Optical filter for solving silk screen deviation and manufacturing method thereof, lens, and camera assembly

Abstract

The application discloses a filter for solving silk printing deviation, a manufacturing method thereof, a lens and a camera assembly. The filter for solving silk printing deviation comprises a transparent substrate, a black frame ink layer formed by silk printing on a non-visible area of a first surface of the transparent substrate, an AR film plated on a second surface of the transparent substrate and an IR film plated on the first surface of the transparent substrate and covering the black frame ink layer. The black frame ink layer is formed by silk printing on the non-visible area of the first surface of the transparent substrate first, then the AR film (i.e. anti-reflection film) is plated on the second surface, and finally the IR film (i.e. infrared cut-off film) is plated on the first surface. In this way, the transparent substrate is very flat when no film is plated, silk printing is simple, silk printing deviation is easy to control, the filter is not easy to break, silk printing precision is high, and the problems of high silk printing deviation and high breakage rate in the prior art are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of infrared cut-off filter, in particular to a filter solving the deviation of silk printing, a manufacturing method thereof, a lens and a camera assembly. BACKGROUND

[0002] In the camera assembly, in order to solve the problem of color distortion, a red cut-off filter is generally installed on the light path of the image sensing element. The infrared cut-off filter is usually formed by coating a corresponding film layer on a transparent substrate, so as to prevent infrared rays from passing through, avoid the interference of the image sensing element to generate noise, and be beneficial to the restoration of color.

[0003] In order to achieve better shading effect, a layer of black frame ink is silk printed on the non-visible area of the red cut-off filter. For example, Chinese invention patent CN200510102000.3 discloses an aperture, which is a fixed aperture and is generally disc-shaped. The aperture includes a base, a film layer and a shading layer. The film layer is coated on the upper surface of the base and is formed on the surface of the base by a multi-layer coating process; the film layer can filter infrared rays or ultraviolet rays in the reflected light of the object, thereby improving the imaging quality of the digital camera. The shading layer is provided on the upper surface of the film layer and is composed of a light-blocking agent. The shading layer is only formed on the four surfaces of the film layer, thereby forming a light-transmitting area in the middle of the film layer. The light-transmitting area is generally circular and can allow light to pass through. The diameter of the light-transmitting area can be adjusted according to the required light quantity of the digital camera lens to control the light quantity.

[0004] Due to the difference in refractive index between the filter and the surrounding air, there will be light reflection. In order to help reduce reflection, a layer of anti-reflection film is added to the red cut-off filter in the industry. For example, Chinese invention patent CN201720004249.9 discloses an infrared cut-off filter, which includes a substrate composed of white glass and an infrared cut-off film layer plated on one surface of the white glass, a spin coating layer plated on the other surface of the white glass and an anti-reflection film layer plated on the spin coating layer; the spin coating layer includes a bottom layer and an absorption layer both composed of organic matter. The infrared cut-off film layer and the anti-reflection film layer are both plated by alternately depositing high refractive index material layers and low refractive index material layers, the high refractive index material layer can be composed of one of TiO2, Ti3O5, Ta2O5, H4 or several components; the low refractive index material layer can be composed of one of SiO2, MgF2 or two components.

[0005] In order to integrate the infrared cut-off filter with the light shielding and anti-reflection effects, the present inventors select the following manufacturing method: a transparent glass A surface is coated with an anti-reflection film, which is stacked by 5-9 layers of high and low refractive index materials, and the thickness is generally between 0.25-0.5 microns; then the transparent glass B surface is coated with an infrared cut-off film, which is stacked by 40-46 layers of high and low refractive index materials, and the thickness is generally between 5-6 microns; finally, a black border ink layer is silk-screened on the non-visible area of the B surface. However, during the specific implementation, the following technical problem is found: the thickness of the anti-reflection film is 0.25-0.5 microns, and the thickness of the infrared cut-off film on the other surface is 5-6 microns, the difference between the thicknesses is large, the stress of the two surfaces is seriously uneven during coating, and a serious bending phenomenon occurs. At this time, silk-screening the black border ink will cause the black border ink to deviate more and more from the center of the transparent glass, that is, the silk-screening deviation will become larger and larger, and when the transparent glass is bent too much, the silk-screening broken pieces problem is easily caused. SUMMARY

[0006] The present application aims to provide a filter and a manufacturing method thereof, a lens and a camera assembly for solving the silk-screening deviation, so as to solve the problems in the background art.

