A method of edge coating an optical filter

Abstract

The application provides a method for coating ink on the edge of a filter, which comprises the following steps: (1) white sheet making; (2) screen printing, that is, printing a plurality of small glass units on the surface of the white sheet by using a screen printing process; (3) film plating, that is, plating an AR film on the front surface of the white sheet, cleaning, then plating an IR film on the back surface of the white sheet, and finally cleaning; (4) AF film plating; (5) UV film covering; (6) cutting and film expanding, that is, cutting the glass after the film covering, and then expanding the film of the cut glass; (7) spraying ink on the expanded film of the glass by using an inkjet machine; (8) plasma cleaning, that is, cleaning the surface of the glass by using a vacuum plasma device, and removing the AF film on the surface of the glass; and (9) sheet outputting. The application has reasonable design, can efficiently coat the straight-up edge of the filter to prevent stray light, and can effectively prevent the ink on the straight-up edge from adhering to the surface of the product.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coating, in particular to a method for coating the edges of a light filter. BACKGROUND

[0002] A general camera system is mainly composed of a photosensitive chip, a light filter, a lens and other components. In this entire optical system, stray light has a great influence on image quality, and various methods are generally required to reduce the stray light generated by each component as much as possible. Among them, the stray light generated by the edges of the light filter (also known as the straight-up edge, i.e. the side edge of the light filter) also needs to be eliminated as much as possible. As shown in FIG. 1, the usual method is to perform ink coating on the four straight-up edges of the light filter, but each light filter needs to be coated on the side, and each light filter needs to be coated 4 times, which is very slow. In addition, during the ink coating process, the ink is also easy to stick to the surface, resulting in insufficient surface flatness. Figure 1

[0003] In view of the above, it is necessary to further innovate the prior art. SUMMARY

[0004] In view of the technical problems in the above background art, the present application provides a method for coating the edges of a light filter, which is reasonable in concept, can efficiently coat the straight-up edges of the light filter to prevent stray light, and can effectively prevent the ink on the straight-up edges from sticking to the surface of the product, has high spraying efficiency, good effect, and good surface flatness of the product.

[0005] To solve the above technical problems, the present application provides a method for coating the edges of a light filter, which mainly comprises the following steps:

[0006] (1) White sheet making

[0007] Select a block-shaped glass brick, then cut it into a plurality of glass sheets by a wire cutting device, and then polish each glass block by a CNC device to obtain a white sheet;

[0008] (2) Silk printing

[0009] A plurality of "small glass units" are silk printed on the surface of the white sheet by a silk screen printing process;

[0010] (3) AR film and IR film plating

[0011] AR film is plated on the front surface of the white sheet, then cleaned, and then IR film is plated on the back surface of the white sheet, and finally cleaned;

[0012] (4) AF film plating

[0013] AF film, i.e. hydrophobic film, is plated by a vacuum coating machine;

[0014] (5) UV film covering ​

[0015] The glass sheet on which the film is completed is positioned by the clamp, and then the UV film is attached to the glass sheet;

[0016] (6) Cutting + film expansion

[0017] The film-coated glass is cut, and then the cut glass is expanded;

[0018] (7) Ink spraying

[0019] The ink is sprayed on the expanded glass by using an inkjet machine;

[0020] (8) Plasma cleaning

[0021] The surface of the glass is cleaned by using a vacuum plasma device, and the AF film on the surface of the glass is removed;

[0022] (9) Sheet output

[0023] The cut glass adhered to the UV film is irradiated by UV light, and after the UV light irradiation, the adhesion between the glass and the UV film decreases, so that the small glass unit can be taken out.

[0024] The method for coating the edges of the filter with ink, wherein: the block-shaped glass bricks in step (1) are fluorophosphate glass.

[0025] The method for coating the edges of the filter with ink, wherein: the thickness of the white sheet in step (1) is generally between 0.1-0.3mm, and the size specification is 77*77*0.21.

[0026] The method for coating the edges of the filter with ink, wherein: the screen printing process in step (2) has a mesh number of more than 400 meshes, a tension of more than 25N, a screen distance of 1-5mm, a silk printing speed of 50-500mm / min, and a pressure of 0.1kgf-1kgf.

