A fluorescent screen and a method for producing the same

Abstract

The embodiment of the present application relates to a fluorescent screen, comprising: a fluorescent screen part; a first structure layer, the first structure layer is arranged on the fluorescent screen part; the first structure layer comprises a fluorescent powder layer and a filling oxide; the fluorescent powder layer comprises fluorescent powder and bonding oxide, the bonding oxide is used for bonding together between the particles of the fluorescent powder and the surface of the fluorescent screen part; the filling oxide is inorganic material; at least part of the filling oxide is filled in the internal pore of the fluorescent powder layer.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of light-emitting devices, and in particular to a fluorescent screen. BACKGROUND

[0002] The ultraviolet light source has broad application prospects in the fields of sterilization and disinfection, surface modification, ultraviolet communication, etc. The traditional ultraviolet light source mainly includes mercury lamps, ultraviolet LEDs and ultraviolet excimer lamps. Among them, the mercury lamp contains mercury, which is easy to cause mercury pollution in the production and use process; the ultraviolet LED has low conversion efficiency and high production cost; the ultraviolet excimer lamp has short service life and high cost.

[0003] The cathode ray tube is a kind of component that realizes light emission and display by exciting fluorescent powder with electron beams, and is commonly used in display devices. Recently, research on devices using cathode ray tubes to realize ultraviolet light emission has been actively carried out; however, the cathode ray tube realizing ultraviolet light emission has great differences in structure, performance and product requirements from the traditional cathode ray tube used for display. There are still many technical problems to be solved for the ultraviolet cathode ray tube.

[0004] How to improve the luminous intensity of the light-emitting device and how to reduce pollution are important technical problems that need to be solved in the field. SUMMARY

[0005] Therefore, the embodiments of the present application provide a fluorescent screen to solve at least one problem in the background art.

[0006] To achieve the above-mentioned purpose, on one hand, the embodiments of the present application provide a fluorescent screen, which comprises:

[0007] a fluorescent screen part;

[0008] a first structure layer, which is arranged on the fluorescent screen part;

[0009] The first structure layer comprises a fluorescent powder layer and a filling oxide; the fluorescent powder layer comprises fluorescent powder and bonding oxide, and the bonding oxide is used to bond the particles of the fluorescent powder and the surface of the fluorescent screen part together;

[0010] The filling oxide is an inorganic material;

[0011] At least part of the filling oxide is filled in the internal pores of the fluorescent powder layer.

[0012] On the other hand, another embodiment of the present application further provides a preparation method of a fluorescent screen, which comprises:

[0013] providing a fluorescent screen part;

[0014] forming a fluorescent powder layer on the fluorescent screen part;

[0015] filling the phosphor layer with a filling oxide to form a first structure layer comprising the phosphor layer and the filling oxide, wherein at least part of the filling oxide fills in the internal pores of the phosphor layer.

[0016] The fluorescent screen in the embodiments of the present application fills the internal pores of the phosphor layer with a filling oxide, thereby greatly reducing the size of the internal pores of the phosphor layer. On one hand, this provides a prerequisite for forming a conductive layer directly on the phosphor layer to avoid using an organic film, so that there is no organic residue caused by using an organic film, thereby reducing the absorption of ultraviolet light. On the other hand, the reduction of the pores can effectively reduce the "blackening of phosphor" phenomenon, thereby improving the luminous intensity. Furthermore, the filling oxide filling in the internal pores of the phosphor layer can form a light guide structure composed of the filling oxide, the light generated by the phosphor layer can be transmitted and emitted through the light guide structure, effectively reducing the loss of ultraviolet light during the transmission in the internal pores, thereby enhancing the luminous intensity. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments described in the present application, and other drawings can also be obtained according to these drawings without creative labor for those skilled in the art.

[0018] Figure 1 is a schematic diagram of a cathode ray tube structure of an embodiment of the present application;

[0019] Figure 2 is a schematic diagram of a glass envelope structure of an embodiment of the present application;

[0020] Figure 3 is a schematic diagram of a glass envelope structure of an embodiment of the present application;

[0021] Figure 4 is a schematic diagram of a glass envelope structure of an embodiment of the present application;

[0022] Figure 5 is a schematic diagram of a light-emitting structure layer structure of an embodiment of the present application;

[0023] Figure 6 is a luminescence spectrum diagram of a phosphor layer of an embodiment of the present application under electron beam excitation;

[0024] Figure 7 is a luminescence spectrum diagram of different phosphor phosphor layers of an embodiment of the present application under electron beam excitation;

[0025] Figure 8is a single-layer fluorescent powder layer structure schematic diagram of an embodiment of the present application

[0026] Figure 9 is a multi-layer fluorescent powder layer structure schematic diagram of an embodiment of the present application

[0027] Figure 10 is a luminescence spectrum diagram of a fluorescent powder layer of different structures under electron beam excitation of an embodiment of the present application

[0028] Figure 11 is a preparation method flow chart of a fluorescent powder layer of an embodiment of the present application

[0029] Figure 12 is a surface SEM diagram of a fluorescent powder layer of an embodiment of the present application

[0030] Figure 13 is a preparation method flow chart of a luminescent structure layer of an embodiment of the present application

[0031] Figure 14 is a fluorescent screen structure schematic diagram of an embodiment of the present application

[0032] Figure 15 is a surface SEM diagram of a first structure layer of an embodiment of the present application

[0033] Figure 16 is a preparation method flow chart of a fluorescent screen of an embodiment of the present application

[0034] Figure 17 is an electron gun structure schematic diagram of an embodiment of the present application

[0035] Figure 18 is an electric lead assembly structure schematic diagram of an embodiment of the present application DETAILED DESCRIPTION

[0036] In order to make the person skilled in the art better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Although the exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms, and should not be limited by the specific embodiments described herein. On the contrary, these embodiments are provided so that the present application can be more thoroughly understood, and the scope of the present application disclosed can be completely conveyed to the person skilled in the art.

[0037] In the following description, numerous specific details are given to provide a thorough understanding of the embodiments. However, it will be apparent that the embodiments can be practiced without one or more of the specific details. In other instances, well-known structures and techniques have not been described in order to avoid obscuring the embodiments. Unless otherwise specifically defined herein, all terms are to be given their broadest possible interpretation including modifi cations and variants thereof.

[0038] In the drawings, the size of layers, regions, elements, and the like can be exaggerated for clarity. Like reference numerals designate like elements throughout.

[0039] It should be understood that when a certain feature is referred to as being "on" or "connected to" another feature, it can be directly on, connected to, or adjacent to the other feature, or intervening features can also be present. In contrast, when a certain feature is referred to as being "directly on" or "directly connected to" another feature, there are no intervening elements or layers present. Spatially relative terms, such as "on", "under", and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the drawings. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings. For example, if a device in the drawings is turned over, the elements described as being "below" or "beneath" other elements or features would then be oriented "above" or "over" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device can be otherwise oriented (rotated 90° or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0040] It will be understood that, although the terms first, second, third, etc. can be used herein to describe various features / elements, these features / elements should not be limited by these terms. These terms are only used to distinguish one feature / element from another. Thus, a first feature / element discussed below could be termed a second feature / element without departing from the teachings of the present application. The singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. It will be further understood that the terms "comprises" and / or "comprising", when used in this specification, specify the presence of stated features, steps, and / or elements, but do not preclude the presence or addition of one or more other features, steps, and / or elements. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0041] As shown in FIG. 1, the ultraviolet cathode-ray tube 10 according to an embodiment of the present application includes a glass envelope 20 and an electron gun 30. The glass envelope 20 includes a faceplate portion 21 and a tubular portion 22 connected to the faceplate portion 21, and the electron gun 30 is disposed in the tubular portion 22 and is configured to emit electron beams toward the faceplate portion 21. Figure 1

[0042] ​For the purpose of clearly illustrating the technical solutions of the present application, the following terms are defined as follows Figures 1-4 The axis A is the central axis of the fluorescent screen portion 21. The extending direction of the axis A is referred to as the longitudinal direction. It can be understood that the extending direction of the axis A is perpendicular to the surface of the fluorescent screen portion 21. The fluorescent screen portion 21 is connected to one end of the tubular portion 22. The fluorescent screen portion 21 has an inner surface facing the tubular portion 22 and an outer surface away from the tubular portion 22, and both the inner surface and the outer surface of the fluorescent screen portion 21 are perpendicular to the axis A.

[0043] Optionally, the fluorescent screen portion 21 is made of one or more inorganic light-transmitting materials, and the ultraviolet light transmittance of the inorganic light-transmitting material in the wavelength range of 190 nm-250 nm is greater than or equal to 80%. Optionally, the inorganic light-transmitting material can be one of quartz glass, sapphire crystal or magnesium fluoride crystal. Further, the inorganic light-transmitting material is quartz glass or sapphire crystal. The quartz glass or sapphire crystal has the advantages of lead-free and high purity compared with ordinary electronic glass, thereby reducing pollution, reducing impurity absorption of ultraviolet light, and improving the ultraviolet light emission efficiency of the cathode ray tube.

[0044] Optionally, the material of the tubular portion 22 and the material of the fluorescent screen portion 21 are both quartz glass or sapphire crystal. In this way, the connection between the two is a matching seal, and there is almost no stress problem at the sealing position. The glass envelope has the advantages of good sealing effect, scalable sealing process, low cost, good shock resistance, good explosion-proof performance, etc. It should be noted that the matching seal in the embodiment of the present application means that the two sealing materials have similar or identical coefficients of thermal expansion, and the shrinkage of the two materials can be consistent during the gradual cooling process after high-temperature sealing, thereby eliminating the internal stress caused by the shrinkage difference.

[0045] As a feasible implementation manner, the fluorescent screen portion 21 and the tubular portion 22 are formed separately, and then sealed and cooled after high-temperature melting. Since the materials are the same, the softening temperature and the coefficient of thermal expansion of the fluorescent screen portion 21 and the tubular portion 22 are basically consistent, so it is easy to seal and form a glass envelope 20 with stable performance. As another feasible implementation manner, the fluorescent screen portion 21 and the tubular portion 22 are formed in a one-time melting molding process. Specifically, the raw material is melted to a plastic state, and then the molten raw material is shaped and cooled according to the shape and size requirements of the glass envelope 20, so as to obtain the glass envelope 20 including the fluorescent screen portion 21 and the tubular portion 22. In this way, not only the production efficiency of the glass envelope 20 can be improved, but also the internal stress can be further reduced due to the absence of the sealing process. The glass envelope 20 has high shock resistance and stability.

[0046] Optionally, the fluorescent screen part 21 is in a shape of a circular plate, and the inner surface of the fluorescent screen part 21 is in a shape of a circle. Optionally, the tubular part 22 is in a shape of a circular tube, and the inner diameter of the tubular part 22 is less than or equal to the diameter of the inner surface of the fluorescent screen part 21. Compared with the inner surface of the fluorescent screen part 21 in a general square or other shape, the circular inner surface can receive more electron beam bombardment in the same area, so as to improve the luminous intensity of the ultraviolet light. Moreover, if the implementation mode of separately forming the fluorescent screen part 21 and the tubular part 22 and then sealing is adopted, the side surface of the circular plate-shaped fluorescent screen part 21 is smooth, and the sealing at different positions is easier to control uniformly, so as to reduce the stress caused by the inconsistent thickness of the sealing position. Optionally, the thickness of the fluorescent screen part 21 is between 0.5 mm and 3 mm. Optionally, the thickness of the tube wall of the tubular part 22 is between 0.5 mm and 2 mm.

[0047] As shown in Figures 2-4 , the bulb 20 includes the tubular part 22 and the fluorescent screen part 21. The tubular part 22 includes the first cylinder part 220, and the inner surface of the first cylinder part 220 is perpendicular to the inner surface of the fluorescent screen part 21. Optionally, the first cylinder part 220 can be directly connected with the fluorescent screen part 21 (as shown in Figure 2 ), or can not be directly connected. In the case of not being directly connected, the tubular part 22 can further include the taper part 221, and the first cylinder part 220 is connected with the fluorescent screen part 21 through the taper part 221. Further, the taper part 221 is connected with the fluorescent screen part 21 through the second cylinder part 202. As shown in Figures 2-4 , three optional embodiments of the bulb 20 are shown.

[0048] As shown in Figure 2 , as an optional embodiment of the bulb 20, the tubular part 22 includes the first cylinder part 220, and one end of the first cylinder part 220 is connected with the fluorescent screen part 21. Optionally, the inner surface of the first cylinder part 220 is perpendicular to the inner surface of the fluorescent screen part 21, that is, the first cylinder part 220 and the fluorescent screen part 21 form a bottom-closed cylinder. In this way, on the one hand, the amount of solution above each area position on the inner surface of the fluorescent screen can be kept consistent during the deposition of the fluorescent powder, so that the fluorescent powder is more uniformly deposited on the inner surface of the fluorescent screen part 21, and on the other hand, the side wall of the cylinder part is easier to control the thickness in the processing process, so as to more easily achieve the consistent thickness, and the anti-shock and explosion-proof performance is better.

