Method for coating ink on edge of optical filter

Abstract

The invention provides a method for coating ink on the edge of an optical filter. The method comprises the following steps: (1) manufacturing a white sheet; (2) carrying out silk-screen printing, namely carrying out silk-screen printing on a plurality of small glass units on the surface of the white sheet by adopting a silk-screen printing process; (3) coating, namely coating an AR film on the front surface of the white sheet, cleaning, coating an IR film on the back surface of the white sheet, and finally cleaning; (4) plating an AF film; (5) coating a UV film; (6) cutting and expanding the film, namely cutting the coated glass, and expanding the film of the cut glass; (7) spraying ink on the glass subjected to film expansion by adopting an ink jet printer; (8) performing plasma cleaning, namely performing plasma cleaning on the surface of the glass by adopting vacuum plasma equipment, and removing an AF film on the surface of the glass at the same time; and (9) discharging the slices. The coating device is reasonable in conception, the vertical lifting edge of the optical filter can be efficiently coated to prevent stray light, and printing ink on the vertical lifting edge can be effectively prevented from adhering to the surface of a product.

Description

Technical Field

[0001] The invention relates to the technical field of film coating, and in particular to a method for ink coating on the edge of a filter. Background Art

[0002] A general camera system is mainly composed of a photosensitive chip, a filter, a lens, and other components. In this entire optical system, stray light has a great impact on image quality, and it is generally necessary to exhaust various methods to minimize the stray light generated by each component. Among them, the stray light generated by the edge of the filter (also called the vertical edge, that is, the side of the filter) sometimes needs to be eliminated as much as possible. Figure 1 As shown, the usual method is to apply ink to the four vertical sides of the filter, but the side of each filter needs to be ink-coated one by one, and each filter needs to be ink-coated 4 times, which is very inefficient; in addition, during the ink-coating process, the ink is also easy to stick to the surface, resulting in insufficient surface flatness.

[0003] To sum up, it is necessary to make further innovations on existing technologies. Summary of the invention

[0004] In view of the technical problems existing in the above-mentioned background technology, the present invention proposes a method for ink coating on the edge of a filter. The method has a reasonable design and can efficiently coat the vertical edge of the filter to prevent stray light, and can effectively prevent the ink on the vertical edge from sticking to the product surface. The spraying efficiency is high, the effect is good, and the product surface flatness is good.

[0005] In order to solve the above technical problems, the present invention provides a method for ink coating on the edge of a filter, which mainly comprises the following steps: (1) White film production Select block-shaped glass bricks, and then cut them into several glass pieces through wire cutting equipment, and then polish each glass piece through CNC equipment to obtain white pieces; (2) Silkscreen Use screen printing technology to print many "small glass units" on the surface of the white film; (3) AR film and IR film coating First, AR film is coated on the front of the white film, then it is cleaned, and then IR film is coated on the back of the white film, and then it is cleaned again; (4) AF coating The AF film, i.e. the hydrophobic film, is coated by a vacuum coating machine; (5) UV coating Use the fixture to position the coated glass sheet, and then stick the UV film on the glass sheet; (6) Cutting + film expansion Cut the coated glass, and then expand the cut glass; (7) Spraying ink Use an inkjet machine to spray ink on the expanded glass; (8) Plasma cleaning Use vacuum plasma equipment to plasma clean the glass surface and remove the AF film on the glass surface; (9) Film production The cut glass adhered to the UV film is irradiated with UV light. After the UV light irradiation, the adhesion between the glass and the UV film decreases, and the small glass unit can be taken out.

[0006] The method for inking the edge of the filter, wherein: the block glass bricks in the step (1) are made of fluorophosphate glass.

[0007] The method for inking the edge of the filter, wherein: the thickness of the white sheet in the step (1) is generally between 0.1-0.3 mm, and the size specification is 77*77*0.21.

[0008] The method for inking the edge of the filter, wherein: during the screen printing process of step (2), the screen mesh number is above 400 mesh, the tension is above 25N, the screen spacing is 1-5mm, the screen printing speed is 50-500mm / min, and the pressure is 0.1kgf-1kgf.