[0027] The method for coating the edges of the filter with ink, wherein: in step (3), the AR film and the IR film are coated by using an electron beam with an energy of 5000W-8000W to hit the coating material, and the coating material is evaporated by the electron beam and deposited on the surface of the white sheet; the coating temperature is between 120~180 degrees, and the opening coating vacuum degree is between 1.0E-3~3.0E-3; during the coating process, the vacuum degree is between 1.5E-2~2.5E-2 when coating high refractive index material, and the vacuum degree is between 1.0E-2~2.0E-2 when coating low refractive index material.

[0028] The method for coating the edges of the filter with ink, wherein: the specific way of coating AR film on the front surface of the white sheet in step (3) is: the first layer is coated with MgF2 with a thickness of 10~30nm; the second layer to the last layer are coated with TiO2 and SiO2 alternately.

[0029] The specific method of the step (3) is that the first layer is coated with MgF2 with a thickness of 10-30 nm, and the second layer to the last layer are alternately coated with TiO2 and SiO2.

[0030] The method for coating the edge of the filter with ink, wherein the thickness of the AR film is 300 nm, the whole coating time is 100-140 minutes from the beginning of vacuumizing to the breaking of vacuum, and the thickness of the IR film is 5500 nm, the whole coating time is about 350-400 minutes from the beginning of vacuumizing to the breaking of vacuum.

[0031] The method for coating the edge of the filter with ink, wherein the process of the step (4) is that a small container of steel wool with hydrophobic film is placed in the vacuum coating cavity, and the small container of steel wool is in contact with the heating wire below; when the coating cavity is vacuumized to below 5.0E-3 vacuum degree, the heating wire is worked, the hydrophobic film is evaporated after the steel wool above the heating wire is heated, and the hydrophobic film is vaporized and deposited on the glass surface after the step (3) of coating.

[0032] The method for coating the edge of the filter with ink, wherein the outer part of the clamp in the step (5) is provided with an iron ring, and the outer circumferential surface of the iron ring is provided with "ears" for facilitating carrying.

[0033] The method for coating the edge of the filter with ink, wherein the specific process of the step (6) is that:

[0034] (6.1) the iron ring with glass is placed above the clamp of the film expanding equipment;

[0035] (6.2) the clamp in the middle of the film expanding equipment is raised, and the film and the glass are expanded;

[0036] (6.3) the expanded UV film is stuck with a smaller iron ring;

[0037] (6.4) the expanded product is taken out, the expansion is successful, and the size of the iron ring is also smaller.

[0038] The method for coating the edge of the filter with ink, wherein the step (7) is that the expanded glass is placed flat on the object table, the nozzle of the inkjet machine is kept in the vertical direction of the glass to spray ink, the sprayed ink is sprayed to the surface of the glass at a certain conical angle, the viscosity of the ink is controlled within 100 cPa to ensure the easy flowability of the spraying, and at least one spraying is performed according to the adhesion of the ink and the edge of the glass, and the time is 5-15 minutes.

[0039] The method for coating the filter edge ink, wherein the specific process of the step (8) is: placing the product in a vacuum plasma cavity, vacuumizing to below 100 Pa, introducing oxygen and argon into the cavity, applying voltage to form plasma, and then cleaning the glass surface to remove the AF film.

[0040] By adopting the technical scheme, the present application has the following beneficial effects:

[0041] The method for coating the filter edge ink has reasonable conception, can efficiently coat the straight-up edge of the filter to prevent stray light, and can effectively prevent the ink of the straight-up edge from adhering to the product surface, has high spraying efficiency, good effect, and good flatness of the product surface.

[0042] The present application also has the following features: (1) the whole surface is AF, the AF is only on the surface after cutting, and the straight-up edge generated by cutting has no AF, at this time, the surface repels the ink when the straight-up edge is coated with ink; (2) if silk printing is performed after coating, the adhesion between the AF and the ink is not good, and the film forming effect of the surface AF is not good; therefore, the method of silk printing first and then coating is adopted, the adhesion of the AF is increased by using the bonding effect of the last layer of SiO2 and the AF.