[0049] As shown in Figure 3As shown, as another alternative embodiment of the bulb 20, the tubular portion 22 comprises a tapered portion 221 and a first cylinder portion 220. The tapered portion 221 comprises a small opening end close to the first cylinder portion 220 and a large opening end away from the first cylinder portion 220; the large opening end of the tapered portion 221 is connected to the screen portion 21, and the small opening end of the tapered portion 221 is connected to the first cylinder portion 220. The electron gun 30 is arranged in the tubular portion 22, specifically in the first cylinder portion 220. Alternatively, the ratio of the distance from the end face of the small opening end of the tapered portion 221 to the inner surface of the screen portion 21 to the diameter of the inner surface of the screen portion 21 is between 1:0.5 and 1:4, so as to facilitate the control of the electron beam angle and make the electron beam uniformly emitted onto the entire inner surface of the screen portion 21.

[0050] As Figure 4As shown, as another alternative embodiment of the bulb 20, the tubular part 22 comprises a first cylinder part 220, a taper part 221 and a second cylinder part 222, the inner diameter of the second cylinder part 222 is larger than that of the first cylinder part 220. The taper part 221 comprises a small opening end close to the first cylinder part 220 and a large opening end away from the first cylinder part 220; one end of the second cylinder part 222 is connected with the large opening end of the taper part 221, the other end of the second cylinder part 222 is connected with the screen part 21, and the small opening end of the taper part 221 is connected with the first cylinder part 220. It is to be noted that the end face of the small opening end of the taper part 221, the end face of the large opening end of the taper part 221 and the inner surface of the screen part 21 are parallel to each other. Alternatively, the inner surface of the second cylinder part 222 is perpendicular to the inner surface of the screen part 21, i.e. the second cylinder part 222 and the screen part 21 form a bottom-closed cylinder. The electron gun 30 is arranged in the tubular part 22, specifically in the first cylinder part 220. By arranging the inner surface of the second cylinder part 222 to be perpendicular to the inner surface of the screen part 21, the amount of solution above the inner surface of the screen part 21 is the same in the gravity precipitation method, and the fluorescent powder can uniformly precipitate on the inner surface of the screen part under the action of gravity, i.e. the thickness of the fluorescent powder at each position of the inner surface of the screen part is more uniform, thereby improving the light-emitting effect. Alternatively, the height of the second cylinder part 222 is greater than or equal to 20 mm, so that the fluorescent powder can be more uniformly distributed at the bottom of the bulb 20, thereby improving the uniformity of the fluorescent powder layer. It can be understood that the height of the second cylinder part 222 refers to the length of the second cylinder part 222 in the direction of the axis "A". Alternatively, the ratio of the distance from the end face of the small opening end of the taper part 221 to the inner surface of the screen part 21 to the diameter of the inner surface of the screen part 21 is between 1:0.5 and 1:4, so as to facilitate the control of the electron beam angle to uniformly emit the electron beam to the entire inner surface of the screen part 21, otherwise, too small or too large electron beam angle is not conducive to uniformly emitting the electron beam to the entire inner surface of the screen part 21. Alternatively, the ratio of the distance from the end face of the small opening end of the taper part 221 to the end face of the large opening end of the taper part 221 to the height of the second cylinder part 222 is between 0.5:1 and 2:1, so as to more easily control the electron beam to emit to the entire inner surface of the screen part 21, avoiding the electron beam being blocked by the inner surface of the taper part 221.

[0051] It can be understood that the taper part 221 in the embodiment is not limited to Figure 3 or Figure 4 the case that the side wall between the small opening end and the large opening end extends in a straight line with an unchanged slope, the taper part 221 can also include a side wall with a varying slope, or even include multiple sub-taper parts, and each sub-taper part can be connected by other cylinder parts, which will not be described here.

[0052] Understandably, the cross-sectional dimensions of the cone 221 in the direction perpendicular to axis "A" gradually increase or decrease; while the cross-sectional dimensions of the cylinder in the direction perpendicular to axis "A" remain unchanged.

[0053] Optional, such as Figures 2-4 As shown, the glass shell 20 also includes a sealing portion 23, which is connected to the end of the tubular portion 22 away from the fluorescent screen portion 21. The sealing portion 23 is configured to seal the port of the tubular portion 22 away from the fluorescent screen portion 21. The glass shell 20, through the fluorescent screen portion 21, the tubular portion 22, and the sealing portion 23, forms a sealed internal space, and the internal space of the glass shell 20 is in a vacuum state. Specifically, the air pressure in the internal space of the glass shell 20 can be 10... -2 ~10 -7 The pressure difference between Pa and the internal space can reduce the impact of residual air on the electron beam and cathode. Optionally, the thickness of the sealing part 23 is greater than the wall thickness of the tubular part 22 and less than the inner diameter of the tubular part 22. Optionally, the material of the sealing part 23 is quartz glass or sapphire crystal. In existing ultraviolet light sources, mercury lamps and excimer ultraviolet lamps are both gas discharge lamps. The internal gas pressure of a gas discharge lamp is 5-10 times the external atmospheric pressure. In the embodiment of this application, the external atmospheric pressure is 10 times the internal gas pressure of the glass shell. 7 -10 12Therefore, compared with the gas discharge lamp, the sealing and air-tightness requirements of the envelope of the embodiment of the application are much higher, the material of the screen part, the material of the closed part and the material of the tubular part are all quartz glass or sapphire crystal, so that a matched sealing can be formed and the air-tightness requirement of the envelope can be met. Alternatively, the closed part 23 is formed by deforming one end of the tubular part 22, and specifically, the open end of the tubular part 22 is pressed in a high-temperature molten state and then cooled to form the closed part 23. The maximum cross section of the sealing part is parallel to the axis "A". In a specific application, the closed part 23 is flat, and the length of the flat sealing part is greater than 15 mm. It can be understood that the flat closed part 23 specifically means that the length and the width of the closed part 23 are both obviously greater than the thickness of the closed part 23, for example, the length of the closed part 23 is greater than 15 mm, the width is greater than 10 mm, and the thickness is less than 4 mm. It should be noted that in the process of deforming one end of the tubular part 22 into the closed part 23, a transition part 24 is also formed between the tubular part 22 and the closed part 23. One end of the transition part 24 is connected to the tubular part 22, and the other end is connected to the closed part 23. The transition part 24 specifically refers to the part where the opening of the tubular part 22 is gradually closed but not completely closed after being pressed and deformed. Compared with the traditional sealing method, the closed part 23 provided by the embodiment of the application has a better sealing effect. On the one hand, the material of the closed part and the material of the tubular part are both quartz glass or sapphire crystal, so that a matched sealing can be formed, the sealing effect is good, and the air-tightness requirement of the envelope can be met. On the other hand, the closed part formed by directly deforming the open end of the tubular part can form a smooth connection in the high-temperature heating sealing process, the sealing is convenient and simple, and has a better connection effect.

[0054] Alternatively, as shown in Figures 2-4 The envelope 20 also includes an exhaust part 25. Specifically, the exhaust part 25 is arranged on the tubular part 22, one end of the exhaust part 25 is connected to the inside of the tube, and the other end is sealed. Alternatively, the material of the exhaust part 25 is the same as the material of the tubular part 22. In a specific application, the side wall of the tubular part 22 is locally heated to a molten state at a high temperature, and then one end of the exhaust pipe with two open ends is inserted into the side wall heated to a molten state at a high temperature. After cooling, the exhaust pipe is fixed on the tubular part 22. When exhaust operation is required, the other end of the exhaust pipe is connected to the air exhaust equipment and the exhaust operation is performed. When the vacuum degree in the tube reaches a preset value, the other end of the exhaust pipe is heated to a molten state and then pressed and sealed. After cooling, the exhaust part 25 is formed. Alternatively, the exhaust part 25 is arranged on the tubular part 22 close to the electron gun 30, that is, the distance between the exhaust part 25 and the electron gun 30 is less than the distance between the exhaust part 25 and the fluorescent part. Specifically, in the embodiment in which the tubular part 22 includes the tapered part 221, the exhaust part 25 is arranged on the first cylindrical part 220, and the inner and outer surfaces of the first cylindrical part 220 are not coated with other materials, which makes it more convenient to arrange the exhaust part.

[0055] Optionally, the ultraviolet cathode-ray tube 10 further comprises an anode metal rod (not shown in the figure). The anode metal rod penetrates the tubular part 22, and specifically, one end of the anode metal rod is arranged in the tubular part 22 and connected with the conductive layer of the inner wall of the tubular part 22, and the other end of the anode metal rod is arranged on the tubular part 22 and connected with an external high voltage, so that the inner wall of the tubular part 22 forms a high-voltage electric field. Optionally, the middle part of the anode metal rod is connected with the tubular part 22 by fusion. Specifically, the surface of the anode metal rod is plated with a transition metal film, wherein the thermal expansion coefficient of the transition metal film is between the glass bulb 20 and the anode metal rod; the anode metal rod is a tungsten rod, and the transition metal film can be a nickel film. Through the transition metal film, the problem of internal stress caused by the mismatch of the thermal expansion coefficient is reduced, and the sealing effect is improved. Optionally, the anode metal rod is arranged on the tubular part 22 close to one side of the screen part 21.

[0056] As shown in Figure 1 The ultraviolet cathode-ray tube 10 in the embodiment of the present application further comprises a light-emitting structure layer 40, which is arranged on the screen part 21, and the light-emitting structure layer 40 emits ultraviolet light under the excitation of an electron beam.

[0057] As shown in Figure 5 The light-emitting structure layer 40 comprises a fluorescent powder layer 41, which is arranged on the screen part 21. The electron gun 30 is used to emit an electron beam to the screen part 21, and specifically, is used to emit all or most of the electron beam to the fluorescent powder layer 41, and the fluorescent powder layer 41 emits ultraviolet light under the excitation of the electron beam.

[0058] In a specific application, the fluorescent powder layer 41 is arranged on the inner surface of the screen part 21. Here, the inner surface refers to the surface of the screen part 21 close to the electron gun 30. Optionally, the thickness of the fluorescent powder layer 41 is between 5-50 μm. Here, the thickness of the fluorescent powder layer 41 is the distance between the inner surface of the screen part 21 and the surface of the fluorescent powder layer 41, wherein the surface of the fluorescent powder layer 41 refers to the surface of the fluorescent powder layer 41 on the side facing the electron gun 30.

[0059] Optionally, the main emission peak of the ultraviolet light emitted by the phosphor layer 41 under electron beam excitation has a wavelength between 190 nm and 250 nm. It should be noted that the main emission peak in the embodiments of the present application refers to the emission peak with the maximum luminous intensity under electron beam excitation. As can be easily understood, if the emitted ultraviolet light also includes other emission peaks, the luminous intensity of any other emission peak is less than that of the main emission peak. It should be noted that the wavelengths of different emission peaks are at least 5 nm apart. If the wavelengths of different emission peaks are within 5 nm, they are considered as the same emission peak. The shorter the wavelength of the ultraviolet light, the stronger the energy and the weaker the penetration. For example, in the field of sterilization and disinfection, the shorter the wavelength of the ultraviolet light, the higher the energy, which can not only effectively destroy the DNA of virus or bacterial cells, but also reduce the harm to human skin due to the weak penetration. Therefore, the ultraviolet light with a shorter wavelength has a broader application prospect. The ultraviolet cathode ray tube 10 in the embodiments of the present application emits ultraviolet light by exciting the phosphor layer 41 with an electron beam. The main emission peak of the emitted ultraviolet light has a wavelength between 190 nm and 250 nm. Compared with the mercury lamp and the ultraviolet LED lamp with a wavelength of 254 nm, the ultraviolet light emitted by the embodiments of the present application has a smaller wavelength, a higher luminous energy, an adjustable luminous intensity, and an adjustable luminous frequency, and has a broader application prospect in the fields of sterilization and disinfection, ultraviolet communication, and ultraviolet curing.

[0060] Optionally, the emitted ultraviolet light also includes at least one secondary emission peak in the range of a wavelength less than or equal to 300 nm, and the ratio of the luminous intensity of the secondary emission peak to the luminous intensity of the main emission peak is greater than or equal to 1:10. For example, the ultraviolet light emitted by the phosphor layer containing LaPO4:Pr phosphor under electron beam excitation includes a main emission peak and a secondary emission peak, wherein the wavelength of the main emission peak is 225 nm, and the wavelength of the secondary emission peak is 280 nm.

