of 217 of the aforementioned monofilaments, with 9 of the aforementioned monofilaments on each side;

[0017] In step (3), the aforementioned regular hexagon is composed of 469 of the aforementioned primary multifilaments, with 13 of the aforementioned primary multifilaments on each side.

[0018] Preferably, the method for manufacturing the aforementioned optical fiber image converter from the aforementioned secondary multifilament is as follows: the aforementioned secondary multifilament is cut to a fixed length and arranged into plate segments, then melt-pressed at a compression ratio of 0.75 to 0.95, rolled into a round shape, to obtain an optical fiber blank; the aforementioned optical fiber blank is sliced ​​and then twisted at both ends by 180° to obtain the aforementioned optical fiber image converter.

[0019] Preferably, the light-absorbing glass used in the aforementioned equilateral triangular light-absorbing filament is composed of the following components in molar percentage: SiO2: 71-80.0%; Al2O3: 0.5-5.0%; B2O3: 1.0-5.0%; Na2O: 1.0-11.0%; K2O: 6.0-11.0%; MgO: 0.1-2.0%; CaO: 0.1-2.0%; BaO: 0-0.04%; TiO2: 0-1.0%; Co2O3: 0.1-0.4%; NiO: 0.1-1.0%; MnO: 1.0-5.0%; V2O5: 0.1-1.0%; CeO2: 0-0.2%; and CuO: 0-0.05%.

[0020] The objective of this invention and the technical problem it solves are achieved by the following technical solution. An optical fiber image inverter according to this invention is prepared using any of the aforementioned fabrication methods.

[0021] The objective of this invention and the technical problem it solves are achieved by the following technical solution. According to this invention, an image transmission device includes the aforementioned fiber optic image inverter.

[0022] By employing the above technical solution, the fiber optic image inverter, its fabrication method, and its application proposed in this invention have at least the following advantages:

[0023] (I) The fiber optic image converter fabrication method proposed in this invention inserts equilateral triangular light-absorbing wires and equilateral triangular white wires into the gaps between the single wires. On the one hand, the three pillars of each absorption wire and white wire provide support for the surrounding unit wires, which can effectively ensure the roundness of each unit wire during multiple heat treatments, thereby effectively ensuring the roundness of the unit bundle, improving the black and white grid of the fiber optic image converter and solving the problem of edge resolution loss. On the other hand, the use of equilateral triangular light-absorbing wires achieves a greater degree of filling of the gaps, which is equivalent to increasing the unit volume of the light-absorbing wires. The contrast of the panel can be adjusted using fewer light-absorbing wires.

[0024] (II) The fiber optic image reversing method proposed in this invention involves drawing a primary composite rod into a primary multifilament according to a primary scaling ratio, and a secondary composite rod into a secondary multifilament according to a secondary scaling ratio. During these two drawing processes, the primary scaling ratio is controlled to be smaller than the secondary scaling ratio, making the primary scaling ratio as small as possible and the secondary scaling ratio as large as possible. During the furnace melting process, the high temperature forms a strengthening layer on the surface, generating shear stress, which causes the unit wires on the surface to undergo lateral elliptic deformation. The larger the scaling ratio, the greater the elliptic deformation, and the more planar the surface tends to be. Under the same total scaling ratio, controlling the primary scaling ratio to be smaller and the secondary scaling ratio to be larger ensures the roundness of the prepared primary multifilament and its unit wires, thereby ensuring the roundness of the outer unit wires of the secondary composite rod formed by arranging the primary multifilaments, and further ensuring the roundness of the outer unit wires of the secondary multifilament drawn from the secondary composite rod, improving the black-and-white grid of the fiber optic image reversing and solving the problem of edge resolution loss. However, when the primary scaling ratio is greater than the secondary scaling ratio, the aforementioned effect is not achieved, and the prepared fiber optic image reversing is prone to grid and edge resolution loss problems.

[0025] (III) The fiber optic image converter fabrication method proposed in this invention inserts equilateral triangular light-absorbing wires and equilateral triangular white wires into the gaps between the single wires, and controls the first scaling ratio to be less than the second scaling ratio. This effectively ensures the roundness of each unit wire during multiple heat treatments, effectively reduces the requirements of temperature and furnace temperature system during pressing and twisting, improves the black and white grid of the fiber optic image converter and solves the problem of edge resolution loss, and increases the yield of finished products, thus making it more suitable for practical use.

[0026] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0027] Figure 1 A schematic diagram of a primary composite rod provided in an embodiment of the present invention;

[0028] In the diagram: 1 is a monofilament, and 2 is an equilateral triangular light-absorbing filament. Detailed Implementation

[0029] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, provides a detailed description of the specific implementation, structure, features, and effects of an optical fiber image inverter, its fabrication method, and its application based on the present invention. In the following description, different "embodiments" or "embodiments" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable manner.