[0043] Meanwhile, the existing edge ink coating method mainly coats the edge, generally uses an ink coating machine to coat the edge of the small unit glass cut out one by one, and the efficiency is very low, for example, for 77*77 glass containing 200 small units, 200 times of coating are required, and each time 4 surfaces are coated, while the present application can be coated at one time, and the efficiency is higher. In the existing edge ink coating method, the ink often overflows to the glass surface, while the present application can block the ink overflowing to the glass surface by the AF hydrophobic oil on the glass surface. BRIEF DESCRIPTION OF DRAWINGS

[0044] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the following specific embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0045] Figure 1 It is a flowchart of the traditional filter edge ink coating method;

[0046] Figure 2 (a)-(g) are schematic diagrams of products obtained in each flow of the method for coating the filter edge ink of the present application;

[0047] Figure 3 It is a schematic diagram of white sheet making involved in the method for coating the filter edge ink of the present application;

[0048] Figure 4 The product pattern after silk printing involved in the method for coating the edges of the filter according to the present application;

[0049] Figure 5 The film covering diagram involved in the method for coating the edges of the filter according to the present application, wherein, 1-iron ring, 2-white sheet, 3-UV film, 4-ear;

[0050] Figure 6 (a)-(d) are the film expanding process diagrams involved in the method for coating the edges of the filter according to the present application. DETAILED DESCRIPTION

[0051] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0052] The present application will be further explained and described below in conjunction with specific embodiments.

[0053] As shown in Figure 2 , the method for coating the edges of the filter according to the present application mainly includes the following steps:

[0054] S100, white sheet making

[0055] As shown in Figure 3 , select a block-shaped glass brick, then cut it into a plurality of glass sheets through a wire cutting device, and then polish each glass block through a CNC device to obtain a white sheet, as shown in Figure 2 (a). The thickness of the white sheet is generally between 0.1-0.3mm, and the size specification is 77*77*0.21; wherein, the block-shaped glass brick is a fluorophosphate glass, which has a great absorption to infrared wavelength and a certain transmittance to visible light.

[0056] S200, silk printing

[0057] A plurality of "small glass units" are silk printed on the surface of the white sheet by using a silk screen printing process, as shown in Figure 2 (a), Figure 4 ; wherein, the mesh number in the silk screen printing process is above 400 meshes, the tension is above 25N, the mesh spacing is 1-5mm, the silk printing speed is 50-500mm / min, and the pressure is 0.1kgf-1kgf.

[0058] S300, AR film and IR film plating

[0059] First, AR film is plated on the front of the white sheet, and then IR film is plated on the back of the white sheet after cleaning, as shown in Figure 2 (c) and finally cleaning. The plating principle is that the electron beam with a certain energy (5000W-8000W) is shot into the plating material, and the material is evaporated by the electron beam and deposited on the surface of the white sheet; the plating temperature is between 120-180 degrees, and the opening plating vacuum degree is between 1.0E-3-3.0E-3; during the plating process, when plating high refractive index material, the vacuum degree is between 1.5E-2-2.5E-2; during the plating process, when plating low refractive index material, the vacuum degree is between 1.0E-2-2.0E-2. The thickness of the AR film is about 300nm, and the whole plating time is 100-140 minutes (the best time is about 120 minutes) from vacuum extraction to plating to vacuum breaking; the thickness of the IR film is about 5500nm, and the whole plating time is 350-400 minutes (the best time is 360 minutes) from vacuum extraction to plating to vacuum breaking.

[0060] The specific process of plating AR film on the front of the white sheet is as follows: the first layer is plated with MgF2, the thickness is usually between 10-30nm, and the main function is to increase the adhesion of the film and the glass substrate; the second layer to the last layer is plated with TiO2 and SiO2 alternately, for example, 7 layers of AR: MgF2 / TiO2 / SiO2 / TiO2 / SiO2 / TiO2 / SiO2.