[0061] Optionally, the emitted ultraviolet light also includes more than two secondary emission peaks in the range of a wavelength less than or equal to 300 nm, and the ratio of the luminous intensity of the secondary emission peak to the luminous intensity of the main emission peak is greater than or equal to 1:10. For example, as shown in FIG. 3, the ultraviolet light emitted by the phosphor layer containing YPO4:Pr phosphor under electron beam excitation includes a main emission peak and three secondary emission peaks, wherein the wavelength of the main emission peak is 232 nm, the wavelength of the first secondary emission peak is 243 nm, the wavelength of the second secondary emission peak is 261 nm, and the wavelength of the third secondary emission peak is 271 nm. Figure 6 As shown in FIG. 3, it is a luminous spectrum diagram of the phosphor layer in an embodiment of the present application under electron beam excitation. The ultraviolet light emitted by the phosphor layer containing YPO4:Pr phosphor includes a main emission peak and three secondary emission peaks, wherein the wavelength of the main emission peak is 232 nm, the wavelength of the first secondary emission peak is 243 nm, the wavelength of the second secondary emission peak is 261 nm, and the wavelength of the third secondary emission peak is 271 nm.

[0062] Optionally, the fluorescent powder layer 41 emits ultraviolet light under electron beam excitation, and the cumulative emission intensity of the ultraviolet light at a wavelength of 190nm-250nm is greater than the cumulative emission intensity at a wavelength of 250nm-300nm. The cumulative emission intensity refers to the sum of the cumulative intensity at a certain wavelength range, which is expressed by the formula G = ∫f(x)dx, wherein G represents the cumulative emission intensity, x represents the wavelength, and f(x) represents the emission intensity at the wavelength x.

[0063] As shown in FIG. 1, the fluorescent powder layer 41 in the embodiment of the present application can include fluorescent powder 410, and the fluorescent powder layer 41 emits ultraviolet light under electron beam excitation, specifically the fluorescent powder 410 emits ultraviolet light under electron beam excitation. Figure 5

[0064] Optionally, the fluorescent powder includes a matrix material and a doping element, wherein the doping element is incorporated into the matrix material to form impurity defects to cause light emission. Optionally, the doping element contains Nd, Pr or Bi, and the elements Nd, Pr or Bi can emit ultraviolet light less than 250nm after absorbing electron beam energy, while having the advantages of high light emission efficiency and short light emission wavelength. Optionally, the matrix material is a rare earth phosphate, which has the advantages of low phonon energy and stable properties, and as a matrix material, it can withstand electron beam bombardment, which can significantly improve the light emission intensity and service life of the fluorescent powder layer.

[0065] As an optional implementation, the fluorescent powder contains a doping element, and the doping element contains at least one selected from Nd, Pr and Bi, and the doping element emits ultraviolet light after being excited by an electron beam. Optionally, as the doping element, Nd, Pr and Bi mainly have stable trivalent electron configuration. Further, the fluorescent powder can include at least one of the following: RePO4:Z1, LaP5O 14 :Z1, CaSO4:Z1, SrSO4:Z1, NaYF4:Z1, LiYF4:Z1, KYF4:Z1, LiLaP4O 12 :Z1, Y2(SO4)3:Z1, YAlO3:Z1, YF3:Z1; wherein Re represents one or more selected from Y, La, Lu, Sr, Gd, Sm and Ce, Z1 represents a doping element, and the doping element contains one element selected from Nd, Pr and Bi. Optionally, the molar ratio of the doping element to the matrix material doped with the doping element is less than 5:95, i.e., the doping element concentration is less than or equal to 5%. As Figure 6 ​As shown, the main emission peak wavelength of the ultraviolet light emitted by the fluorescent powder layer containing YPO4:Nd fluorescent powder (the doping concentration of Nd is 1%, i.e. the molar ratio of Y and Nd is 99:1) is 195 nm, the first emission peak wavelength is 277 nm, and the second emission peak wavelength is 240 nm; the intensity integral area of the luminescence spectrum curve in the wavelength range of 190 nm-250 nm is 14.3, the intensity integral area of the luminescence spectrum curve in the wavelength range of 250 nm-300 nm is 8.9, and the cumulative emission intensity of the emitted ultraviolet light in the wavelength range of 190 nm-250 nm is greater than the cumulative emission intensity in the wavelength range of 250 nm-300 nm. Table 1 shows the main emission peak wavelength in the cathode ray emission spectrum of the fluorescent powder in the embodiment of the present application, and the doping element concentration of the fluorescent powder in the table is 1% and the electron beam acceleration voltage is 10 kV. It should be understood that the wavelength of the main emission peak in the cathode ray luminescence spectrum of the fluorescent powder is affected by the particle size, doping concentration and electron beam acceleration voltage of the fluorescent powder, and the main emission peak wavelength may be different under different conditions; at the same time, the fluorescent powder in the embodiment of the present application is a fluorescent powder excited by an electron beam, which is completely different from a photoluminescence fluorescent powder; even if the same fluorescent powder, the spectrum curve under electron beam excitation and light excitation is not exactly the same.

[0066] Serial Number Phosphor Dominant Emission Peak Wavelength (nm) 1 LiYF4:Pr 218 2 [KYF4:Pr] 235 3 YPO4:Pr 232 4 LaPO4:Pr 225 5 [YAlO3:Pr] 245 6 YPO4:Bi 241 7 YPO4:Nd 195 8 LuPO4:Pr 235 9 LaPO4:Bi 234 10 LaPO4:Nd 192

[0067] Table 1

[0068] As another optional embodiment, the fluorescent powder contains a doping element, and the doping element is selected from at least two doping elements of Nd, Pr and Bi, which emits ultraviolet light after being excited by an electron beam; among the doping elements, Nd, Pr and Bi mainly have stable trivalent electron configurations, and Nd, Pr and Bi can form energy transfer among each other under electron beam excitation, thereby improving the luminescence intensity of the ultraviolet light. Further, the fluorescent powder can include at least one of RePO4:Z2, LaP5O 14 :Z2, CaSO4:Z2, SrSO4:Z2, NaYF4:Z2, LiYF4:Z2, KYF4:Z2, LiLaP4O 12 :Z2, Y2(SO4)3:Z2, YAlO3:Z2, YF3:Z2; wherein Re represents one or more selected from Y, La, Lu, Sr, Gd, Sm and Ce, and Z2 represents a doping element containing two elements selected from Nd, Pr and Bi. Optionally, the molar ratio of the doping element to the doped element is less than 5:95. For example, Figure 7The luminescence spectrum of the fluorescent powder layer containing YPO4:Nd (Nd doping concentration is 1%), YPO4:Bi (Bi doping concentration is 1%) and YPO4:Nd, Bi (Nd doping concentration is 1%, Bi doping concentration is 1%) under the excitation of electron beam is shown in the figure, wherein the main emission peak wavelength of the fluorescent powder layer containing YPO4:Nd is 195 nm, the first emission peak wavelength is 277 nm, and the second emission peak wavelength is 240 nm; the main emission peak wavelength of the fluorescent powder layer containing YPO4:Bi is 241 nm; the main emission peak wavelength of the fluorescent powder layer containing YPO4:Nd, Bi is 241 nm, the first emission peak wavelength is 195 nm, and the second emission peak wavelength is 277 nm. As can be seen from the figure, the luminescence intensity of the fluorescent powder layer containing YPO4:Nd, Bi at 195 nm and 277 nm is less than that of YPO4:Nd, while the luminescence intensity at 241 nm is greater than that of YPO4:Bi; this is because in the fluorescent powder layer containing YPO4:Nd, Bi, energy transfer occurs between the doping element Nd and the doping element Bi, that is, a part of the electronic energy absorbed by Nd is transferred to Bi, which not only improves the luminescence intensity of Bi at 241 nm, but also improves the overall ultraviolet light emission intensity of the fluorescent powder layer in the range less than 300 nm. As can be clearly seen from the figure, the cumulative emission intensity of the ultraviolet light emitted by the three kinds of fluorescent powder layers in the range of 190 nm-250 nm is greater than that in the range of 250 nm-300 nm.

[0069] The fluorescent powder layer of the embodiment of the present application can be a single-layer fluorescent powder layer or a multi-layer fluorescent powder layer.

[0070] As an optional embodiment, the fluorescent powder layer is a single-layer fluorescent powder layer.

[0071] Optionally, the single layer of phosphor can include one kind of phosphor, or more than two kinds of phosphor. The single layer of phosphor can include more than two kinds of phosphor, so that the ultraviolet light with different wavelengths can be obtained by the ultraviolet light emitted by different phosphor, so as to meet the needs of different fields. For example, in the field of sterilization and disinfection, the ultraviolet light with different wavelengths can effectively kill various bacteria or viruses, so as to improve the effect of sterilization or disinfection. Further, the two kinds of phosphor included in the single layer of phosphor can be YPO4:Nd and YPO4:Pr, or YPO4:Nd and LaPO4:Pr, or YPO4:Pr and LaPO4:Pr. The YPO4:Nd phosphor, the YPO4:Pr phosphor and the LaPO4:Pr phosphor all emit ultraviolet light with multiple emission peaks under the excitation of the electron beam. The single layer of phosphor includes two of them, so that more wavelengths of ultraviolet light can be emitted at the same time, so as to meet the needs of the field of sterilization and disinfection, for example.

[0072] In a specific application, the single layer of phosphor can include more than two kinds of phosphor mixed together. Specifically, the two or more kinds of phosphor are mixed together directly, and then the single layer of phosphor is formed by the gravity sedimentation method.

[0073] In another specific application, the single layer of phosphor can include two or more sub-regional layers of phosphor. Optionally, the main emission peak wavelength of the ultraviolet light emitted by each sub-regional layer of phosphor under the excitation of the electron beam is different, and the main emission peak wavelength of the ultraviolet light emitted by at least one sub-regional layer of phosphor is between 190 nm and 250 nm. Optionally, the sub-regional layers of phosphor contain different kinds of phosphor. The different kinds of phosphor refer to that at least one kind of phosphor is different between the sub-regional layers of phosphor. It can be understood that although the single layer of phosphor includes two or more sub-regional layers of phosphor, the sub-regional layers of phosphor are located in the same layer, the lower surfaces of the sub-regional layers of phosphor are substantially coplanar, and the upper surfaces can also be substantially coplanar. The sub-regional layers of phosphor together form a single layer of phosphor. Specifically, as shown in FIG. 6, the single layer of phosphor 600 includes two sub-regional layers of phosphor 610 and 620. The lower surface of the sub-regional layer of phosphor 610 is substantially coplanar with the lower surface of the sub-regional layer of phosphor 620, and the upper surface of the sub-regional layer of phosphor 610 is substantially coplanar with the upper surface of the sub-regional layer of phosphor 620. The sub-regional layer of phosphor 610 and the sub-regional layer of phosphor 620 together form a single layer of phosphor 600. Figure 8Fig. 1 shows a schematic diagram of a single-layer phosphor layer structure according to an embodiment of the present application. The phosphor layer 41 comprises at least a first sub-region phosphor layer 412 and a second sub-region phosphor layer 413, which are arranged on different regions of the inner surface of the screen portion 21. The first sub-region phosphor layer 412 emits first ultraviolet light under electron beam excitation, and the second sub-region phosphor layer 413 emits second ultraviolet light under electron beam excitation. The main emission peak wavelength of the first ultraviolet light is different from that of the second ultraviolet light, and at least one of the main emission peak wavelengths is between 190 nm and 250 nm. Further, the phosphor of the first sub-region phosphor layer 412 and the phosphor of the second sub-region phosphor layer 413 are different in type. It can be understood that different types of phosphor means that at least one type of phosphor is different between the sub-region phosphor layers. For example, the first sub-region phosphor layer comprises phosphor LuPO4:Bi, and the second sub-region phosphor layer comprises phosphor LuPO4:Pr; or the first sub-region phosphor layer comprises phosphor LuPO4:Bi and phosphor LuPO4:Pr, and the second sub-region phosphor layer comprises phosphor LuPO4:Bi and phosphor LuPO4:Nd; or the first sub-region phosphor layer comprises phosphor LuPO4:Bi, and the second sub-region phosphor layer comprises phosphor LuPO4:Bi and phosphor LuPO4:Nd. Further, each sub-region phosphor layer can comprise one type of phosphor, or two or more types of mixed phosphor. According to the embodiment of the present application, the phosphor layer is arranged on different regions, so that multiple ultraviolet lights of different wavelengths can be generated, and the multiple ultraviolet lights can be superimposed on each other, reducing the mutual absorption between different phosphors, and thus improving the overall luminous intensity of the ultraviolet cathode-ray tube.