[0030] The present invention proposes a method for fabricating an optical fiber image inverter, comprising the following steps:

[0031] (1) As Figure 1 As shown, monofilament 1 is arranged into a regular hexagon in the closest packing manner, and equilateral triangular light-absorbing filament 2 and equilateral triangular white filament are inserted into the gaps between monofilament 1 to obtain a primary composite rod; monofilament 1 consists of a glass core and a glass skin layer wrapped around the surface of the aforementioned glass core.

[0032] (2) The aforementioned primary composite rod is drawn into a primary multifilament according to the primary reduction ratio;

[0033] (3) Arrange the aforementioned primary multifilaments into a hexagon using the closest packing method to obtain a secondary composite rod; draw the aforementioned secondary composite rod into a secondary multifilament according to the secondary reduction ratio;

[0034] (4) The aforementioned secondary multifilament is used to make an optical fiber image inverter;

[0035] The aforementioned first-order scaling value is smaller than the aforementioned second-order scaling value.

[0036] In step (1), equilateral triangular light-absorbing wires 2 and equilateral triangular white wires are inserted into the gaps of single wire 1; wherein, the control principle for the number and position of the inserted light-absorbing wires is the same as that for the number and position of the inserted light-absorbing wires with circular cross-sections in the prior art; the number of inserted light-absorbing wires is mainly determined according to the contrast requirements of the fiber optic image converter; in order to ensure that the fiber optic image converter has good anti-stray crosstalk performance, the contrast of the fiber optic image converter is generally controlled to be less than 1, and the present invention preferably controls the number of equilateral triangular light-absorbing wires to account for 40% to 60% of the number of single wires; the insertion position of the equilateral triangular light-absorbing wires is determined according to the principle of the prior art. The invention does not impose specific limitations; the wires can be randomly inserted to ensure a roughly uniform distribution. The technical purpose of using equilateral triangular wires in this invention is twofold: First, the three prisms of each equilateral triangular wire provide support for the surrounding unit wires, effectively ensuring the roundness of each unit wire during multiple heat treatments, thereby effectively ensuring the roundness of the unit bundle, improving the black-and-white grid of the fiber optic image converter, and solving the problem of edge resolution loss. Second, the use of equilateral triangular light-absorbing wires achieves a greater degree of filling of gaps, which is equivalent to increasing the volume of a single light-absorbing wire, allowing for adjustment of panel contrast using fewer light-absorbing wires.

[0037] Monofilament 1 consists of a glass core and a glass skin covering the surface of the glass core. Monofilament 1 is prepared by matching and nesting the core glass rod and the skin glass tube and then drawing them, or by coating the surface of the glass core with the aforementioned glass skin material. The refractive index of the glass core is greater than 1.8, and the refractive index of the glass skin is less than 1.5.

[0038] In steps (2) and (3), the primary composite rod is drawn into a primary multifilament according to the primary reduction ratio, and the secondary composite rod is drawn into a secondary multifilament according to the secondary reduction ratio. Wherein, the primary reduction ratio = the diameter of the primary multifilament / the opposite side of the primary composite rod; the secondary reduction ratio = the diameter of the secondary multifilament / the opposite side of the secondary composite rod.

[0039] During these two drawing processes, the primary scaling ratio is controlled to be smaller than the secondary scaling ratio, making the primary scaling ratio as small as possible and the secondary scaling ratio as large as possible. During the furnace melting process, high temperatures form a reinforcing layer on the surface, generating shear stress. This causes the surface unit wires to undergo lateral elliptic deformation. The larger the scaling ratio, the greater the elliptic deformation, and the more planar the surface becomes. With the same total scaling ratio, controlling the primary scaling ratio to be smaller and the secondary scaling ratio to be larger ensures the roundness of the prepared primary multifilament and its unit wires. This, in turn, ensures the roundness of the outer unit wires of the secondary composite rod formed by arranging the primary multifilaments, and further ensures the roundness of the outer unit wires of the secondary multifilament drawn from the secondary composite rod. This improves the black-and-white grid of the fiber optic image converter and solves the problem of edge resolution loss. However, when the primary scaling ratio is greater than the secondary scaling ratio, the aforementioned effects are not achieved, and the prepared fiber optic image converter is prone to black-and-white grid problems and edge resolution loss.