[0061] The specific process of plating IR film on the back of the white sheet is as follows: the first layer is plated with MgF2, the thickness is usually between 10-30nm, and the main function is to increase the adhesion of the film and the glass substrate; the second layer to the last layer is plated with TiO2 / SiO2 alternately, for example: MgF2 / TiO2 / SiO2 / TiO2 / SiO2 / TiO2 / SiO2....... TiO2 / SiO2.

[0062] S400, plating AF film

[0063] AF film, i.e. hydrophobic film, is plated by vacuum plating machine, which is a kind of high polymer material dropped into a small steel wool container; the small steel wool container containing the hydrophobic film is placed in the vacuum plating cavity, and the bottom of the small steel wool container is in contact with the heating wire; when the plating cavity is vacuumed to below 5.0E-3 vacuum degree, the heating wire is worked, and the steel wool above the heating wire is heated to evaporate the hydrophobic film, and the hydrophobic film is vaporized and deposited on the glass surface plated in the above step S300, as shown in Figure 2 (d).

[0064] S500, covering UV film

[0065] As shown in Figure 5As shown, a clamp is used to position the coated glass sheet, and then the UV film is adhered to the glass sheet. During application, the glass and the film are tightly bonded together. After being irradiated with UV light, the adhesion of the UV film is reduced to a very small value, allowing it to be easily removed. The clamp is fitted with an iron ring, and the outer circumference of the iron ring has "ears" for easy handling.

[0066] S600, cutting + film expansion

[0067] like Figure 6 As shown, the coated glass is cut, and after cutting, each "small glass unit" is placed close together; then, the cut glass is expanded, and the specific process of expanding the coating is as follows:

[0068] S601. Place the iron ring with glass on top of the clamp of the film expansion equipment, such as... Figure 6 As shown in (a);

[0069] S602, the clamp in the middle of the expansion device rises, and the film and glass expand accordingly, such as Figure 6 As shown in (b);

[0070] S603, Use smaller iron rings to adhere the expanded UV film, such as... Figure 6 As shown in (c);

[0071] S604. Remove the product after mold expansion. Mold expansion was successful, and the size of the iron ring has also decreased. Figure 2 (e) Figure 6 As shown in (d).

[0072] S700, spray ink

[0073] Place the expanded glass flat on the stage. Hold the printhead of the Inkjet inkjet printer vertically to the glass and spray ink. The ink is sprayed at a tapered angle (5-10°) onto the glass surface. Due to the presence of AF (airfoil), the surface repels the ink, allowing it to flow to the vertical edge of the glass. Since there is no AF on the vertical edge, the ink can adhere to it. To ensure easy flowability, the ink viscosity should be controlled below 100 cPa. Depending on the adhesion between the ink and the glass edge, one or more coats can be applied, with a spraying time between 5-15 minutes.

[0074] S800, plasma cleaning

[0075] The glass surface is cleaned using a vacuum plasma device, which also removes the AF film. The specific process is as follows: the product is placed in a vacuum plasma chamber, the vacuum is evacuated to below 100Pa, oxygen (150-500SCCM) and argon are introduced into the chamber, and a voltage (discharge power 100-1000W) is applied to form plasma, which cleans the glass surface and removes the AF film.

[0076] S900, the sheet is taken out

[0077] The cut glass adhered to the UV film is irradiated with UV light, and the adhesion between the glass and the UV film decreases after UV light irradiation, so that the small glass unit can be taken out.

[0078] The present application is reasonable in concept, can efficiently coat the straight rising edge of the filter to prevent stray light, and can effectively prevent the ink of the straight rising edge from sticking to the surface of the product.

[0079] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method of filter edge inking, characterized by, The method comprises the following steps: (1) White sheet making Selecting block-shaped glass bricks, cutting the glass bricks into a plurality of glass sheets through a wire cutting device, and polishing the glass sheets through a CNC device to obtain white sheets; (2) Silk printing A plurality of "small glass units" are silk printed on the surface of the white sheets through a silk screen printing process; (3) AR film and IR film plating AR film is plated on the front surface of the white sheet, the white sheet is cleaned, IR film is plated on the back surface of the white sheet, and the white sheet is cleaned again; (4) AF film plating AF film, i.e. hydrophobic film, is plated through a vacuum plating machine; (5) UV film covering The glass sheet on which the film is plated is positioned through a clamp, and then the UV film is attached to the glass sheet; (6) Cutting and film expanding The glass sheet on which the film is attached is cut, and then the cut glass sheet is subjected to film expanding; (7) Ink spraying The glass sheet on which the film is expanded is sprayed with ink through an inkjet machine; (8) Plasma cleaning The surface of the glass sheet is subjected to plasma cleaning through a vacuum plasma device, and the AF film on the surface of the glass sheet is removed; (9) Sheet outputting The cut glass sheet adhered to the UV film is subjected to UV irradiation, the adhesion between the glass sheet and the UV film is reduced after the UV irradiation, and the small glass unit can be taken out.