[0009] The method for coating ink on the edge of the optical filter, wherein: in the step (3), the AR film and the IR film are coated by using an electron beam with an energy of 5000W-8000W to penetrate into the coating material, and the coating material is evaporated by the electron beam and deposited on the surface of the white film; the coating temperature is between 120 and 180 degrees, and the vacuum degree at the beginning of the coating is between 1.0E-3 and 3.0E-3; during the coating process, the vacuum degree is between 1.5E-2 and 2.5E-2 when coating high refractive index materials, and the vacuum degree is between 1.0E-2 and 2.0E-2 when coating low refractive index materials.

[0010] The method for ink coating the edge of the filter, wherein: the specific method of coating the AR film on the front side of the white film 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 alternately coated with TiO2 and SiO2; The specific method of coating the IR film on the back of the white film in step (3) is as follows: the first layer is coated with MgF2 with a thickness of 10-30nm; the second layer to the last layer are alternately coated with TiO2 and SiO2.

[0011] The method for ink coating the edge of the filter, wherein: the thickness of the AR film is 300nm, and the entire coating time from vacuuming to coating to breaking the vacuum is 100-140 minutes; the thickness of the IR film is 5500nm, and the entire coating time from vacuuming to coating to breaking the vacuum is about 350-400 minutes.

[0012] The method for inking the edge of the filter, wherein the process of step (4) is as follows: placing a small container of steel wool containing a hydrophobic film in a vacuum coating chamber, with the bottom of the small container of steel wool in contact with a heating wire; when the coating chamber is evacuated to a vacuum degree below 5.0E-3, the heating wire is operated, and the steel wool on the heating wire is heated to evaporate the hydrophobic film, and the hydrophobic film is vaporized and deposited on the glass surface after coating in step (3).

[0013] The method for inking the edge of the filter, wherein: the outer sleeve of the clamp in step (5) is provided with an iron ring, and the outer circumferential surface of the iron ring is provided with "ears" for easy handling.

[0014] The method for ink coating the edge of the optical filter, wherein: the specific process of film expansion in step (6) is: (6.1) Place the iron ring with glass on top of the clamp of the film expansion device; (6.2) The clamp in the middle of the expansion device rises, and the film and glass expand accordingly; (6.3) Use a smaller iron ring to stick the expanded UV film; (6.4) Take down the expanded product. The expansion is successful and the size of the iron ring becomes smaller.

[0015] The method for ink coating the edge of the filter, wherein: the step (7) is to place the expanded glass flat on the stage, keep the nozzle of the inkjet machine in the vertical direction of the glass to spray the ink, the sprayed ink is sprayed onto the surface of the glass at a certain cone angle, and the ink viscosity is controlled within 100 cPa to ensure easy fluidity during spraying; according to the adhesion between the ink and the edge of the glass, at least one spraying is performed for 5 to 15 minutes.

[0016] The method for ink coating the edge of the filter, wherein the specific process of step (8) is: placing the product in a vacuum plasma chamber, evacuating the chamber to below 100 Pa, introducing oxygen and argon into the chamber, and applying voltage to form plasma, and then cleaning the glass surface to remove the AF film.

[0017] By adopting the above technical solution, the present invention has the following beneficial effects: The method for ink coating on the edge of the filter of the present invention is reasonably conceived, can efficiently coat the vertical edge of the filter to prevent stray light, and can effectively prevent the ink on the vertical edge from adhering to the product surface, has high spraying efficiency, good effect, and good product surface flatness.

[0018] The present invention also has the following characteristics: (1) the whole surface is AF, and after cutting, AF is only on the surface, and there is no AF on the vertical edge produced by cutting. At this time, ink is applied to the vertical edge, and the surface repels the ink due to the presence of AF; (2) if screen printing is performed after coating, the AF film-forming effect on the surface is not good due to the poor adhesion between AF and ink; therefore, the method of screen printing first and then coating is adopted, and the bonding effect between the last layer of SiO2 and AF is utilized to increase the adhesion of AF.