[0007] To achieve the above-mentioned purpose, the present application is implemented by the following technical solutions:

[0008] In a first aspect, the present application provides a filter for solving the silk-screening deviation, which comprises:

[0009] a transparent substrate;

[0010] a black border ink layer, which is silk-screened on the non-visible area of the first surface of the transparent substrate;

[0011] an AR film, which is coated on the second surface of the transparent substrate;

[0012] an IR film, which is coated on the first surface of the transparent substrate and covers the black border ink layer.

[0013] As a preferred embodiment of the filter for solving the silk-screening deviation provided by the present application, the AR film is coated by alternately depositing high refractive index material layers and low refractive index material layers, and the total number of layers is 5-9.

[0014] As a preferred embodiment of the filter for solving the silk-screening deviation provided by the present application, the thickness of the AR film is 0.25-0.5 microns.

[0015] As a preferred embodiment of the filter for solving the silk-screening deviation provided by the present application, the IR film is coated by alternately depositing high refractive index material layers and low refractive index material layers, and the total number of layers is 40-46.

[0016] As a preferred embodiment of the filter provided by the present application to solve the silk screen deviation, the thickness of the IR film is 5-6 microns.

[0017] As a preferred embodiment of the filter provided by the present application to solve the silk screen deviation, the material of the high refractive index material layer is one or several of TiO2, Ti3O5, ZrO2, Ta2O5, Nb2O5.

[0018] As a preferred embodiment of the filter provided by the present application to solve the silk screen deviation, the material of the low refractive index material layer is SiO2 or MgF2.

[0019] As a preferred embodiment of the filter provided by the present application to solve the silk screen deviation, the transparent substrate is transparent glass or transparent resin.

[0020] In the second aspect, a method for manufacturing a filter includes the following steps: providing a transparent substrate; forming a black border ink layer on the non-visible area of the first surface of the transparent substrate; then forming an AR film on the second surface of the transparent substrate; and finally forming an IR film on the first surface of the transparent substrate, wherein the IR film covers the black border ink layer.

[0021] As a preferred embodiment of the method for manufacturing a filter provided by the present application, the step of forming the IR film on the first surface of the transparent substrate specifically includes the following steps: forming a first layer on the first surface of the transparent substrate, with the thickness controlled at 10-50 nanometers; forming a second layer on the first layer by depositing a high refractive index material, with the thickness controlled at 10-30 nanometers; forming a third layer on the second layer by depositing a low refractive index material, with the thickness controlled at 20-60 nanometers; sequentially forming high-low refractive index material alternating layers as the fourth layer to the twenty-fourth layer on the third layer, wherein the thickness of each high refractive index material layer is controlled at 90-120 nanometers, and the thickness of each low refractive index material layer is controlled at 160-200 nanometers; sequentially forming high-low refractive index material alternating layers as the twenty-fifth layer to the Nth layer on the twenty-fourth layer, wherein N is 40-46, the thickness of each high refractive index material layer is controlled at 70-120 nanometers, the thickness of each low refractive index material layer is controlled at 100-200 nanometers, and the thickness of the last low refractive index material layer is controlled at 50-150 nanometers.

[0022] As a preferred embodiment of the method for manufacturing a filter provided by the present application, the material of the black border ink layer is epoxy resin, and the thickness is controlled at 5-15 microns.