[0040] The fiber optic image reversal method proposed in this invention effectively ensures the roundness of each unit filament during multiple heat treatments by inserting equilateral triangular light-absorbing filaments and equilateral triangular white filaments into the gaps between the single filaments and controlling the primary scaling ratio to be less than the secondary scaling ratio. This effectively reduces the requirements of the temperature and furnace temperature system during the pressing and twisting processes, while improving the black and white grid of the fiber optic image reversal and solving the problem of edge resolution loss, thereby increasing the yield of the finished product and making it more suitable for practical use.

[0041] In some embodiments, the material of the aforementioned equilateral triangular white filament is the same as the material of the aforementioned glass core. When the material of the equilateral triangular white filament is the same as the material of the glass core, on the one hand, the equilateral triangular white filament and the glass skin layer on the outer surface of the adjacent monofilament 1 form a triangular unit filament. Although it does not provide image transmission for a single unit, it can improve the overall transmittance of the panel and reduce stray light. On the other hand, the glass core material has a higher softening temperature, which allows the equilateral triangular white filament to provide more support during heat treatment. Combining the above two aspects, using the glass core material for the equilateral triangular white filament can improve the problem of the loss of black and white grid and edge resolution in the image reverser after fiber twisting.

[0042] In some embodiments, the diameter of the equilateral triangular light-absorbing filament 2 and the diameter of the aforementioned equilateral triangular white filament are 0.178-0.205 times the diameter of the single filament 1. The diameter of the equilateral triangular filament is equal to the height of the equilateral triangle. The equilateral triangular light-absorbing filament 2 and the equilateral triangular white filament can fill the gaps between the single filaments 1, and the diameter of the equilateral triangular filament is determined based on the gaps between the single filaments 1. If the diameter of the equilateral triangular filament is too large, it will affect the shape of the hexagon formed by the stacking of single filaments 1; if the diameter of the equilateral triangular filament is too small, it will not provide sufficient support and will not be able to guarantee the roundness of the unit filaments and unit bundles. Therefore, the diameter of the equilateral triangular light-absorbing filament 2 and the aforementioned equilateral triangular white filament are controlled to be 0.178-0.205 times the diameter of the single filament 1.

[0043] In some embodiments, the aforementioned first scaling factor plus the aforementioned second scaling factor equals 0.75 to 0.95. Using this range is beneficial for improving the black-and-white grid of the fiber optic image inverter and resolving the problem of edge resolution loss.

[0044] In some embodiments, the aforementioned primary scaling factor is 0.033 to 0.036, and the aforementioned secondary scaling factor is 0.035 to 0.04. By using primary and secondary scaling factor values ​​within this range, a smaller overall scaling factor can be achieved while improving the black-and-white grid of the fiber optic image inverter and resolving the problem of edge resolution loss.

[0045] In some embodiments, in step (1), the aforementioned regular hexagon is composed of 217 single filaments 1 arranged together, with 9 single filaments 1 on each side; in step (3), the aforementioned regular hexagon is composed of 469 of the aforementioned primary multifilaments arranged together, with 13 of the aforementioned primary multifilaments 1 on each side. Experimental verification shows that the regular hexagonal structure with 9 single filaments 1 on each side of the primary composite rod can effectively improve the deformation of the unit filaments at the boundary of the unit filament bundle and the diffusion and crosstalk problems between the internal unit filaments during the blank making and twisting process, thereby improving the problem of black and white grids appearing in the image transmission of the inverter after twisting. Experimental verification shows that the regular hexagonal structure with 13 primary multifilaments 1 on each side of the secondary composite rod can effectively improve the deformation of the unit filaments at the boundary of the unit filament bundle and the diffusion and crosstalk problems between the internal unit filaments during the blank making and twisting process, thereby improving the problem of black and white grids appearing in the image transmission of the inverter after twisting.

[0046] In some embodiments, the method for fabricating an optical fiber image converter from the aforementioned secondary multifilament is as follows: the aforementioned secondary multifilament is cut to a fixed length and arranged into plate segments, then melt-pressed at a compression ratio of 0.75 to 0.95, rolled into a round shape, to obtain an optical fiber blank; the aforementioned optical fiber blank is sliced ​​and then twisted at both ends by 180° to obtain the aforementioned optical fiber image converter.

[0047] In some embodiments, the light-absorbing glass used in the aforementioned equilateral triangular light-absorbing filament is composed of the following components in molar percentage: SiO2: 71-80.0%; Al2O3: 0.5-5.0%; B2O3: 1.0-5.0%; Na2O: 1.0-11.0%; K2O: 6.0-11.0%; MgO: 0.1-2.0%; CaO: 0.1-2.0%; BaO: 0-0.04%; TiO2: 0-1.0%; Co2O3: 0.1-0.4%; NiO: 0.1-1.0%; MnO: 1.0-5.0%; V2O5: 0.1-1.0%; CeO2: 0-0.2%; and CuO: 0-0.05%.