[0019] At the same time, the existing edge inking method is mainly edge ink coating, which generally uses an ink coating machine to ink the edges of the cut small unit glass one by one, which is very inefficient. For example, a 77*77 glass contains 200 small units, so it needs to be coated 200 times, coating 4 surfaces each time, while the present invention can be coated in one time, which is more efficient. In the existing edge inking method, ink coating often overflows black ink onto the glass surface; while the glass surface of the present invention has AF hydrophobic oil, which can block the ink overflowing onto the glass surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A schematic diagram of the process of a conventional filter edge ink coating method; Figure 2 (a)-(g) are schematic diagrams of products obtained in each process of the method for ink coating the edge of the optical filter of the present invention; Figure 3 A schematic diagram of manufacturing a white sheet involved in the method for ink coating the edge of an optical filter of the present invention; Figure 4 The product pattern after silk screen printing involved in the method for ink coating the edge of the optical filter of the present invention; Figure 5 The schematic diagram of the coating involved in the method of ink coating the edge of the optical filter of the present invention, in which 1-iron ring, 2-white sheet, 3-UV film, 4-ear; Figure 6 (a)-(d) are schematic diagrams of the film expansion process involved in the method of ink coating on the edge of the filter of the present invention. DETAILED DESCRIPTION

[0022] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] The present invention is further explained below in conjunction with specific implementation modes.

[0024] like Figure 2 As shown, the present embodiment provides a method for ink coating on the edge of a filter, which mainly includes the following steps: S100, white film production like Figure 3 As shown, a block of glass bricks is selected, and then cut into several glass pieces by wire cutting equipment, and then each glass block is polished by CNC equipment to obtain a white piece, such as Figure 2 (a) shows; the thickness of the white sheet is generally between 0.1-0.3 mm, and the size is 77*77*0.21; wherein, the block glass brick is fluorophosphate glass, which has a large absorption of infrared wavelengths and a certain transmittance to visible light.

[0025] S200, Silk screen The screen printing process is used to print many "small glass units" on the surface of the white film, such as Figure 2 (a) Figure 4 As shown; wherein, in the screen printing process, the mesh number of the screen is above 400 meshes, the tension is above 25N, the mesh spacing is 1-5mm, the screen printing speed is 50-500mm / min, and the pressure is 0.1kgf-1kgf.

[0026] S300, AR coating and IR coating First, AR film is coated on the front of the white film, and then IR film is coated on the back of the white film after cleaning. Figure 2(c) as shown, and then cleaned. The coating principle is as follows: the electron beam is injected into the coating material with a certain energy (5000W-8000W), and the 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 vacuum degree is between 1.0E-3~3.0E-3; during the coating process, when coating high refractive index materials, the vacuum degree is between 1.5E-2~2.5E-2; during the coating process, when coating low refractive index materials, the vacuum degree is between 1.0E-2~2.0E-2. The thickness of the AR film is about 300nm, and the entire coating time from vacuuming to coating to breaking the vacuum is 100-140 minutes (the optimal time is about 120 minutes); the thickness of the IR film is about 5500nm, and the entire coating time from vacuuming to coating to breaking the vacuum is 350-400 minutes (the optimal time is 360 minutes).

[0027] Among them, the specific process of coating AR film on the front of the white film is: the first layer is coated with MgF2, and the thickness is usually between 10-30nm. The main function is to increase the adhesion between the film and the glass substrate; the second layer to the last layer are alternately coated with TiO2 and SiO2, such as 7 layers of AR: MgF2 / TiO2 / SiO2 / TiO2 / SiO2 / TiO2 / SiO2.

[0028] The specific process of coating IR film on the back of the white film is: the first layer is coated with MgF2, the thickness is usually between 10-30nm, the main function is to increase the adhesion between the film and the glass substrate; the second layer to the last layer are alternately coated with TiO2 / SiO2; for example: MgF2 / TiO2 / SiO2 / TiO2 / SiO2 / TiO2 / SiO2 ....... TiO2 / SiO2.