[0023] In a third aspect, the present application provides a lens, which comprises a lens barrel, a lens arranged in the lens barrel, and a filter as described in any of the above or prepared by the method as described in any of the above, which is mounted on the light-in side of the lens barrel.

[0024] In a fourth aspect, the present application provides a camera assembly, which comprises a lens as described above, a support, a photosensitive chip, and a circuit board, wherein the circuit board is mounted on the lower end of the support, the lens is mounted on the upper end of the support, the photosensitive chip is arranged on the circuit board relative to the light path of the lens, and the photosensitive chip is electrically connected with the circuit board.

[0025] Compared with the prior art, the present application has the following advantages:

[0026] The filter provided by the present application solves the problem of printing deviation and high breakage rate in the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application and the background art, the drawings needed to be used in the description of the embodiments and the background art will be briefly introduced as follows. The drawings in the following description are only some embodiments of the present application or the background art, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0028] Figure 1 A schematic diagram of the filter for solving the problem of printing deviation of the present application;

[0029] Figure 2 An exploded schematic diagram of the filter for solving the problem of printing deviation of the present application;

[0030] Figure 3 A manufacturing flowchart of the filter for solving the problem of printing deviation of the present application;

[0031] Figure 4 A reflectivity simulation diagram of the filter, wherein curve A represents the reflectivity spectrum of the visible area of the filter of the present application, curve B represents the reflectivity spectrum of the non-visible area (i.e. the ink area) of the filter of the present application, and curve C represents the reflectivity spectrum of the visible area of the existing filter, wherein the existing filter refers to the filter obtained by first coating an IR film on a transparent substrate and then printing ink. DETAILED DESCRIPTION

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application. Any reference to "an embodiment" or "the embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. The appearances of the phrase "in one embodiment" or "in the embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily all directed to the same embodiment, nor are they necessarily all parallel embodiments of the same application.

[0033] As described in the background, the A surface of the transparent glass is coated with an anti-reflective film, which is stacked by 5-9 layers of high and low refractive index materials, and the thickness is generally between 0.25-0.5 microns; then the B surface of the transparent glass is coated with an infrared cut-off film, which is stacked by 40-46 layers of high and low refractive index materials, and the thickness is generally between 5-6 microns; finally, a layer of black border ink is silk-screened in the non-visible area of the B surface. However, in specific implementation, it is found that there are technical problems as follows: the thickness of the anti-reflective film is 0.25-0.5 microns, and the thickness of the infrared cut-off film on the other surface is 5-6 microns, the difference between the two thicknesses is large, and the stress of the two surfaces is seriously uneven during coating, which can cause serious bending. At this time, silk-screening black border ink can cause the black border ink to deviate more and more from the center of the transparent glass, that is, the silk-screening deviation will become larger and larger, and furthermore, when the transparent glass is bent greatly, it is easy to cause the problem of silk-screening breakage.

[0034] In order to solve the above technical problems, the present inventors propose a filter for solving silk-screening deviation.

[0035] Specifically, referring to Figures 1-3 , the filter for solving silk-screening deviation comprises:

[0036] a transparent substrate 1;

[0037] a black border ink layer 2, which is silk-screened in the non-visible area of the first surface 11 of the transparent substrate 1;

[0038] an AR film 3, which is coated on the second surface 12 of the transparent substrate 1;

[0039] an IR film 4, which is coated on the first surface 11 of the transparent substrate 1 and covers the black border ink layer 2.

[0040] The filter provided by the application solves the printing deviation, which comprises a transparent substrate 1, a black frame ink layer 2 formed on a first surface 11 of the transparent substrate 1 by printing, an AR film 3 formed on a second surface 12 of the transparent substrate 1 by plating, and an IR film 4 formed on the first surface 11 by plating. The transparent substrate 1 is flat when no film is plated, the printing is simple, the printing deviation is easy to control, the printing precision is high, and the problem of high printing deviation and high breakage rate in the prior art is solved.

[0041] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application.