[0048] In the aforementioned light-absorbing glass, SiO2 is the main component forming the glass framework and plays a major role in the framework. The molar percentage (mol.%) of SiO2 is 71.0-80.0%. When the SiO2 content is below 71.0 mol.%, it is difficult to obtain a coefficient of thermal expansion similar to that of the blister glass, and it will also reduce the chemical stability of the glass; when the SiO2 content is above 80.0 mol.%, the high-temperature viscosity of the glass will increase, resulting in excessively high glass melting temperature.

[0049] Al₂O₃ is an intermediate oxide of glass. 3+ There are two coordination states: located in tetrahedra or octahedra. When there is enough oxygen in the glass, aluminum-oxygen tetrahedra [AlO4] are formed, forming a continuous network with silicon-oxygen tetrahedra. When there is insufficient oxygen in the glass, aluminum-oxygen octahedra [AlO6] are formed, which are the outer bodies of the network and are located in the vacancies of the silicon-oxygen network. Therefore, within a certain content range, it can be the main body for glass network formation along with SiO2. The molar percentage (mol.%) of Al2O3 is 0.5-5.0. An Al2O3 content greater than 5.0 mol.% will significantly increase the high-temperature viscosity of the glass, thus raising the melting temperature of the glass.

[0050] B₂O₃ is a glass-forming oxide and a component of the glass framework. It also acts as a flux to reduce the viscosity of molten glass. Boron trigonal [BO₃] and boron-oxygen tetrahedron [BO₄] are structural components. Under different conditions, boron may exist as trigonal [BO₃] or boron-oxygen tetrahedron [BO₄]. At high-temperature melting conditions, it is generally difficult to form boron-oxygen tetrahedra, and it can only exist as trihedrons. However, at low temperatures, under certain conditions, boron… 3+ B₂O₃ tends to capture free oxygen to form tetrahedrons, resulting in a more compact structure and increased low-temperature viscosity of the glass. However, due to its properties of decreasing glass viscosity at high temperatures and increasing it at low temperatures, and its role as a major component in reducing the glass's refractive index, its content range is relatively small. The molar percentage (mol.%) of B₂O₃ is 1.0-5.0. A B₂O₃ content greater than 5.0 mol.% will increase the glass's tendency to undergo phase separation.

[0051] Na2O is an oxide on the outer layer of a glass structure network. The molar percentage (mol.%) of Na2O is 1.0-11.0. When the Na2O content is greater than 11.0 mol.%, it will increase the coefficient of thermal expansion of the glass.

[0052] K2O is an oxide in the glass structure network. The molar percentage (mol.%) of K2O is 6.0-11.0. When the K2O content is greater than 11.0 mol.%, it will increase the coefficient of thermal expansion of the glass.

[0053] MgO is an oxide on the glass network and is used to regulate the crystallization temperature of glass. The molar percentage (mol.%) of MgO is 0.1-2.0. An MgO content greater than 2.0 mol.% increases the glass's tendency to crystallize. CaO is also an oxide on the glass network. The molar percentage (mol.%) of CaO is 0.1-2.0. A CaO content greater than 2.0 mol.% reduces the glass's chemical stability and increases its tendency to crystallize.

[0054] BaO is an external oxide of the glass structure network, used to regulate the crystallization temperature of glass. The molar percentage (mol.%) of BaO is 0-0.04. A BaO content greater than 0.04 mol.% will reduce the chemical stability of the glass and increase its tendency to crystallize.

[0055] TiO2 is used to adjust the chemical resistance and crystallization tendency of glass. The molar percentage (mol.%) of TiO2 is 0-1.0. If the TiO2 content is greater than 1.0 mol.%, it will reduce the chemical resistance of the glass and increase the tendency to crystallize.

[0056] Co2O3 is a colorant for light-absorbing glass. The molar percentage (mol.%) of Co2O3 is 0.1-0.4%. Co2O3 has a lower melting point than CoO, allowing it to combine with other coloring ions to form a stable morphology within the glass, thus making the coloring of the light-absorbing material more stable. When the Co2O3 content exceeds 0.4 mol.%, it reduces the chemical stability of the glass and increases its tendency to crystallize.

[0057] NiO is a colorant for light-absorbing glass, with a molar percentage (mol.%) of 0.1-1.0. 2+ It has good absorption in the visible light region. However, if the NiO content is greater than 1.0 mol.%, it will reduce the chemical stability of the glass and increase the tendency of the glass to crystallize.