[0029] S400, AF coating The AF film, i.e., the hydrophobic film, is coated by a vacuum coating machine. The hydrophobic film is a polymer material and is dropped into a small steel wool container. The small steel wool container containing the hydrophobic film is placed in a vacuum coating chamber, and the bottom of the small steel wool container is in contact with the heating wire. When the coating chamber is evacuated to a vacuum degree below 5.0E-3, the heating wire is operated, and the steel wool on the heating wire is heated to evaporate the hydrophobic film, and the hydrophobic film is vaporized and deposited on the glass surface after coating in the above step S300. Figure 2 (d) shown.

[0030] S500, UV coating like Figure 5As shown, the coated glass sheet is positioned by a fixture, and then the UV film is attached to the glass sheet; when attached, the glass and the film are tightly adhered together; after the UV film is irradiated with UV light, the adhesion is reduced to a very small level, and it can be easily removed. The outer sleeve of the fixture is provided with an iron ring, and the outer circumference of the iron ring is provided with "ears" for easy handling.

[0031] S600, cutting + film expansion like Figure 6 As shown, the coated glass is cut, and after cutting, each "small glass unit" is close to each other; then, the cut glass is expanded, and the specific process of expanding the film is as follows: S601, place the iron ring with glass on the clamp of the film expansion device, such as Figure 6 (a) as shown; S602, the clamp in the middle of the expansion device rises, and the film and glass expand accordingly. Figure 6 (b) as shown; S603, use a smaller iron ring to stick the expanded UV film, such as Figure 6 (c) as shown; S604, remove the expanded product, the expansion is successful, and the size of the iron ring becomes smaller, such as Figure 2 (e) Figure 6 (d) shown.

[0032] S700, spray ink Place the expanded glass flat on the stage, keep the inkjet nozzle in the vertical direction of the glass to spray the ink, and the sprayed ink is sprayed to the surface of the glass at a certain cone angle (5-10°). The surface repels the ink due to the presence of AF, and the ink flows to the vertical edge of the glass, where there is no AF, that is, the ink can adhere to the vertical edge. To ensure easy fluidity during spraying, the viscosity of the ink is controlled within 100cPa; depending on the adhesion between the ink and the edge of the glass, one or more sprayings can be done, and the time is between 5-15 minutes.

[0033] S800, plasma cleaning Use vacuum plasma equipment to perform plasma cleaning on the glass surface and remove the AF film on the glass surface; the specific process is: place the product in a vacuum plasma chamber, evacuate to below 100Pa, introduce oxygen (150-500SCCM) and argon into the chamber, and apply voltage (discharge power 100-1000W) to form plasma, clean the glass surface and remove the AF film.

[0034] S900, Film Output The cut glass adhered to the UV film is irradiated with UV light. After the UV light irradiation, the adhesion between the glass and the UV film decreases, and the small glass unit can be taken out.

[0035] The invention has a reasonable concept, can efficiently coat the vertical edge of the filter to prevent stray light, and can effectively prevent the ink of the vertical edge from adhering to the surface of the product.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for ink coating on the edge of a filter, characterized in that: The main steps include: (1) White film production Select block-shaped glass bricks, and then cut them into several glass pieces through wire cutting equipment, and then polish each glass piece through CNC equipment to obtain white pieces; (2) Silkscreen Use screen printing technology to print many "small glass units" on the surface of the white film; (3) AR film and IR film coating First, AR film is coated on the front of the white film, then it is cleaned, and then IR film is coated on the back of the white film, and then it is cleaned again; (4) AF coating The AF film, i.e. the hydrophobic film, is coated by a vacuum coating machine; (5) UV coating Use the fixture to position the coated glass sheet, and then stick the UV film on the glass sheet; (6) Cutting + film expansion Cut the coated glass, and then expand the cut glass; (7) Spraying ink Use an inkjet machine to spray ink on the expanded glass; (8) Plasma cleaning Use vacuum plasma equipment to perform plasma cleaning on the glass surface and remove the AF film on the glass surface; (9) Film production The cut glass adhered to the UV film is irradiated with UV light. After the UV light irradiation, the adhesion between the glass and the UV film decreases, and the small glass unit can be taken out.