[0074] As another alternative embodiment, the phosphor layer comprises two or more layers of phosphor layers stacked together. Each layer of the phosphor layers can comprise one type of phosphor, or two or more types of mixed phosphor. The types of phosphor included in each layer of the phosphor layers are different. It can be understood that different types of phosphor means that at least one type of phosphor is different between the layers of the phosphor layers. The main emission peak wavelength of the ultraviolet light emitted by each layer of the phosphor layers under electron beam excitation is different, and the wavelength of each main emission peak is below 300 nm; further, at least one of the wavelengths of the main emission peaks is between 190 nm and 250 nm. Specifically, as shown in Fig. 2, the phosphor layer 41 comprises a first layer of phosphor layer 411, a second layer of phosphor layer 412, and a third layer of phosphor layer 413. The first layer of phosphor layer 411 emits first ultraviolet light under electron beam excitation, the second layer of phosphor layer 412 emits second ultraviolet light under electron beam excitation, and the third layer of phosphor layer 413 emits third ultraviolet light under electron beam excitation. The main emission peak wavelength of the first ultraviolet light is different from that of the second ultraviolet light, and the main emission peak wavelength of the second ultraviolet light is different from that of the third ultraviolet light. At least one of the main emission peak wavelengths is between 190 nm and 250 nm. Further, the types of phosphor included in the first layer of the phosphor layer 411, the second layer of the phosphor layer 412, and the third layer of the phosphor layer 413 are different. It can be understood that different types of phosphor means that at least one type of phosphor is different between the layers of the phosphor layers. For example, the first layer of the phosphor layer 411 comprises phosphor LuPO4:Bi, the second layer of the phosphor layer 412 comprises phosphor LuPO4:Pr, and the third layer of the phosphor layer 413 comprises phosphor LuPO4:Nd. Further, each layer of the phosphor layers can comprise one type of phosphor, or two or more types of mixed phosphor. Figure 9As shown in the figure is a multi-layer phosphor layer according to an embodiment of the present application. The phosphor layer 41 includes a first layer of phosphor 414 and a second layer of phosphor 415. The first layer of phosphor 414 is disposed on the inner surface of the screen portion 21, and the second layer of phosphor 415 is disposed on the first layer of phosphor 414. Further, the first layer of phosphor 414 has a main emission peak wavelength greater than that of the second layer of phosphor 415. Thus, the first layer of phosphor 414 can partially absorb the ultraviolet light emitted by the second layer of phosphor 415, thereby increasing the luminous intensity of the first layer of phosphor 414. By disposing two or more layers of phosphor, the mutual absorption of the emitted ultraviolet light between the layers of phosphor can be effectively adjusted, and not only can a variety of different wavelengths of ultraviolet light be obtained, but the intensity of each wavelength of light can also be adjusted.

[0075] As shown in the figure is a multi-layer phosphor layer according to an embodiment of the present application. The phosphor layer 41 includes a first layer of phosphor 414 and a second layer of phosphor 415. The first layer of phosphor 414 is disposed on the inner surface of the screen portion 21, and the second layer of phosphor 415 is disposed on the first layer of phosphor 414. Further, the first layer of phosphor 414 has a main emission peak wavelength greater than that of the second layer of phosphor 415. Thus, the first layer of phosphor 414 can partially absorb the ultraviolet light emitted by the second layer of phosphor 415, thereby increasing the luminous intensity of the first layer of phosphor 414. By disposing two or more layers of phosphor, the mutual absorption of the emitted ultraviolet light between the layers of phosphor can be effectively adjusted, and not only can a variety of different wavelengths of ultraviolet light be obtained, but the intensity of each wavelength of light can also be adjusted. Figure 10 As shown in the figure is a multi-layer phosphor layer according to an embodiment of the present application. The phosphor layer 41 includes a first layer of phosphor 414 and a second layer of phosphor 415. The first layer of phosphor 414 is disposed on the inner surface of the screen portion 21, and the second layer of phosphor 415 is disposed on the first layer of phosphor 414. Further, the first layer of phosphor 414 has a main emission peak wavelength greater than that of the second layer of phosphor 415. Thus, the first layer of phosphor 414 can partially absorb the ultraviolet light emitted by the second layer of phosphor 415, thereby increasing the luminous intensity of the first layer of phosphor 414. By disposing two or more layers of phosphor, the mutual absorption of the emitted ultraviolet light between the layers of phosphor can be effectively adjusted, and not only can a variety of different wavelengths of ultraviolet light be obtained, but the intensity of each wavelength of light can also be adjusted.

[0076] Optionally, the average particle size of the phosphor 410 is between 1 μm and 10 μm. If the average particle size of the phosphor is less than 1 μm, the surface defects are too many to affect the light emission. If the average particle size of the phosphor is greater than 10 μm, it is difficult to be bonded and easy to fall off. The average particle size of the phosphor between 1 μm and 10 μm can maintain the light emission efficiency and better bonding and prevent falling off.

[0077] As shown in FIG. 4, the phosphor layer 41 can further include a bonding oxide 411. Further, the phosphor layer 41 can include the bonding oxide 411 made of an inorganic material, and the bonding oxide 411 is composed of inorganic particles. The inorganic material has a small absorption of ultraviolet light, and in particular, the absorption of ultraviolet light with a wavelength less than 250 nm can be reduced. Optionally, the ratio of the average particle size of the bonding oxide 411 to the average particle size of the phosphor 410 is between 1:1000 and 1:100. The particles of the bonding oxide 411 are distributed around the particles of the phosphor 410 to bond the particles of the phosphor 410 together and bond the particles of the phosphor 410 and the inner surface of the fluorescent screen portion 21 together. Figure 5 Optionally, the particles of the bonding oxide 411 are nanoparticles with an average particle size between 1 nm and 100 nm. Specifically, at least some of the particles of the bonding oxide 411 are adsorbed on the surface of the particles of the phosphor 410. The bonding oxide 411 of the present application is nanoparticles, and the particle size of the particles of the bonding oxide 411 is much smaller than the particle size of the particles of the phosphor 410. Under the effect of the nanometer effect, the nanoparticles of the bonding oxide 411 are adsorbed on the surface of the particles of the phosphor 410 and the surface of the fluorescent screen portion 21. At the same time, the surface of the nanoparticles has many active hydroxyl groups, and the nanoparticles are easily bonded together through the active hydroxyl groups, thereby bonding the particles of the phosphor 410 together and bonding the particles of the phosphor 410 and the surface of the fluorescent screen portion 21 together.

[0078] Optionally, the mass ratio of the bonding oxide 411 to the phosphor 410 is less than 1:10, thereby reducing the problem of decreased adhesion caused by excessive agglomeration of the bonding oxide.

[0079]

[0080] ​Optionally, the main component of the bonding oxide 411 has a weight percentage greater than 99.9%, and other impurity components have a weight percentage less than 0.1%. The main component of the bonding oxide 411 refers to the component with the highest proportion in the bonding oxide 411, which is also the component that plays a bonding role in the bonding oxide 411. Specifically, the main component refers to the oxide in the bonding oxide 411, and specifically refers to one kind of oxide; the other impurity components refer to the impurity components generated in the preparation process of the main component of the bonding oxide. The bonding oxide 411 only contains inorganic components, and does not contain organic components and organic residual components. It should be noted that the organic component in the embodiment of the present application refers to a compound containing a C-H bond. The shorter the wavelength of the emitted ultraviolet light, the higher the energy, and the impurity components or organic components also have a stronger absorption effect on short-wavelength ultraviolet light. In the embodiment of the present application, the main emission peak wavelength of the ultraviolet light emitted by the fluorescent powder layer under electron beam excitation is between 190 nm and 250 nm. The purity of the main component of the bonding oxide composed of inorganic particles is high, thereby effectively reducing the absorption of ultraviolet light by impurity components or organic components, and significantly improving the luminous efficiency.

[0081] Optionally, the main component of the bonding oxide is SiO2 or Al2O3. SiO2 or Al2O3 is resistant to electron beam bombardment, stable in nature, and has a small ultraviolet light absorption, thereby improving the emission intensity of ultraviolet light.

[0082] As an optional implementation, the main component of the bonding oxide is the same as the main component of the inner surface of the fluorescent screen part 21. The bonding oxide 411 and the inner surface of the fluorescent screen part can be chemically bonded through an oxygen bridge (—O—), that is, the bonding oxide 411 and the inner surface of the fluorescent screen can be chemically bonded through oxygen atoms, thereby improving the adhesion of the fluorescent powder 410 to the inner surface of the fluorescent screen. The main component of the inner surface of the fluorescent screen part 21 refers to the component with the highest proportion in the inner surface component of the fluorescent screen part 21. In a specific application, the fluorescent screen part 21 is quartz glass, the main component of the inner surface is SiO2, and the main component of the bonding oxide is SiO2. In another specific application, the fluorescent screen part 21 is a sapphire crystal, the main component of the inner surface is Al2O3, and the main component of the bonding oxide is Al2O3.

[0083] As another optional embodiment, a buffer layer (not shown in the figure) is further arranged between the phosphor screen part 21 and the phosphor layer 41, and the main component of the buffer layer is the same as that of the bonding oxide. The main component of the buffer layer refers to the component with the highest proportion in the buffer layer. Specifically, the buffer layer is arranged on the inner surface of the phosphor screen part 21, and the phosphor layer 41 is arranged on the buffer layer. For example, the buffer layer is in the form of a film, which is tightly formed on the inner surface of the phosphor screen part 21 by physical deposition (such as physical vapor deposition) or chemical deposition (such as chemical vapor deposition), and then the phosphor layer 41 is formed on the buffer layer. The main component of the buffer layer is the same as that of the bonding oxide 411 in the phosphor layer 41, and the two can be chemically bonded through an oxygen bridge, that is, the bonding oxide 411 in the phosphor layer 41 and the buffer layer are connected to each other through oxygen atoms to form a chemical bond, thereby improving the adhesion of the phosphor 410 to the inner surface of the phosphor screen.

[0084] As shown in Figure 11 An embodiment of the present application further provides a preparation method of the phosphor layer, specifically including the following steps:

[0085] S101, pour the adhesive oxide dispersion liquid into the glass shell; wherein the adhesive oxide dispersion liquid is composed of adhesive oxide and water. The PH value of the adhesive oxide dispersion liquid is between 6 and 8, and the concentration of the adhesive oxide in the adhesive oxide dispersion liquid is less than or equal to 5%, so that the adhesive oxide can be prevented from agglomerating together due to high concentration. Here, the adhesive oxide is an inorganic material composed of inorganic particles. Specifically, the particles of the adhesive oxide are nanoparticles with an average particle size of 1-100 nm. Optionally, the weight percentage of the main component of the adhesive oxide is greater than 99.9%, and the weight percentage of other impurity components is less than 0.1%. A high proportion of the main component of the adhesive oxide (i.e., high purity of the adhesive oxide) can effectively reduce the absorption of ultraviolet light by other impurity components and improve the luminous efficiency. The main component of the adhesive oxide refers to the component with the highest proportion in the adhesive oxide, which also plays a role in bonding. Specifically, the main component refers to the oxide in the adhesive oxide, and specifically to one kind of oxide; the other impurity components refer to the impurity components generated in the preparation process of the main component of the adhesive oxide. The adhesive oxide only contains inorganic components and does not contain organic components and organic residual components. It should be noted that the organic component in the embodiments of the present application refers to a compound containing a C-H bond. The adhesive oxide dispersion liquid of the present application is composed of adhesive oxide and water, so that the main component of the adhesive oxide in the finally formed fluorescent powder layer has higher purity, thereby reducing the absorption of ultraviolet light by impurity components in the adhesive oxide and improving the luminous intensity. As an embodiment, the main component of the adhesive oxide is SiO2, and correspondingly, the adhesive oxide dispersion liquid is a SiO2 dispersion liquid, the components in the SiO2 dispersion liquid are SiO2 particles and water, the average particle size of the SiO2 particles is between 1-100 nm, and the SiO2 particles are uniformly dispersed in water. Compared with using silicate solution (potassium silicate or sodium silicate) and electrolyte solution (such as barium nitrate or strontium nitrate) as a precipitating liquid, the present application directly uses the adhesive oxide in the adhesive oxide dispersion liquid as an adhesive to form a fluorescent powder layer through the adsorption of nanoparticles and the bonding effect between nanoparticles, without the need to form an adhesive through the reaction of silicate solution and electrolyte solution, so that the residual impurity ions (such as K, Na, Sr, Ba, etc.) or impurity components in the adhesive oxide are less, the absorption of emitted ultraviolet light by the impurity ions or impurity components is reduced, and the ultraviolet luminous intensity of the fluorescent powder layer is improved.As another embodiment, the main component of the bonding oxide is Al2O3, and the corresponding bonding oxide dispersion liquid is an Al2O3 dispersion liquid, the components of the Al2O3 dispersion liquid are Al2O3 particles and water, the average particle size of the Al2O3 particles is between 1-100 nm, and the Al2O3 particles are uniformly dispersed in the water; compared with using aluminate solution (potassium aluminate or sodium aluminate) and electrolyte solution (such as barium nitrate or strontium nitrate) as the precipitation liquid, the present application directly uses the bonding oxide in the bonding oxide dispersion liquid as the bonding agent, so that the residual impurity components or impurity ions (such as K, Na, Sr, Ba, etc.) in the phosphor layer are less, thereby reducing the absorption of the impurity ions to the emitted ultraviolet light and improving the ultraviolet light intensity of the phosphor layer.