[0042] Therefore, the following detailed description of the embodiments of the present application is not intended to limit the scope of the claimed application, but merely represents some embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0043] It should be noted that the embodiments in the present application and the features and technical solutions in the embodiments can be combined with each other without conflict.

[0044] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0045] Embodiment 1

[0046] Please refer to Figures 1-3 which shows a filter solving the printing deviation according to the present embodiment.

[0047] Specifically, the filter solving the printing deviation comprises a transparent substrate 1, a black frame ink layer 2 formed on a first surface 11 of the transparent substrate 1 by printing, an AR film 3 plated on a second surface 12 of the transparent glass by plating, and an IR film 4 plated on the first surface 11 of the transparent glass, wherein the IR film 4 covers the black frame ink layer 2.

[0048] The black frame ink layer 2 is located on the non-visible area of the first surface 11. It can be understood that the first surface 11 of the transparent substrate 1 is divided into a visible area and a non-visible area, and the non-visible area is arranged around the visible area, that is, the non-visible area can be understood as a ring-shaped edge area, so that a light-transmitting visible area, also called a window, is formed in the ring-shaped edge area. The material of the black frame ink layer 2 is black ink, which can absorb light and block the light incident on the edge of the filter from transmitting through the filter, so that the light incident on the visible area can transmit through the filter, thereby further improving the light shielding effect and improving the image quality.

[0049] Embodiment 2

[0050] Please refer to Figure 2 , which is a further optimization of the above-mentioned embodiment 1:

[0051] The AR film 3 is formed by alternately depositing and plating high-refractive-index material layers and low-refractive-index material layers. For example, the material of the high-refractive-index material layer can be selected from titanium oxide such as titanium dioxide or titanium trioxide, and the material of the low-refractive-index material layer can be selected from silicon dioxide. In order to improve the bonding stability of the AR film 3 and the transparent substrate 1, a silicon dioxide layer is preferably first formed on the transparent substrate 1, and then a titanium oxide layer is formed on the silicon dioxide layer. Preferably, the total number of layers is 5-9, and the thickness is preferably controlled to be 0.25-0.5 microns. In specific implementation, the thickness of each material layer and the number of layers can be set according to multiple tests. It should be noted that other suitable materials can also be used to form the AR film 3, which is not limited herein.

[0052] The IR film 4 is formed by alternately depositing and plating high-refractive-index material layers and low-refractive-index material layers. For example, the material of the high-refractive-index material layer can be selected from Ta2O5, ZrO2 or Nb2O5, and the material of the low-refractive-index material layer can be selected from silicon dioxide. In order to improve the bonding stability of the IR film 4 and the transparent substrate 1, a silicon dioxide layer is preferably first formed, and then a Ta2O5, ZrO2 or Nb2O5 layer is formed on the silicon dioxide layer. Preferably, the total number of layers is 40-46, and the thickness is preferably controlled to be 5-6 microns. In specific implementation, the thickness of each material layer and the number of layers can be set according to multiple tests. It should be noted that other suitable materials can also be used to form the IR film 4, which is not limited herein.

[0053] The transparent substrate 1 is transparent glass or transparent resin. In this embodiment, it is preferably transparent glass.

[0054] Embodiment 3

[0055] As Figure 3, which shows a method for manufacturing a filter according to this embodiment, comprising the following steps:

[0056] Providing a transparent substrate 1;

[0057] forming a black frame ink layer 2 on the non-visible area of ​​the first surface 11 of the transparent substrate 1;

[0058] Then, an AR film 3 is formed on the second surface 12 of the transparent substrate 1;

[0059] Finally, an IR film 4 is formed on the first surface 11 of the transparent substrate 1 , and the IR film 4 covers the black frame ink layer 2 .