[0058] MnO is a colorant for light-absorbing glass. In this invention, MnO plays a major role as the light absorber. MnO has a higher melting point than MnO2, and Mn... 2+ It has stable light absorption capacity between 400-700nm and can form stable color in glass. The molar percentage (mol.%) of MnO is 1.0-5.0. If the MnO content is greater than 5.0 mol.%, it will reduce the chemical stability of the glass and increase the tendency of the glass to crystallize.

[0059] V₂O₅ is a colorant for light-absorbing glass. The molar percentage (mol.%) of V₂O₅ is 0.1-1.0. V₂O₅ can solidify manganese ions for coloring, thus making the coloring of light-absorbing glass more stable. When the V₂O₅ content is greater than 1.0 mol.%, it will reduce the chemical stability of the glass and increase the tendency of the glass to crystallize.

[0060] CeO2 is a rare earth oxide, mainly used to regulate the crystallization properties of glass and act as a glass clarifying agent. The molar percentage (mol.%) of CeO2 is 0-0.2. When the CeO2 content is greater than 0.2 mol.%, it will increase the tendency of glass to crystallize.

[0061] CuO is a colorant for light-absorbing glass and can react with Ni. 2+ Co 3+ Mn 2+ By combining these elements, a stable coloring is formed in the glass. Utilizing the composite absorption effect, it is possible to ensure the absorption of stray light in the wavelength range of 400nm-700nm, achieving a better light absorption effect. This ensures that the light absorption curve does not show obvious transmission peaks in the visible light region. The molar percentage (mol.%) of CuO is 0-0.05, but if the CuO content is greater than 0.05 mol.%, it will increase the tendency of the glass to crystallize.

[0062] The aforementioned light-absorbing glass exhibits excellent contrast performance adjustment for fiber optic image inverters. With a thickness of 0.5±0.01mm, it possesses strong and uniform light absorption capability and spectral absorption effect within the wavelength range of 510-660nm, with a spectral transmittance ≤3.0%. The use of this light-absorbing glass in this invention can enhance the contrast and clarity of fiber optic image inverters.

[0063] The fiber optic image inverter proposed in this invention is prepared by any of the aforementioned preparation methods.

[0064] The present invention provides an image transmission device comprising the aforementioned fiber optic image inverter. This fiber optic image inverter can be applied in low-light image intensifiers.

[0065] The present invention will be further described below with reference to specific embodiments, but this should not be construed as a limitation on the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention still fall within the scope of protection of the present invention.

[0066] Unless otherwise specified, all materials and reagents mentioned below are commercially available products well known to those skilled in the art; unless otherwise specified, all methods described are methods known in the art. Unless otherwise defined, the technical or scientific terms used should have the ordinary meaning understood by those skilled in the art to which this invention pertains.

[0067] The test methods used in the following examples and comparative examples are as follows:

[0068] Contrast Ratio Test: Contrast ratio is used to characterize the stray light crosstalk performance of the fiber optic imaging element under test. The transmittance of the fiber optic imaging element is collected under both bright and dark conditions, then processed to obtain the grayscale value of each pixel. Normalization is then performed to obtain the normalized transmittance value at any given location; this value is the contrast ratio. A smaller contrast ratio indicates better stray light crosstalk resistance of the fiber optic imaging element. A contrast ratio less than 1 is considered high contrast.

[0069] Black / White Screen Test: Under a 10X microscope lens, place the fiber optic image inverter under test on green glass (wavelength 495-570nm). Observe the image formed by light passing through the green glass and the fiber optic image inverter under the microscope with the naked eye. A black screen appears as a defect with low edge transmittance, with the secondary multifilament as the unit; a white screen appears as a defect with high edge transmittance, with the secondary multifilament as the unit. The testing standard is that no obvious bright and dark boundary is observed under a 10X microscope, which is considered acceptable.

[0070] Resolution test: Under a 10X microscope lens, place the fiber optic image inverter on the resolution reticle and observe the smallest resolvable area with the naked eye to compare the resolution value.

[0071] In the following examples and comparative examples, the core glass rod is made of glass with a refractive index of 1.81; the outer glass tube is made of glass with a refractive index of 1.49; and the molar percentage composition of the light-absorbing glass is as follows: SiO2: 76.00%; Al2O3: 2.00%; B2O3: 3.5%; Na2O: 5.10%; K2O: 8.20%; MgO: 0.30%; CaO: 1.70%; BaO: 0.02%; TiO2: 0.02%; Co2O3: 0.20%; NiO: 0.50%; MnO: 1.90%; V2O5: 0.45%; CeO2: 0.06%; CuO: 0.05%.