[0086] S102, pour the phosphor into the glass shell containing the bonding oxide dispersion liquid. In actual preparation, a certain amount of phosphor is weighed by a balance and poured into the bonding oxide glass shell. The average particle size of the phosphor particles is between 1 μm-10 μm. Optionally, the ratio of the average particle size of the bonding oxide particles to the average particle size of the phosphor particles is between 1:1000-1:100. The phosphor includes at least one of the following: RePO4:Z1, LaP5O 14 :Z1, CaSO4:Z1, SrSO4:Z1, NaYF4:Z1, LiYF4:Z1, KYF4:Z1, LiLaP4O 12 :Z1, Y2(SO4)3:Z1, YAlO3:Z1, YF3:Z1; wherein Re represents one or more selected from Y, La, Lu, Sr, Gd, Sm, Ce, and Z1 represents a doping element containing one element selected from Nd, Pr, and Bi. As another optional embodiment, the phosphor includes at least one of the following: RePO4:Z2, LaP5O 14 :Z2, CaSO4:Z2, SrSO4:Z2, NaYF4:Z2, LiYF4:Z2, KYF4:Z2, LiLaP4O 12 :Z2, Y2(SO4)3:Z2, YAlO3:Z2, YF3:Z2; wherein Re represents one or more selected from Y, La, Lu, Sr, Gd, Sm, Ce, and Z2 represents a doping element containing two elements selected from Nd, Pr, and Bi, and Nd, Pr, and Bi can form energy transfer with each other under electron beam excitation to improve the ultraviolet light intensity. It should be noted that the phosphor is a pre-prepared phosphor; for example, a high-temperature solid-phase method is used to prepare: the phosphor raw materials are mixed and ground, then calcined at high temperature, and after grinding, washing, and drying, the required phosphor is obtained.

[0087] S103, stirring the poured fluorescent powder and the adhesive oxide dispersion liquid, and then standing for a certain time, so that the fluorescent powder is adhered on the bottom surface of the bulb by part of the adhesive oxide. The adhesive oxide is selected as nanoparticles with a particle size of 1-100 nm, and the surface of the nanoparticles has many active hydroxyl groups. During the standing process, due to the nano adsorption and gravity, part of the adhesive oxide particles will be tightly adsorbed on the surface of the fluorescent powder particles and precipitate to the bottom of the bulb with the fluorescent powder particles, and then the adhesive oxide particles are connected and polymerized into a network structure through oxygen atoms (i.e. oxygen bridge—O—) to adhere the fluorescent powder particles, and the adhesive oxide particles contacting the bottom surface of the bulb are also connected into a network structure to tightly adhere the fluorescent powder particles to the bottom surface of the bulb, that is, the fluorescent powder particles and the bottom surface of the bulb are tightly adhered by the adhesive oxide particles. It should be noted that the bottom surface of the bulb in the present application refers to the inner surface of the fluorescent screen part; the standing time needs to be determined according to the size of the fluorescent powder particles and the adhesive oxide particles and the volume of the adhesive oxide dispersion liquid, and generally needs 6-12 hours.

[0088] S104, removing the remaining adhesive oxide dispersion liquid in the bulb and drying to form a fluorescent powder layer on the bottom surface of the bulb. After standing, the adhesive oxide particles are adsorbed on the fluorescent powder particles and adhere the fluorescent powder particles together and between the fluorescent powder particles and the surface of the bulb, the remaining adhesive oxide dispersion liquid is poured out, and the bottom of the bulb will leave a fluorescent powder layer that is not dried, and after drying, the final fluorescent powder layer is formed, and the adhesive property is further enhanced by dehydration of the surface of the adhesive oxide during the drying process. In actual operation, the remaining adhesive oxide dispersion liquid in the bulb 20 can be removed by pouring out or sucking out. Optionally, the drying temperature is less than or equal to 100°C, and the drying time is between 6-12 hours. Since the fluorescent powder layer is formed by the mutual stacking of fluorescent powder particles and adhesive oxide particles under the action of gravity, there will be obvious pores between the particles, and the surface and the inside of the formed fluorescent powder layer also have pores. Optionally, the maximum diameter of the cross section of the pores on the surface and inside of the fluorescent powder layer in the direction perpendicular to the axis "A" is between 1 μm-10 μm. Optionally, the thickness of the fluorescent powder layer is between 5-50 μm.

[0089] In an optional embodiment, the preparation method of the fluorescent powder layer can include forming two or more layers of fluorescent powder layers stacked together, wherein at least one of the layers of fluorescent powder layers is formed by the above steps S101-S104. The main emission peak wavelength of the ultraviolet light emitted by each layer of fluorescent powder layers under electron beam excitation is different, and the wavelength of each main emission peak is below 300 nm; further, at least one of the wavelengths of the main emission peaks is between 190 nm-250 nm.

[0090] In practical applications, each of the two or more phosphor layers is formed by the steps S101-S104. In step S102, the phosphor types of the two or more phosphor layers are different. Specifically, the two or more phosphor layers include at least one different phosphor type. For example, the method of forming two phosphor layers includes: forming a first phosphor layer by the steps S101-S104; and forming a second phosphor layer by the steps S101-S104, wherein the first and second phosphor layers include at least one different phosphor type.

[0091] In another alternative embodiment, the method of forming the phosphor layer can include forming two or more sub-regional phosphor layers, wherein at least one of the sub-regional phosphor layers is formed by the steps S101-S104. The two or more sub-regional phosphor layers emit ultraviolet light having different main emission peak wavelengths. At least one of the sub-regional phosphor layers emits ultraviolet light having a main emission peak wavelength between 190 nm and 250 nm. Optionally, the two or more sub-regional phosphor layers include at least one different phosphor type. It is understood that the single phosphor layer includes two or more sub-regional phosphor layers, wherein the two or more sub-regional phosphor layers are located in the same layer, the lower surfaces of the two or more sub-regional phosphor layers are substantially coplanar, and the upper surfaces of the two or more sub-regional phosphor layers can also be substantially coplanar. The two or more sub-regional phosphor layers collectively form a single phosphor layer.

[0092] In practical applications, each of the two or more sub-regional phosphor layers is formed by the steps S101-S104. Before step S101, the method further includes: placing a sub-regional mask into the glass bulb 20, wherein the sub-regional mask exposes a sub-region to be formed. Optionally, the sub-regional mask can be rigid or flexible. For example, the method of forming two sub-regional phosphor layers includes: placing a first sub-regional mask into the glass bulb 20, wherein the first sub-regional mask exposes a first sub-region; forming a first sub-regional phosphor layer by the steps S101-S104; placing a second sub-regional mask into the glass bulb 20, wherein the second sub-regional mask exposes a second sub-region; forming a second sub-regional phosphor layer by the steps S101-S104; and wherein the first and second sub-regional phosphor layers include at least one different phosphor type.

[0093] The preparation method of the phosphor layer in the embodiment of the present application directly uses the bonding oxide dispersion liquid as the precipitation solution, the components of the dispersion liquid are the bonding oxide and water, and the bonding oxide is a nanoparticle. The phosphor layer is formed by using the nano effect and surface hydroxyl polymerization of the nanoparticle to bond the phosphor. Compared with the phosphor layer prepared by the traditional method, the preparation method in the embodiment of the present application is simpler and more convenient, the prepared phosphor layer does not contain organic components, and the residual impurity ions (such as K, Na, Sr, Ba and the like or impurity components) are less, so that the absorption of the impurity ions or impurity components to the emitted ultraviolet light is reduced, and the luminous intensity of the phosphor layer is improved.

[0094] As shown in Figure 12 the surface SEM diagram of the phosphor layer in the embodiment of the present application, it can be seen from the diagram that the surface of the phosphor layer has phosphor particles of different sizes, and the average particle size of the phosphor particles is between 1 μm and 10 μm. The surface of the phosphor is uneven, and has pores, and the maximum pore size is between 1 μm and 10 μm.

[0095] As shown in Figure 5 the embodiment of the present application, the light-emitting structure layer 40 further includes a conductive layer 42, and the conductive layer 42 is arranged on the phosphor layer 41. The conductive layer 42 is used to conduct the accumulated negative charge on the surface of the phosphor layer 41 out, so as to avoid the accumulated negative charge from reducing the energy of the electron beam due to the repulsion effect on the electron beam.

[0096] Optionally, the conductive layer 42 can be an aluminum film layer. Optionally, the thickness of the aluminum film layer is between 200 nm and 400 nm. The aluminum film layer can form a reflecting surface, and can reflect the ultraviolet light emitted by the phosphor layer 41 to the outer surface direction of the fluorescent screen part 21, so as to enhance the luminous intensity.

[0097] As shown in Figure 13 the embodiment of the present application, a preparation method of a light-emitting structure layer is further provided, which includes the following steps.

[0098] S201, forming a phosphor layer on a fluorescent screen part. Specifically, the phosphor layer can be formed by using the steps in the above embodiment of the preparation method of the phosphor layer.

[0099] S202, forming a conductive layer on the phosphor layer to obtain a light-emitting structure layer.

[0100] Specifically, forming the conductive layer on the phosphor layer includes the following steps.

[0101] The organic film layer is formed on the phosphor layer. The phosphor layer has pores inside, and forming the conductive layer directly on the phosphor layer will cause the phenomenon of "phosphor blackening", and it is also difficult to form mirror reflection on the uneven surface of the phosphor layer, which will finally affect the luminous intensity. In the embodiment of the application, a layer of organic film is formed on the phosphor layer, so that the adverse effects caused by directly forming the conductive layer can be avoided. It should be noted that "phosphor blackening" refers to the phenomenon that the conductive layer particles will enter the pores and mix with the phosphor particles together, thus causing the phosphor layer to become black, because there are many pores of hundreds of nanometers or even microns inside the phosphor layer. In "phosphor blackening", the conductive layer particles will strongly absorb the emitted ultraviolet light, thus seriously affecting the luminous intensity of the phosphor layer. Specifically, the phosphor layer is first wetted with pure water, so as to form a smooth film-forming surface on the uneven surface of the phosphor layer, and the surface tension of the solid powder layer is reduced, which is beneficial to the spreading of the organic film solution; then the organic film solution is added to the bulb to form a smooth film on the surface of the phosphor layer, wherein the organic film solution can be applied to the surface of the phosphor layer by spraying or spin coating; finally, the organic film on the surface of the phosphor is dried to form an organic film layer. The organic film solution mainly includes film-forming substances, solvents and plasticizers; the film-forming substances are the basic materials for forming the organic film, which can be nitrocellulose; the solvent is the main component of the volatile part of the organic film solution, which can be butyl acetate; the plasticizer is used to increase the flexibility of the organic film, which can be dimethyl phthalate. The organic film solution is greatly affected by composition, temperature and humidity, and the environmental conditions need to be strictly controlled during storage and use, otherwise the formed organic film plane will have problems such as unevenness and many pinholes, which will affect the formation of the subsequent conductive layer.

[0102] The first conductive layer is formed on the organic film layer. The first conductive layer can be an aluminum film layer with a thickness of 100-200 nm. Specifically, the first conductive layer can be formed on the organic film layer by evaporation.

[0103] The organic film layer is removed. Specifically, the bulb is heated at 200-400°C to remove the organic film layer, so that the first conductive layer directly covers the phosphor layer. Optionally, oxygen is introduced into the oven during the heating process, and the oxygen concentration in the oven is greater than 50%. Organic matter has strong absorption to ultraviolet light, especially ultraviolet light below 250 nm, and the residue of organic matter will seriously affect the luminous intensity of the phosphor layer. By introducing oxygen into the oven to increase the oxygen concentration, the hydrocarbons in the organic matter can be fully converted into CO2 and H2O, thereby reducing the residue of organic matter and improving the luminous intensity.

[0104] A second conductive layer is formed on the first conductive layer to obtain a light-emitting structure layer. The second conductive layer can be an aluminum film layer with a thickness between 100nm and 200nm. Specifically, the second conductive layer can be formed on the first conductive layer by vapor deposition. During the heating process to remove the organic film layer, gases are often released, causing small bulges or pinholes on the conductive layer. Simultaneously, the surface of the conductive layer is easily oxidized and contaminated during heating, reducing the light reflection efficiency of the conductive layer and ultimately affecting the light-emitting efficiency. In this application, the conductive layer is formed in two stages: first, a first conductive layer is formed using an organic film as a substrate; then, after removing the organic film, a second conductive layer is formed on the first conductive layer. Therefore, even if the first conductive layer suffers oxidation contamination or pinholes, the second conductive layer can compensate for the defects of the first conductive layer, resulting in a bright and smooth light-reflecting surface in the final conductive layer.