2. The method of filter edge inking as claimed in claim 1, wherein: In the silk printing process of step (2), the screen mesh is above 400 meshes, the tension is above 25 N, the screen distance is 1-5 mm, the silk printing speed is 50-500 mm / min, and the pressure is 0.1 kgf-1 kgf.

3. The method of edge coating an optical filter of claim 1, wherein In step (3), the AR film and the IR film are plated by using an electron beam with an energy of 5000 W-8000 W to hit the film plating material, the film plating material is evaporated by the electron beam and then deposited on the surface of the white sheet; the plating temperature is between 120-180 degrees, the opening plating vacuum degree is between 1.0E-3-3.0E-3, during the plating process, the vacuum degree is between 1.5E-2-2.5E-2 when plating high refractive index material, and the vacuum degree is between 1.0E-2-2.0E-2 when plating low refractive index material.

4. The method of edge coating an optical filter of claim 1, wherein In step (3), the specific way of plating AR film on the front surface of the white sheet is as follows: the first layer is plated with MgF2, and the thickness is 10-30 nm; the second layer to the last layer are plated with TiO2 and SiO2 alternately. In step (3), the specific way of plating IR film on the back surface of the white sheet is as follows: the first layer is plated with MgF2, and the thickness is 10-30 nm; the second layer to the last layer are plated with TiO2 and SiO2 alternately.

5. The method of filter edge inking as claimed in claim 1, wherein: The thickness of the AR film is 300 nm, the whole plating time is 100-140 minutes from vacuum extraction to film plating to vacuum breaking; the thickness of the IR film is 5500 nm, the whole plating time is 350-400 minutes from vacuum extraction to film plating to vacuum breaking.

6. The method of filter edge inking as recited in claim 1, wherein, In step (4), a small container of steel wool containing the hydrophobic film is placed in the vacuum plating cavity, the small container of steel wool is in contact with the heating wire, and the steel wool on the heating wire is heated to evaporate the hydrophobic film, and the evaporated hydrophobic film is deposited on the surface of the glass sheet plated in step (3).

7. The method of filter edge inking as claimed in claim 1, wherein: The clamp in step (5) is externally sleeved with an iron ring, and the outer circumferential surface of the iron ring is provided with "ears" for convenient carrying.

8. The method of coating the edges of optical filters of claim 1, wherein: The specific process of the film expanding in step (6) is as follows: (6.1) Place the iron ring with glass on the clamp of the film expanding device; (6.2) Raise the clamp in the middle of the film expanding device, and the film and glass are expanded; (6.3) Use a smaller iron ring to stick the expanded UV film; (6.4) Take off the expanded product, and the film expanding is successful. The size of the iron ring is also smaller.

9. The method of coating the edges of optical filters of claim 1, wherein: Step (7) is to place the expanded glass on the object table, keep the nozzle of the inkjet machine in the vertical direction of the glass, spray the ink, and the sprayed ink is sprayed to the surface of the glass at a certain conical angle. The viscosity of the ink is controlled within 100 cP to ensure the easy flowability of the spraying. According to the adhesion of the ink and the edge of the glass, at least one spraying is performed, and the time is 5-15 minutes.

10. The method of filter edge inking as defined in claim 1, wherein, The specific process of step (8) is as follows: place the product in a vacuum plasma cavity, vacuumize to below 100 Pa, introduce oxygen and argon into the cavity, apply voltage to form plasma, and then clean the surface of the glass to remove the AF film.

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