[0072] Example 1

[0073] A core glass rod with a diameter of 30 mm and a sheath glass tube with a thickness of 4.5 mm are matched and drawn to obtain a monofilament with a diameter of 2.00 mm; the light-absorbing glass is made into an equilateral triangular light-absorbing filament with a diameter of 0.410 mm; the core glass is made into an equilateral triangular white filament with a diameter of 0.410 mm.

[0074] Arrange 217 monofilaments into a hexagon with 9 monofilaments on each side. Insert 90 light-absorbing filaments into the gaps between the monofilaments to make the light-absorbing filaments evenly distributed within the cross-section of the hexagon. Insert white filaments into the remaining gaps to obtain a primary composite rod. Draw the primary composite rod into a primary multifilament at a scaling ratio of 0.033.

[0075] A secondary composite rod is obtained by arranging 469 primary multifilaments into a hexagon with 13 primary multifilaments on each side, and then drawing it into a secondary multifilament according to a reduction ratio of 0.04.

[0076] After the secondary multifilaments are cut to a fixed length and arranged into plate segments, they are melt-pressed into shape with a compression ratio of 0.95. After rolling, they are processed to obtain an optical fiber blank. The optical fiber blank is sliced ​​and then twisted at both ends by 180° to obtain an optical fiber image converter with a unit wire diameter of 2.5 micrometers.

[0077] Example 2

[0078] A core glass rod with a diameter of 30 mm and a sheath glass tube with a thickness of 4.5 mm are matched and drawn to obtain a monofilament with a diameter of 2.60 mm; the light-absorbing glass is made into an equilateral triangular light-absorbing filament with a diameter of 0.530 mm; the core glass is made into an equilateral triangular white filament with a diameter of 0.530 mm.

[0079] Arrange 217 monofilaments into a hexagon with 9 monofilaments on each side. Insert 100 light-absorbing filaments into the gaps between the monofilaments to make the light-absorbing filaments evenly distributed within the cross-section of the hexagon. Insert white filaments into the remaining gaps to obtain a primary composite rod. Draw the primary composite rod into a primary multifilament at a scaling ratio of 0.036.

[0080] A secondary composite rod is obtained by arranging 469 primary multifilaments into a hexagon with 13 primary multifilaments on each side, and then drawing it into a secondary multifilament according to a reduction ratio of 0.04.

[0081] After the secondary multifilaments are cut to a fixed length and arranged into plate segments, they are melt-pressed into shape with a compression ratio of 0.80. After rounding, they are processed to obtain an optical fiber blank. The optical fiber blank is sliced ​​and then twisted at both ends by 180° to obtain an optical fiber image converter with a unit wire diameter of 3 micrometers.

[0082] Example 3

[0083] A core glass rod with a diameter of 30 mm and a sheath glass tube with a thickness of 4.5 mm are matched and drawn to obtain a monofilament with a diameter of 2.80 mm; the light-absorbing glass is made into an equilateral triangular light-absorbing filament with a diameter of 0.570 mm; the core glass is made into an equilateral triangular white filament with a diameter of 0.570 mm.

[0084] Arrange 217 monofilaments into a hexagon with 9 monofilaments on each side. Insert 90 light-absorbing filaments into the gaps between the monofilaments to make the light-absorbing filaments evenly distributed within the cross-section of the hexagon. Insert white filaments into the remaining gaps to obtain a primary composite rod. Draw the primary composite rod into a primary multifilament at a scaling ratio of 0.033.

[0085] A secondary composite rod is obtained by arranging 469 primary multifilaments into a hexagon with 13 primary multifilaments on each side, and then drawing it into secondary multifilaments according to a reduction ratio of 0.035.

[0086] After the secondary multifilaments are cut to a fixed length and arranged into plate segments, they are melt-pressed into shape with a compression ratio of 0.95. After rolling, they are processed to obtain an optical fiber blank. The optical fiber blank is sliced ​​and then twisted at both ends by 180° to obtain an optical fiber image converter with a unit wire diameter of 3.1 micrometers.

[0087] Example 4

[0088] A core glass rod with a diameter of 30 mm and a sheath glass tube with a thickness of 4.0 mm are matched and drawn to obtain a monofilament with a diameter of 2.80 mm; the light-absorbing glass is made into an equilateral triangular light-absorbing filament with a diameter of 0.570 mm; the core glass is made into an equilateral triangular white filament with a diameter of 0.570 mm.

[0089] Arrange 169 monofilaments into a hexagon with 8 monofilaments on each side. Insert 90 light-absorbing filaments into the gaps between the monofilaments to make the light-absorbing filaments evenly distributed within the cross-section of the hexagon. Insert white filaments into the remaining gaps to obtain a primary composite rod. Draw the primary composite rod into a primary multifilament at a scaling ratio of 0.034.