[0105] In the method for preparing the luminescent structure layer in this application embodiment, the phosphor layer directly uses the adhesive oxide dispersion as the precipitate, resulting in fewer residual impurity ions and thus reducing the absorption of ultraviolet light by the impurity ions; at the same time, the conductive layer is formed in two stages, thereby forming a bright and smooth reflective surface; the final luminescent structure layer has a higher luminous intensity.

[0106] like Figure 14 As shown, in an optional embodiment, the light-emitting structural layer 40 further includes a filling oxide 440, which is used to fill the surface and internal pores of the phosphor layer 41. Optionally, the structural layer formed after the phosphor layer 41 is filled with the filling oxide 440 is defined as a first structural layer 44, that is, the first structural layer 44 includes the phosphor layer 41 and the filling oxide 440. Optionally, the filling oxide 440 is an inorganic material composed of inorganic particles. Optionally, at least a portion of the filling oxide 440 fills the surface and internal pores of the phosphor layer 41.

[0107] Optionally, the ratio of the average particle size of the oxide 440 filler particles to the average particle size of the phosphor particles is between 1:1000 and 1:100. The particle size of the oxide 440 filler particles is much smaller than that of the phosphor particles. By filling with oxide 440, the surface and internal pore size of the phosphor layer 41 can be significantly reduced, thereby effectively reducing the "phosphor blackening" phenomenon. Optionally, the oxide 440 filler particles are nanoparticles with an average particle size between 1 nm and 50 nm.

[0108] Optionally, the structure layer formed after the phosphor layer 41 is filled with the filling oxide 440 is defined as the first structure layer 44, the first structure layer 44 includes phosphor particles, adhesive oxide particles and filling oxide particles, and the maximum diameter of the cross section of the internal pores of the first structure layer 44 in the direction parallel to the inner surface of the screen part 21 is less than 1 μm. Further, the maximum diameter of the cross section of the internal pores of the first structure layer 44 in the direction parallel to the inner surface of the screen part 21 is less than or equal to 50 nm. The present application fills the internal pores of the phosphor layer with the filling oxide composed of nanoparticles, thereby reducing the size of the internal pores of the phosphor layer, and the conductive layer can be formed directly on the phosphor layer without using an organic film. On the one hand, the organic film does not cause the residue of organic matter, thereby reducing the absorption of ultraviolet light. On the other hand, the reduction of the pores can effectively reduce the phenomenon of "blackening of phosphor", thereby improving the luminous intensity. Meanwhile, the filling oxide filled in the internal pores of the phosphor layer can form a light guide structure composed of the filling oxide, and the light generated by the phosphor layer can be transmitted and emitted through the light guide structure, thereby effectively reducing the loss of ultraviolet light in the process of transmission in the internal pores, and improving the luminous intensity.

[0109] In an optional embodiment, the surface of the first structure layer 44 is composed of phosphor particles, adhesive oxide particles and filling oxide particles. Compared with the surface of the phosphor layer 41, the size of the filling oxide particles is much smaller than that of the phosphor particles, and therefore the surface of the first structure layer 44 formed after the filling oxide particles fill the surface of the phosphor layer 41 is more flat and dense.

[0110] In another optional embodiment, the surface of the first structure layer 44 is composed of filling oxide particles, that is, the filling oxide 440 not only fills the surface and internal pores of the phosphor layer 41, but also covers the surface of the phosphor layer 41, thereby forming the smooth and dense surface of the first structure layer 44. Optionally, the surface of the first structure layer 44 has crack-like pores with a maximum width of less than 1 μm.

[0111] Optionally, the conductive layer 42 is arranged on the first structure layer 44. The filling oxide 440 greatly reduces the size of the internal and surface pores of the phosphor layer 41, and the size of the pores can be reduced from several microns to tens of nanometers or even several nanometers, thereby greatly reducing the phenomenon of "blackening of phosphor" caused by the mixing of the particles in the conductive layer and the particles of the phosphor. Optionally, the conductive layer can be an aluminum film layer with a thickness of 50 nm-400 nm, and further, the thickness of the aluminum film layer is 50 nm-100 nm. The surface of the first structure layer 44 is flat and dense, the thickness of the conductive layer 42 is thinner and can also meet the requirement of conductivity, and the thinner conductive layer can also reduce the absorption of the electron beam energy, thereby improving the luminous efficiency.

[0112] Optionally, the weight percentage of the main component of the filling oxide is greater than 99.9%, and the weight percentage of other impurity components is less than 0.1%. The main component of the filling oxide refers to the component with the highest proportion in the filling oxide 440, and is also the component that plays a filling role in the filling oxide 440. Specifically, the main component refers to the oxide in the filling oxide 440, and specifically refers to one kind of oxide; the other impurity components refer to the impurity components generated in the preparation process of the main component of the filling oxide. The filling oxide 440 only contains inorganic components, and does not contain organic components and organic residual components.

[0113] Optionally, the main component of the filling oxide can be SiO2 or Al2O3. SiO2 or Al2O3 is resistant to electron beam bombardment, stable in nature, and has small ultraviolet light absorption, thereby reducing the influence on the luminous intensity.

[0114] As an optional implementation, the main component of the filling oxide is the same as the main component of the bonding oxide. Therefore, the filling oxide 440 and the bonding oxide 411 can be chemically bonded through an oxygen bridge (—O—), that is, the filling oxide 440 and the bonding oxide 411 can be chemically bonded to each other through oxygen atoms, thereby improving the adhesion of the filling oxide 440 and the fluorescent powder layer 41. In a specific application, the main component of the bonding oxide is SiO2, and the main component of the filling oxide is SiO2. In another specific application, the main component of the bonding oxide is Al2O3, and the main component of the filling oxide is Al2O3.

[0115] As shown in FIG. 1, the first structure layer is provided on the surface of the fluorescent screen part. The first structure layer includes a fluorescent powder layer and a filling oxide. The fluorescent powder layer includes fluorescent powder and a bonding oxide. The bonding oxide is used to bond the particles of the fluorescent powder and the surface of the fluorescent screen part together. The filling oxide is an inorganic material. At least part of the filling oxide fills the internal pores of the fluorescent powder layer. Figure 15 As shown in FIG. 2, it is a first structure layer surface SEM diagram of an embodiment of the present application. It can be seen from the figure that, relative to the surface of the fluorescent layer, the surface of the first structure layer is flat and dense, and there is no obvious particulate matter. The first structure layer surface shown in the figure has crack-like pores, and the maximum width of the pores is less than 1 μm.

[0116] Based on this, the embodiment of the present application further provides a fluorescent screen. The fluorescent screen includes a fluorescent screen part and a first structure layer. The first structure layer is provided on the fluorescent screen part. The first structure layer includes a fluorescent powder layer and a filling oxide. The fluorescent powder layer includes fluorescent powder and a bonding oxide. The bonding oxide is used to bond the particles of the fluorescent powder and the surface of the fluorescent screen part together. The filling oxide is an inorganic material. At least part of the filling oxide fills the internal pores of the fluorescent powder layer. Optionally, the fluorescent screen further includes a conductive layer. The conductive layer is provided on the first structure layer.

[0117] It can be understood that the screen part in the embodiment can be the screen part described above, or other support substrates, so that the first structure layer is arranged on the screen part. Of course, the embodiments of the present application are not limited thereto, and any screen according to the screen provided in the embodiments of the present application should belong to the protection scope of the present application. In addition, other technical features described in the embodiments can be the same as the foregoing embodiments, which will not be described here. Specifically as Figure 14 As shown in FIG. 4, the screen 45 includes the screen part 10, the first structure layer 44 and the conductive layer 42. In the screen of the embodiment of the present application, the fluorescent powder layer is filled with the filling oxide, so that the pores inside the fluorescent powder layer can be greatly reduced, and the phenomenon of "blackening of fluorescent powder" can be effectively reduced in the process of directly forming the conductive layer on the fluorescent powder layer, and the luminous intensity is improved. At the same time, the filling oxide can form a light guide structure composed of the filling oxide after filling the pores inside the fluorescent powder layer, and the light generated by the fluorescent powder layer can be transmitted and emitted through the light guide structure, effectively reducing the absorption and scattering of ultraviolet light in the internal pores during transmission, thereby enhancing the luminous intensity.

[0118] The embodiment of the present application also provides an ultraviolet cathode-ray tube, which includes the screen, the electron gun, the tubular part for accommodating the electron gun and the electric lead assembly electrically connected with the electron gun in the above-mentioned embodiments; wherein the tubular part is connected with the screen part; the electron gun is arranged in the tubular part and used for emitting an electron beam to the screen part; the fluorescent powder layer in the first structure layer arranged on the screen part emits light under the excitation of the electron beam; and the electron gun is electrically connected with the outside through the electric lead assembly.

[0119] As shown in FIG. 4, the screen 45 includes the screen part 10, the first structure layer 44 and the conductive layer 42. In the screen of the embodiment of the present application, the fluorescent powder layer is filled with the filling oxide, so that the pores inside the fluorescent powder layer can be greatly reduced, and the phenomenon of "blackening of fluorescent powder" can be effectively reduced in the process of directly forming the conductive layer on the fluorescent powder layer, and the luminous intensity is improved. At the same time, the filling oxide can form a light guide structure composed of the filling oxide after filling the pores inside the fluorescent powder layer, and the light generated by the fluorescent powder layer can be transmitted and emitted through the light guide structure, effectively reducing the absorption and scattering of ultraviolet light in the internal pores during transmission, thereby enhancing the luminous intensity. Figure 16 As shown in FIG. 4, the screen 45 includes the screen part 10, the first structure layer 44 and the conductive layer 42. In the screen of the embodiment of the present application, the fluorescent powder layer is filled with the filling oxide, so that the pores inside the fluorescent powder layer can be greatly reduced, and the phenomenon of "blackening of fluorescent powder" can be effectively reduced in the process of directly forming the conductive layer on the fluorescent powder layer, and the luminous intensity is improved. At the same time, the filling oxide can form a light guide structure composed of the filling oxide after filling the pores inside the fluorescent powder layer, and the light generated by the fluorescent powder layer can be transmitted and emitted through the light guide structure, effectively reducing the absorption and scattering of ultraviolet light in the internal pores during transmission, thereby enhancing the luminous intensity.

[0120] S301, providing a screen part.

[0121] S302, forming a fluorescent powder layer on the screen part.

[0122] Specifically, the fluorescent powder layer can be formed by using the steps in the embodiments of the preparation method of the fluorescent powder layer described above.

[0123] S303, filling the fluorescent powder layer with the filling oxide to form a first structure layer including the fluorescent powder layer and the filling oxide; wherein at least part of the filling oxide is filled in the internal pores of the fluorescent powder layer, and at least another part of the filling oxide is formed on the surface of the fluorescent powder layer.

[0124] The filling of the oxide filler in the fluorescent powder layer comprises: adding the oxide filler dispersion liquid to the fluorescent powder layer, i.e. pouring the oxide filler dispersion liquid into the glass shell. The oxide filler dispersion liquid comprises the oxide filler and water, and the liquid level of the oxide filler dispersion liquid is flush with or slightly higher than the surface of the fluorescent powder layer; and the oxide filler is filled in the internal pores of the fluorescent powder layer after being left to dry for a certain period of time. The concentration of the oxide filler in the oxide filler dispersion liquid is less than or equal to 30%. Here, the oxide filler is an inorganic material composed of inorganic particles. Optionally, the ratio of the average particle size of the oxide filler to the average particle size of the fluorescent powder is between 1:1000 and 1:100. Optionally, the particles of the oxide filler are nanoparticles with an average particle size of between 1 nm and 50 nm. During the standing process, the oxide filler dispersion liquid is filled into the surface and internal pores of the fluorescent layer due to the capillary force and gravity, and after drying, the water is removed, the particles of the oxide filler are filled in the surface of the fluorescent powder layer and the pores inside the fluorescent powder layer, and at the same time, a first structure layer surface is formed which is more compact and flat relative to the fluorescent powder layer. Optionally, the weight percentage of the main component in the oxide filler is greater than 99.9%, and the weight percentage of other impurity components is less than 0.1%. The main component refers to the component with the highest proportion in the oxide filler, which also plays a bonding role in the oxide filler. Specifically, the main component refers to the oxide in the oxide filler, and specifically to one kind of oxide; and the other impurity components refer to the impurity components generated in the preparation process of the main component of the oxide filler. The oxide filler only contains inorganic components and does not contain organic components and organic residual components. As an embodiment, the oxide filler dispersion liquid is a SiO2 dispersion liquid, and correspondingly, the main component of the oxide filler is SiO2. As another embodiment, the oxide filler dispersion liquid is an Al2O3 dispersion liquid, and correspondingly, the main component of the oxide filler is Al2O3. The oxide filler dispersion liquid used in the embodiments of the present application contains the oxide filler and water and does not contain other organic components, and the impurity ions in the dispersion liquid are also very few (only including the impurity components generated in the preparation process of the main component of the oxide filler), so that the pores of the fluorescent powder layer can be filled and a more compact and flat surface is formed, and more impurity components are not introduced.