2. The method for ink coating on the edge of a filter according to claim 1, characterized in that: In the screen printing process of step (2), the screen mesh number is above 400 mesh, the tension is above 25N, the screen spacing is 1-5mm, the screen printing speed is 50-500mm / min, and the pressure is 0.1kgf-1kgf.

3. The method for ink coating on the edge of a filter as claimed in claim 1, characterized in that : In the step (3), the AR film and the IR film are coated by using an electron beam with an energy of 5000W-8000W to penetrate into 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 and 180 degrees, and the vacuum degree at the beginning of the coating is between 1.0E-3 and 3.0E-3; during the coating process, the vacuum degree is between 1.5E-2 and 2.5E-2 when coating high refractive index materials, and the vacuum degree is between 1.0E-2 and 2.0E-2 when coating low refractive index materials.

4. The method for ink coating on the edge of a filter as claimed in claim 1, characterized in that : The specific method of coating the AR film on the front side of the white film in step (3) is as follows: the first layer is coated with MgF2 with a thickness of 10-30 nm; the second layer to the last layer are alternately coated with TiO2 and SiO2; The specific method of coating the IR film on the back of the white film in step (3) is as follows: the first layer is coated with MgF2 with a thickness of 10-30nm; the second layer to the last layer are alternately coated with TiO2 and SiO2.

5. The method for ink coating on the edge of a filter as claimed in claim 1, characterized in that: The thickness of the AR film is 300nm, and the entire coating time from vacuuming to coating to breaking the vacuum is 100-140 minutes; the thickness of the IR film is 5500nm, and the entire coating time from vacuuming to coating to breaking the vacuum is 350-400 minutes.

6. The method for ink coating on the edge of a filter according to claim 1, characterized in that: The process of step (4) is as follows: placing a small container of steel wool containing a hydrophobic film in a vacuum coating chamber, with the bottom of the small container of steel wool in contact with a heating wire; when the coating chamber is evacuated to a vacuum degree below 5.0E-3, the heating wire is operated, and the steel wool on the heating wire is heated to evaporate the hydrophobic film, and the hydrophobic film is vaporized and deposited on the glass surface after coating in step (3).

7. The method for ink coating on the edge of a filter as claimed in claim 1, characterized in that: The outer sleeve of the clamp in step (5) is provided with an iron ring, and the outer circumferential surface of the iron ring is provided with "ears" for easy carrying.

8. The method for ink coating on the edge of a filter as claimed in claim 1, characterized in that: The specific process of film expansion in step (6) is as follows: (6.1) Place the iron ring with glass on top of the clamp of the film expansion device; (6.2) The clamp in the middle of the expansion device rises, and the film and glass expand accordingly; (6.3) Use a smaller iron ring to stick the expanded UV film; (6.4) Take down the expanded product. The expansion is successful and the size of the iron ring becomes smaller.

9. The method for ink coating on the edge of a filter as claimed in claim 1, characterized in that: The step (7) is to place the expanded glass flat on a stage, keep the nozzle of the inkjet machine in the vertical direction of the glass and spray the ink, the ink is sprayed onto the surface of the glass at a certain cone angle, and the ink viscosity is controlled within 100 cPa to ensure easy fluidity during spraying; according to the adhesion between the ink and the edge of the glass, spraying is performed at least once, the time is 5 to 15 minutes.

10. The method for ink coating on the edge of a filter according to claim 1, characterized in that: The specific process of step (8) is as follows: placing the product in a vacuum plasma chamber, evacuating the chamber to below 100 Pa, introducing oxygen and argon into the chamber, applying voltage to form plasma, and then cleaning the glass surface to remove the AF film.

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