[0090] A secondary composite rod is obtained by arranging 469 primary multifilaments into a hexagon with 13 primary multifilaments on each side, and then drawing it into secondary multifilaments according to a reduction ratio of 0.045.

[0091] After the secondary multifilaments are cut to a fixed length and arranged into plate segments, they are melt-pressed into shape with a compression ratio of 0.9. After rolling and processing, an optical fiber blank is obtained. The optical fiber blank is sliced ​​and then twisted at both ends by 180° to obtain an optical fiber image converter with a unit wire diameter of 4 micrometers.

[0092] Example 5

[0093] A core glass rod with a diameter of 30 mm and a sheath glass tube with a thickness of 3.6 mm are matched and drawn to obtain a monofilament with a diameter of 3.2 mm; the light-absorbing glass is made into an equilateral triangular light-absorbing filament with a diameter of 0.570 mm; the core glass is made into an equilateral triangular white filament with a diameter of 0.570 mm.

[0094] Arrange 91 monofilaments into a hexagon with 6 monofilaments on each side. Insert 50 light-absorbing filaments into the gaps between the monofilaments to make the light-absorbing filaments evenly distributed within the cross-section of the hexagon. Insert white filaments into the remaining gaps to obtain a primary composite rod. Draw the primary composite rod into a primary multifilament at a scaling ratio of 0.041.

[0095] A secondary composite rod is obtained by arranging 469 primary multifilaments into a hexagon with 12 primary multifilaments on each side, and then drawing it into secondary multifilaments according to a reduction ratio of 0.049.

[0096] After the secondary multifilaments are cut to a fixed length and arranged into plate segments, they are melt-pressed into shape with a compression ratio of 0.75. After rounding, they are processed to obtain an optical fiber blank. The optical fiber blank is sliced ​​and then twisted at both ends by 180° to obtain an optical fiber image converter with a unit wire diameter of 6 micrometers.

[0097] Comparative Example 1

[0098] The difference from Example 3 is that the light-absorbing glass is made into a circular light-absorbing filament with a diameter of 0.410 mm, and the core glass is made into a circular white filament with a diameter of 0.410 mm; 90 of the aforementioned circular light-absorbing filaments are inserted into the gaps between the single filaments so that the light-absorbing filaments are evenly distributed in the hexagonal cross-section, and the remaining gaps are filled with circular white filaments.

[0099] Comparative Example 2

[0100] The difference from Example 3 is that the light-absorbing glass is made into a circular light-absorbing filament with a diameter of 0.410 mm, and the core glass is made into a circular white filament with a diameter of 0.410 mm; 128 of the aforementioned circular light-absorbing filaments are inserted into the gaps between the single filaments so that the light-absorbing filaments are evenly distributed in the hexagonal cross-section, and the remaining gaps are filled with circular white filaments.

[0101] Comparative Example 3

[0102] The difference from Example 3 is that the primary composite rod is drawn into a primary multifilament at a reduction ratio of 0.035, and the secondary composite rod is drawn into a secondary multifilament at a reduction ratio of 0.033.

[0103] Comparative Example 4

[0104] The difference from Example 3 is that the light-absorbing glass is made into circular light-absorbing filaments with a diameter of 0.410 mm, and the core glass is made into circular white filaments with a diameter of 0.410 mm. Ninety of the aforementioned circular light-absorbing filaments are inserted into the gaps between the monofilaments, ensuring that the circular light-absorbing filaments are evenly distributed within a hexagonal cross-section. The remaining gaps are filled with circular white filaments. The primary composite rod is drawn into a primary multifilament at a reduction ratio of 0.035, and the secondary composite rod is drawn into a secondary multifilament at a reduction ratio of 0.033.

[0105] The fiber optic image inverters prepared in Examples 1-5 and Comparative Examples 1-3 were subjected to contrast tests, black / white screen tests, and resolution tests, respectively. The test results are shown in Table 1.

[0106] Table 1. Test results of fiber optic image reversors prepared in Examples 1-5 and Comparative Examples 1-3.

[0107]

[0108] The contrast ratios of the fiber optic image reversers obtained in Examples 1-5 are all less than 1, indicating high contrast ratios and good anti-stray crosstalk performance. The black screen pass rate of the fiber optic image reversers obtained in Examples 1-5 is over 83%, the white screen pass rate is over 82%, the center resolution reaches a maximum of 228, and the edge resolution reaches a maximum of 161.