[0125] S304, directly forming a conductive layer on the first structure layer. Specifically, the conductive layer can be formed on the first structure layer by evaporation. Optionally, the conductive layer can be an aluminum film layer, and the thickness of the aluminum film layer is between 50 nm and 400 nm. Further, the thickness of the aluminum film layer is between 50 nm and 100 nm. The first structure layer is flat and dense, and the conductive layer can be directly formed on the first structure layer without forming an organic film, and the conductive layer can be formed with a smaller thickness to meet the conductive requirement. The method of the embodiment directly forms the conductive layer on the first structure layer, and compared with the process of forming an organic film, forming a conductive layer, and removing the organic film, the method of the embodiment is simpler and more environmentally friendly, and the method of the embodiment also does not have the problem of residual organic matter caused by removing the organic film.

[0126] The preparation method of the fluorescent screen of the embodiment fills the pores on the surface and in the interior of the fluorescent powder layer with the filling oxide, forms a more dense and flat surface, greatly reduces the size of the pores in the interior of the fluorescent powder layer, and thus can reduce or even avoid the phenomenon of "blackening of fluorescent powder" caused by the mixing of particles in the conductive layer and particles of the fluorescent powder. Compared with the process using the organic film, the preparation method of the embodiment fills the pores in the interior of the fluorescent powder layer with the filling oxide, and then directly forms the conductive layer, and thus the preparation method is simple and more environmentally friendly, and the preparation method also does not have the problem of residual organic matter caused by removing the organic film, avoids the absorption of ultraviolet light by the residual organic matter, and improves the luminous efficiency.

[0127] As Figure 17 FIG. 1 is a schematic diagram of an electron gun structure according to an embodiment of the present application. In the figure, the electron gun 30 is an area projection type electron gun, and specifically includes a cathode assembly 31 and an electrode assembly 32. It should be noted that the area projection type electron gun refers to the electron beam emitted by the electron gun to the fluorescent screen part being emitted in an area projection manner.

[0128] The cathode 310 assembly 31 comprises a cathode tube 311, a cathode 310 and a filament 312. The cathode tube 311 is a cylindrical metal tube comprising a closed end and an open end. The cathode 310 is arranged on the outer surface of the closed end of the cathode tube 311. The filament 312 is arranged in the cathode tube 311 and close to the closed end of the cathode tube 311. Optionally, the cathode 310 emits electrons and forms a cathode 310 emission surface. The cathode 310 can be a planar cathode. The planar cathode refers to a cathode 310 material processed into a block. When the planar cathode emits electrons, the electron beam emitted from a planar surface is more uniform, and it is easier to form a uniform cathode emission surface. Optionally, the planar cathode can be ring-shaped. The ring-shaped cathode is beneficial to reduce the electron beam density in the middle of the cathode 310 emission surface, thereby improving the uniformity of the electron beam. Optionally, the material of the cathode 310 is an oxide, i.e., the cathode 310 is an oxide cathode. The oxide cathode has the advantages of high melting point, high resistivity, small work function and long service life. The oxide cathode used in the embodiment of the present application can make the electron gun emit electrons stably, and the service life can reach tens of thousands of hours. Further, the material of the cathode 310 is a mixture of BaCO3, SrCO3 and CaCO3. Optionally, the outer diameter of the cathode tube 311 is 1.6 mm ± 0.02 mm. In specific operation, the current flows through the filament 312 in the cathode assembly. The filament 312 heats the cathode 310 on the outer surface of the closed end of the cathode tube 311. When the temperature reaches the temperature required for the cathode 310 to emit electrons, the cathode 310 emits electrons.

[0129] The electrode assembly 32 comprises a plurality of metal cylinders, each of which is axisymmetric along the longitudinal central axis "A". The plurality of metal cylinders are all made of non-magnetic metal materials. Further, the plurality of metal cylinders are made of non-magnetic stainless steel. Optionally, the electron beam emitted by the cathode 310 hits the fluorescent screen part 21 in an area projection manner after passing through the electrode assembly 32. The projection surface of the area projection is the first inverted image of the emission surface of the cathode 310. It should be noted that the electron beam hits the fluorescent screen part 21 in an area projection manner, which means that the electron beam forms a projection surface in a scattered manner. In contrast, the focusing manner refers to a point rather than a surface.

[0130] The plurality of metal cylinders comprise a cathode modulation zone metal cylinder G1, an electron beam modulation zone metal cylinder G2 and an electron beam acceleration zone metal cylinder G3. Optionally, the plurality of metal cylinders are respectively connected to independent input voltages, so that their input voltages can be independently controlled and can be the same or different. Optionally, the inner diameters of the plurality of metal cylinders are between 3 mm and 15 mm.

[0131] The number of electrons emitted by the cathode 310 can be adjusted by controlling the potential of the cathode modulation zone metal cylinder G1 and the potential of the cathode 310, thereby changing the size of the electron beam. Optionally, the potential of the cathode modulation zone metal cylinder G1 is 0V-20V. Optionally, the potential of the cathode modulation zone is greater than or equal to the potential of the cathode 310. The cathode modulation zone metal cylinder G1 is sleeved outside the cathode tube 311, and the end of the cathode modulation zone metal cylinder G1 is provided with a small hole with a diameter of 2mm-3mm. Optionally, the cathode 310 is flush with or slightly protrudes from the end of the cathode modulation zone metal cylinder G1, that is, the cathode 310 is flush with or passes through the small hole in the end of the cathode modulation zone metal cylinder G1, so that the influence of the electric field in the cathode modulation zone on the emission direction of the electron beam can be reduced, thereby improving the uniformity of the emission surface of the cathode 310. Optionally, the distance between the cathode 310 and the end of the cathode modulation zone metal cylinder G1 is 0.01mm-0.03mm.

[0132] The electron beam modulation region metal cylinder G2 is used to control the electron beam shape in the region. Optionally, the electron beam modulation region metal cylinder G2 comprises a plurality of sub-beam modulation region metal cylinders, each of which is connected to an independent input voltage, and the input voltages thereof can be independently controlled, which can be the same or different, so as to accurately control the electron beam shape in the region; meanwhile, the plurality of sub-beam modulation region metal cylinders can more conveniently and flexibly control the electron beam shape. Optionally, the spacing between each sub-beam modulation region metal cylinder is the same; further, the spacing between each sub-beam modulation region metal cylinder is less than or equal to 1 mm. Optionally, the spacing between the cathode modulation region metal cylinder G1 and the sub-beam modulation region metal cylinder adjacent to the cathode modulation region metal cylinder G1 is less than or equal to 1 mm. Optionally, the inner diameters of the sub-beam modulation region metal cylinders are the same; further, the inner diameters of the sub-beam modulation region metal cylinders are 10 ± 0.1 mm. Optionally, the inner diameter of the sub-beam modulation region metal cylinder adjacent to the cathode modulation region metal cylinder G1 is greater than or equal to the inner diameter of the cathode modulation region metal cylinder G1, so as to make the curve of the electric field force in a divergent state, and more conveniently control the uniform divergence of the electron beam. Optionally, the potential of each sub-beam modulation region metal cylinder is 0 V-50 V. Optionally, the potential of the sub-beam modulation region metal cylinder adjacent to the cathode modulation region is greater than the potential of the cathode modulation region metal cylinder. By controlling the inner diameter and potential of the metal cylinder, the electron beam shape can be conveniently adjusted to make the electron beam uniformly diverge. Optionally, in the two adjacent sub-beam modulation region metal cylinders, the potential of the sub-beam modulation region metal cylinder far from the cathode 310 is greater than or equal to the potential of the sub-beam modulation region metal cylinder close to the cathode 310, so as to better adjust the electric field direction and control the electron beam shape. Optionally, in the two adjacent sub-beam modulation region metal cylinders, the length of the sub-beam modulation region metal cylinder far from the cathode 310 is greater than the length of the sub-beam modulation region metal cylinder close to the cathode 310. Optionally, the potential of the electron beam modulation region metal cylinder G2 can be controlled in a pulse mode to realize pulse light emission of the light-emitting structure layer. It should be noted that the spacing between the metal cylinders refers to the distance between the adjacent two end faces of the two metal cylinders. In the embodiments of the present application, the size and potential of the electron beam modulation region metal cylinder can be conveniently and flexibly controlled to control the electron beam shape; meanwhile, the pulse frequency of the potential of the electron beam modulation region metal cylinder can be adjusted to control the light-emitting frequency of the light-emitting structure layer, so as to have a wide application prospect in the field of ultraviolet communication. Further, the electron beam modulation region metal cylinder G2 comprises two sub-beam modulation region metal cylinders, specifically a first sub-electron beam modulation region metal cylinder G21 and a second sub-electron beam modulation region metal cylinder G22; through coordinated control of the two sub-beam modulation region metal cylinders, on the one hand, the electron beam shape can be flexibly adjusted through the potential and the size of the metal cylinder, and on the other hand, the number of electric leads connected thereto can be reduced, so as to reduce the air leakage rate between the electric leads and the closed part.

[0133] The electron beam acceleration zone metal cylinder G3 is used to form a strong electric field to accelerate the electron beam to a very fast speed to bombard the fluorescent screen part 21. Optionally, the potential of the electron beam acceleration zone metal cylinder G3 is a high voltage potential, specifically 5kV-20kV. Optionally, the inner diameter of the electron beam acceleration zone metal cylinder G3 is smaller than the inner diameter of the sub-beam modulation zone metal cylinder adjacent to the electron beam acceleration zone metal cylinder G3. The electron beam after passing through the electron acceleration zone metal cylinder is projected in an area projection manner, and the area projection projection surface is a first inverted image of the cathode emission surface. In the embodiment of the application, the inner diameter of the electron beam acceleration zone metal cylinder is smaller than the inner diameter of the adjacent sub-beam modulation zone metal cylinder, thereby reducing the electric field range, and further modulating the direction of the electron beam through the potential, so that the electron beam can be focused first and then divergent to form a first inverted image, thereby improving the uniformity of the electron beam, and finally bombarding the fluorescent screen part in an area projection manner, and the area projection projection surface of the final electron beam is a first inverted image of the cathode emission surface. The electron gun of the embodiment of the application emits the electron beam in an area projection manner, so that the fluorescent powder on the fluorescent screen part can be excited at the same time. At the same time, the area projection projection surface of the electron beam is a first inverted image of the cathode emission surface, thereby improving the uniformity of the electron beam, and the application to the light emitting device is conducive to improving the uniformity of the light emitting device.

[0134] Optionally, the distance between the electron beam acceleration zone metal cylinder G3 and the sub-beam forming zone metal cylinder adjacent to the electron beam acceleration zone metal cylinder G3 is 1mm-3mm.

[0135] Specifically, for example Figure 17 As shown in the figure, the electrode assembly 32 includes a cathode modulation zone metal cylinder G1, an electron beam modulation zone metal cylinder G2, and an electron beam acceleration zone metal cylinder G3, wherein the electron beam modulation zone metal cylinder G2 includes a first sub-electron beam modulation zone metal cylinder G21 and a second sub-electron beam modulation zone metal cylinder G22. Specifically, the inner diameter of the metal cylinder is G3 < G1 < G21 = G22; the potential of the cathode modulation zone metal cylinder G1 is 0V-20V under the electrified state; the potentials of G21 and G22 are both greater than the potential of G1, and the potentials of G21 and G22 are 0-50V; G3 is a high voltage potential, specifically 5kV-20kV. The distance between G1 and G21 is 0.5mm, the distance between G21 and G22 is 0.5mm, and the distance between G22 and G3 is 2mm; the length of G1 in the plurality of metal cylinders is 8mm, the length of G21 is 5mm, the length of G22 is 8.5mm, and the length of G3 is 5mm.

[0136] As Figure 1 shown, the cathode ray tube 10 of the embodiment of the application further includes an electric lead assembly 50, and the electron gun 30 is electrically connected to the outside through the electric lead assembly 50.

[0137] As Figure 18Fig. 1 is a schematic view of an embodiment of the electric lead assembly of the present application. In Fig. 1, the electric lead assembly 50 penetrates the closed portion 23, so that one end of the electric lead assembly 50 is exposed from the closed portion 23, and the other end is connected with the electron gun 30 in the tubular portion 22. The electron gun 30 is connected with the external circuit through the electric lead assembly 50. Optionally, the electric lead assembly 50 includes a plurality of electric leads 500. At least some of the plurality of electric leads are electrically connected with the electrode assembly 32 and / or the cathode assembly 31. The electrode assembly 32 and / or the cathode assembly 31 are electrically connected with the external circuit through the electric leads. Specifically, the plurality of metal cylinders in the electrode assembly 32 are respectively connected with different electric leads. The different electric leads are respectively connected with independent input voltages from the outside, so that the input voltages of the plurality of metal cylinders can be independently controlled.

[0138] Optionally, the electric lead assembly 50 includes at least four electric leads.

[0139] Optionally, at least one electric lead is electrically connected with the metal cylinder in the electron beam acceleration zone. By electrically connecting the electric lead with the metal cylinder in the electron beam acceleration zone, the external circuit can directly provide a high voltage of 5kV-20kV for the electron beam acceleration zone through the electric lead. The connection is more convenient and simple, so that the anode metal rod for connecting the high voltage on the glass bulb 20 can be avoided.

[0140] Optionally, the electric lead 500 includes an upper metal wire 501, a middle metal sheet 502 and a lower metal wire 503. The middle metal sheet 502 is connected with the upper metal wire 501 and the lower metal wire 503. The middle metal sheet 502 is enclosed in the closed portion 23. A part of the upper metal wire 501 is enclosed in the closed portion 23, and the other part of the upper metal wire 501 is exposed from the closed portion 23 for connecting with the external circuit. A part of the lower metal wire 503 is enclosed in the closed portion 23, and the other part of the lower metal wire 503 is connected with the cathode assembly 31 and / or the electrode assembly 32. For the case that the electric lead assembly 50 includes a plurality of electric leads 500, each of the plurality of electric leads 500 can have the same structure. Each of the plurality of electric leads 500 can include the upper metal wire 501, the middle metal sheet 502 and the lower metal wire 503. Of course, the embodiment of the present application does not exclude the case that the plurality of electric leads 500 have different structures. The sealing condition of the closed portion 23 directly affects the air tightness in the glass bulb. The thermal expansion coefficient of the electric lead is greatly different from the thermal expansion coefficient of the glass bulb. By using the thin metal sheet and the flat closed portion, the metal sheet can be better enclosed in the closed portion, so that the air tightness is maintained.

[0141] Optionally, the edge of the intermediate metal sheet 502 in the direction of the axis A is knife-edged. During the forming of the closure portion 23, a stretching force is generated, and the knife-edged edge of the intermediate metal sheet 502 in the direction of the stretching of the closure portion 23 can be slightly plastically deformed by the stretching force, so that the intermediate metal sheet 502 can be better closed by the closure portion 23, and good sealing is formed. It should be noted that the knife-edged shape in the embodiment of the present application is that the thickness of the intermediate metal sheet gradually decreases from the edge, for example, the thickness of the intermediate metal sheet near the edge is 0.6 mm, and the thickness of the edge is 0.1 mm, and the thickness gradually decreases from the edge to the edge.

[0142] Optionally, the electric lead assembly 50 further comprises a fixing column 51, and the lower end metal wire 503 is connected to the intermediate metal sheet 502 after penetrating through the fixing column 51, and the fixing column 51 is used to fix the electric lead and prevent the electric lead from being bent and deformed, so as to avoid the mutual contact between the plurality of electric leads. Optionally, the material of the fixing column 51 is quartz glass, which is more heat-insulating and high-temperature-resistant, so as to avoid the influence of high-temperature heating.

[0143] Optionally, the electric lead assembly 50 further comprises a connecting sheet 55, and the lower end metal wire 503 is electrically connected to the electron gun 30 through the connecting sheet 55. Specifically, the lower end metal wire 503 is connected to the connecting sheet 55 by welding, and the connecting sheet 55 is connected to the electron gun 30 through a metal wire 57. Optionally, the connecting sheet 55 is L-shaped, so as to occupy smaller space and make the connection more convenient. Optionally, the material of the electric lead 500 is molybdenum. Optionally, the material of the connecting sheet 55 is stainless steel, and the material of the metal wire 57 is stainless steel. Optionally, the electric lead assembly 50 further comprises a buffer metal sheet 56. Specifically, the lower end metal wire 503 is connected to the connecting sheet 55 through the buffer metal sheet 56, the buffer metal sheet 56 is welded on the connecting sheet 55, the lower end metal wire 503 is welded on the buffer metal sheet 56, and the connecting sheet 55 is connected to the electrode assembly 32 or the cathode assembly 31 through the metal wire 57. Optionally, the material of the buffer metal sheet 56 is nickel. By the buffer metal sheet and the connecting sheet, the poor connection caused by the different thermal expansion coefficients of the materials can be reduced, and the stability of the connection is improved.

[0144] Optionally, the cross-sectional diameters of the upper end metal wire 501 and the lower end metal wire 503 are greater than the central thickness of the intermediate metal sheet 502.

[0145] Optionally, the cross-sectional diameters of the upper end metal wire 501 and the lower end metal wire 503 are between 0.5 mm and 0.8 mm.

[0146] Optionally, the central thickness of the intermediate metal sheet 502 is between 0.1mm and 0.4mm. Optionally, the intermediate metal sheet 502 is a rectangular metal sheet, and the long side of the rectangular metal sheet extends along the direction of the A-axis, and the length of the long side is greater than or equal to 10mm. It should be understood that the thickness of the intermediate metal sheet in the embodiments of the present application is basically the same except for the position of the blade-shaped edge. The central thickness of the intermediate metal sheet 502 refers to the thickness of the region of the intermediate metal sheet 502 except for the position of the blade-shaped edge.

[0147] The ultraviolet cathode ray tube provided by the embodiments of the present application comprises a glass bulb, a light-emitting structure layer, an electron gun, and an electric lead assembly electrically connected with the electron gun, and emits ultraviolet light by exciting the light-emitting structure layer through the electron gun. The ultraviolet cathode ray tube of the present application has high light-emitting efficiency, high light-emitting energy, no pollution, low cost, and is easy to mass-produce.

[0148] The above-described specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above-described specific embodiments are merely specific embodiments of the present application, and are not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application. The technical features in each of the above-described specific embodiments can be combined arbitrarily without conflict.

Claims

1. A method for preparing a fluorescent screen, characterized in that, The method includes: Provide fluorescent screen section; A phosphor layer is formed on the fluorescent screen portion; the phosphor layer includes phosphor and bonding oxide; The phosphor layer is filled with a filling oxide to form a first structural layer with a dense and flat surface; the first structural layer includes the phosphor layer and the filling oxide, wherein the filling oxide is an inorganic material, at least a portion of the filling oxide fills the internal pores of the phosphor layer, and at least another portion of the filling oxide is formed on the surface of the phosphor layer; A conductive layer is formed directly on the first structural layer. The conductive layer is an aluminum film layer with a thickness between 50-100 nm.

2. The method for preparing a fluorescent screen as described in claim 1, characterized in that, Forming a phosphor layer on the fluorescent screen specifically includes: The adhesive oxide dispersion is poured into a glass shell; wherein the adhesive oxide dispersion consists of adhesive oxide and water; the average particle size of the adhesive oxide particles is between 1 nm and 100 nm; the fluorescent screen is the bottom of the glass shell; The phosphor is poured into a glass shell containing the adhesive oxide dispersion; wherein the average particle size of the phosphor particles is between 1 μm and 10 μm. The solution containing the phosphor and the adhesive oxide dispersion is stirred and then allowed to stand for a certain period of time, so that the phosphor is partially adhered to the bottom surface of the glass shell by the adhesive oxide. Remove the remaining solution inside the glass shell and dry the glass shell so that the phosphor adhering to the bottom surface of the glass shell dries to form a phosphor layer.

3. The method for preparing a fluorescent screen as described in claim 1, characterized in that, The process of filling the phosphor layer with a filling oxide specifically includes: A filled oxide dispersion is added to the phosphor layer, wherein the filled oxide dispersion consists of the filled oxide and water; Allow the mixture to stand and dry for a certain period of time to allow some of the filling oxide to fill the internal pores of the phosphor layer.

4. The method for preparing a fluorescent screen as described in claim 3, characterized in that, The concentration of the filled oxide in the filled oxide dispersion is less than or equal to 30%.

5. The method for preparing a fluorescent screen as described in claim 1, characterized in that, The phosphor layer includes phosphor, the average particle size of the phosphor particles is between 1 μm and 10 μm, and the average particle size of the oxide-filled particles is between 1 nm and 50 nm.

6. The method for preparing a fluorescent screen as described in claim 5, characterized in that, The phosphor layer also includes an adhesive oxide, which is used to bond the phosphor particles together and to bond the phosphor particles to the surface of the phosphor screen. The main components of the adhesive oxide are the same as those of the filler oxide.

7. The method for preparing a fluorescent screen as described in claim 1, characterized in that, The main component of the filling oxide is SiO2 or Al2O3, and the filling oxide dispersion is a SiO2 dispersion or an Al2O3 dispersion.

8. The method for preparing a fluorescent screen as described in claim 1, characterized in that, The conductive layer is an aluminum film with a thickness between 50-100 nm.

9. A fluorescent screen prepared by any one of the fluorescent screen preparation methods described in claims 1-8, characterized in that, The fluorescent screen includes: Fluorescent screen; A first structural layer is disposed on the fluorescent screen portion; The first structural layer includes a phosphor layer and a filling oxide; the phosphor layer includes phosphor and a bonding oxide, the bonding oxide being used to bond the phosphor particles to the surface of the phosphor screen. The filling oxide is an inorganic material; The filling oxide is used to fill the surface and internal pores of the phosphor layer; at least a portion of the filling oxide is filled in the surface and internal pores of the phosphor layer.

10. The fluorescent screen as described in claim 9, characterized in that, The maximum diameter of the cross-section of the internal pores of the first structural layer in the direction parallel to the surface of the fluorescent screen is less than 1 μm.

11. The fluorescent screen as described in claim 10, characterized in that, The maximum diameter of the cross-section of the internal pores of the first structural layer in the direction parallel to the surface of the fluorescent screen is less than or equal to 50 nm.

12. The fluorescent screen as described in claim 9, characterized in that, The average particle size of the phosphor particles is between 1 μm and 10 μm, and the average particle size of the oxide-filled particles is between 1 nm and 50 nm.

13. The fluorescent screen as described in claim 9, characterized in that, The main component of the filling oxide has a weight percentage greater than 99.9%; wherein, the main component of the filling oxide refers to the component with the highest proportion in the filling oxide.

14. The fluorescent screen as described in claim 13, characterized in that, The main components of the filler oxide are the same as those of the adhesive oxide, wherein the main components of the adhesive oxide refer to the components with the highest proportion in the adhesive oxide.

15. The fluorescent screen as described in claim 13, characterized in that, The main components of the filling oxide are SiO2 or Al2O3.

16. The fluorescent screen as described in claim 9, characterized in that, The fluorescent screen further includes a conductive layer disposed on the first structural layer, and the thickness of the conductive layer is between 50nm and 100nm.

17. The fluorescent screen as described in claim 9, characterized in that, The phosphor includes at least one of the following: RePO4:Z1, LaP5O 14 :Z1, CaSO4:Z1, SrSO4:Z1, NaYF4:Z1, LiYF4:Z1, KYF4:Z1, LiLaP4O 12 Z1, Y2(SO4)3:Z1, YAlO3:Z1, YF3:Z1; where Re represents one or more selected from Y, La, Lu, Sr, Gd, Sm, Ce, and Z1 represents a doping element, which contains one element selected from Nd, Pr, Bi.

18. The fluorescent screen as described in claim 9, characterized in that, The phosphor includes at least one of the following: RePO4:Z2, LaP5O 14 :Z2, CaSO4:Z2, SrSO4:Z2, NaYF4:Z2, LiYF4:Z2, KYF4:Z2, LiLaP4O 12 Z2, Y2(SO4)3:Z2, YAlO3:Z2, YF3:Z2; where Re represents one or more selected from Y, La, Lu, Sr, Gd, Sm, Ce, and Z2 represents a doping element containing two elements selected from Nd, Pr, and Bi.

19. An ultraviolet cathode ray tube, characterized in that, The ultraviolet cathode ray tube includes a fluorescent screen as described in any one of claims 9 to 18; The ultraviolet cathode ray tube also includes an electron gun, a tubular portion for housing the electron gun, and an electrical lead assembly electrically connected to the electron gun. The tubular portion is connected to the fluorescent screen portion; The electron gun is disposed inside the tubular portion and is used to emit an electron beam toward the fluorescent screen portion; The phosphor layer in the first structural layer disposed on the fluorescent screen emits light when excited by the electron beam; The electron gun is electrically connected to the outside via the electrical lead assembly.

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