[0109] Compared to Example 3, Comparative Example 1 shows an increased contrast value. This is because Comparative Example 1 uses circular light-absorbing wires. Although Comparative Example 1 and Example 3 have the same number of light-absorbing wires, Example 3 uses equilateral triangular light-absorbing wires to achieve a greater degree of filling of the gaps, which is equivalent to increasing the volume of a single light-absorbing wire. Thus, fewer light-absorbing wires are needed to adjust the panel contrast.

[0110] Comparative Example 2 and Example 3 showed similar contrast values. Comparative Example 2 also used circular light-absorbing filaments, but the total amount of light-absorbing material in Comparative Example 2 was the same as in Example 3, hence the similar contrast values. However, compared to Example 3, Comparative Example 2 showed a significant decrease in the black / white mesh pass rate. This is because the number of light-absorbing filaments increased in Comparative Example 2, which affected light diffusion, resulting in a greater black / white mesh.

[0111] Compared to Example 3, Comparative Examples 1-4 showed a significant decrease in the black / white mesh pass rate and edge resolution. Specifically, in Comparative Example 4, the black mesh pass rate was only 58.7%, the white mesh pass rate was only 22.8%, and the edge resolution was only 57. This demonstrates that by inserting equilateral triangular light-absorbing filaments and equilateral triangular white filaments into the gaps between the monofilaments, and controlling the primary scaling factor to be less than the secondary scaling factor, the black / white mesh of the fiber optic image reversal can be improved, the edge resolution loss problem can be solved, and the pass rate of the finished product can be increased, making it more suitable for practical use.

[0112] The technical features in the claims and / or specification of this invention can be combined, and the combination is not limited to the combinations obtained through reference in the claims. Technical solutions obtained by combining the technical features in the claims and / or specification are also within the scope of protection of this invention.

[0113] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A method for fabricating an optical fiber image reverser, characterized in that, Includes the following steps: (1) A regular hexagon is formed by arranging monofilaments in the closest packing manner, and equilateral triangular light-absorbing filaments and equilateral triangular white filaments are inserted into the gaps between the monofilaments to obtain a primary composite rod; the monofilaments are composed of a glass core and a glass skin layer wrapped around the surface of the glass core; (2) The primary composite rod is drawn into a primary multifilament according to the primary reduction ratio; (3) Arrange the primary multifilaments into a regular hexagon using a close-packing method to obtain a secondary composite rod; draw the secondary composite rod into secondary multifilaments according to a secondary scaling ratio; and... (4) The secondary multifilament is made into an optical fiber image inverter; The first scaling factor: The second scaling factor = 0.75 to 0.95; The first scaling factor is 0.033 to 0.

036.

2. The preparation method according to claim 1, characterized in that, The material of the white filament in the equilateral triangle is the same as the material of the glass core.

3. The preparation method according to claim 1, characterized in that, The diameter of the light-absorbing filament in the equilateral triangle and the diameter of the white filament in the equilateral triangle are 0.178-0.205 times the diameter of the single filament.

4. The preparation method according to claim 1, characterized in that, The secondary scaling factor is 0.035 to 0.

04.

5. The preparation method according to claim 4, characterized in that, In step (1), the regular hexagon is composed of 217 monofilaments arranged together, with 9 monofilaments on each side; In step (3), the regular hexagon is formed by 469 primary multifilaments, with 13 primary multifilaments on each side.

6. The preparation method according to claim 1, characterized in that, The method for manufacturing the fiber optic image converter using the secondary multifilament is as follows: the secondary multifilament is cut to a fixed length and arranged into plate segments, then melt-pressed at a compression ratio of 0.75 to 0.95 and rolled into a round shape to obtain a fiber optic blank; the fiber optic blank is sliced ​​and then twisted at both ends by 180° to obtain the fiber optic image converter.

7. The preparation method according to claim 1, characterized in that, The light-absorbing glass used in the equilateral triangular light-absorbing filament is composed of the following components in molar percentage: SiO2: 71-80.0%; Al2O3: 0.5-5.0%; B2O3: 1.0-5.0%; Na2O: 1.0-11.0%; K2O: 6.0-11.0%; MgO: 0.1-2.0%; CaO: 0.1-2.0%; BaO: 0-0.04%; TiO2: 0-1.0%; Co2O3: 0.1-0.4%; NiO: 0.1-1.0%; MnO: 1.0-5.0%; V2O5: 0.1-1.0%; CeO2: 0-0.2%; and CuO: 0-0.05%.

8. A fiber optic image reversing device, characterized in that, Prepared according to the preparation method according to any one of claims 1-7.

9. An image transmission device, characterized in that, It includes the fiber optic image inverter of claim 8.

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