[0060] When manufacturing, Figure 3 As shown, a black frame ink layer 2 is first formed by silk-screening on the non-visible area of ​​the first surface 11 of the transparent substrate 1, and then an AR film 3 (i.e., an anti-reflection film) is formed by coating the second surface 12. Finally, an IR film 4 (i.e., an infrared cut-off film) is further coated on the first surface 11, wherein the thickness of the IR film 4 is significantly thicker than that of the AR film 3. With this design, the transparent substrate 1 is very flat when not coated, silk-screen printing is simple, silk-screen deviation is easy to control, and it is not easy to break. The silk-screen printing precision is high, which solves the problems of silk-screen deviation and high fragmentation rate in the prior art.

[0061] In the prior art, the black frame ink layer is an ink layer, which is generally a conventional ink of an acrylic system and cannot withstand high temperatures. In the present invention, a high-temperature ink such as an epoxy resin system is used to form a black frame ink layer, and the thickness is controlled at 5 to 15 microns, but is not limited to this. In specific implementation, the inventors found that the use of high-temperature ink solves the problem of easy deformation due to heat to a certain extent. The subsequent use of conventional coating process (conventional coating process refers to the coating of alternating layers of high and low refractive index materials, with a total number of layers of 40 to 46 layers) has an impact on the optical performance, such as: different colors, spectral bands, poor consistency, etc.

[0062] The present invention's manufacturing method involves screen printing followed by coating, while simultaneously reducing the ink reflectivity. This requires consideration not only of the IR film's light filtering performance in the non-inked area (i.e., the visible region), but also of the IR film's reflectivity when deposited on the ink surface. To balance the optical performance of both the ink and non-inked areas, the inventors developed a coating method for the IR film after extensive experimentation.

[0063] Specifically, the step of forming an IR film on the first surface of the transparent substrate comprises the following steps:

[0064] (1) depositing a first layer on the first surface of the transparent substrate with a thickness controlled to be 10 to 50 nanometers;

[0065] (2) Plating high refractive index material on the first layer to form a second layer, thickness controlled at 10-30 nanometers;

[0066] (3) Plating low refractive index material on the second layer to form a third layer, thickness controlled at 20-60 nanometers;

[0067] (4) Plating high-low refractive index material alternately on the third layer to form the fourth layer to the twenty-fourth layer, wherein the thickness of each high refractive index material layer is controlled at 90-120 nanometers, and the thickness of each low refractive index material layer is controlled at 160-200 nanometers; plating high-low refractive index material alternately on the twenty-fourth layer to form the twenty-fifth layer to the Nth layer, N is 40-46, wherein the thickness of each high refractive index material layer is controlled at 70-120 nanometers, the thickness of each low refractive index material layer is controlled at 100-200 nanometers, and the thickness of the last low refractive index material layer is controlled at 50-150 nanometers.

[0068] The first layer to the third layer are thin layers, mainly to reduce the corrugation of thick layers. The fourth layer to the twenty-fourth layer are a first film stack, and the twenty-fifth layer to the Nth layer are a second film stack, the two film stacks are stacked together to achieve: high transmittance in the visible region (reduce reflectivity to 1.5% or less), infrared region cutoff, as shown in curves A, B in Figure 4 , not only making the optical performance of the visible region and the non-visible region close, but also making the reflectivity as low as possible, solving the problem that the reflectivity of the prior art after plating film and then silk printing can only be about 5% (as shown in curve C in Figure 4 ); at the same time, the transparent substrate of the manufacturing method of the present application is very flat when no film is plated, the silk printing is simple, the silk printing deviation is easy to control, and the substrate is not easy to break, the silk printing precision is high, solving the problems of high silk printing deviation and high breakage rate of the prior art.

[0069] Example 4

[0070] The present embodiment provides a lens, which comprises a lens barrel, a lens arranged in the lens barrel, and a filter as any of the above described filters mounted on the light entering side of the lens barrel. Thus, the camera assembly has all the features and beneficial effects of the filter described above for solving the silk printing deviation, which will not be repeated here.

[0071] Example 5

[0072] The present embodiment provides a camera assembly, which comprises the lens, a bracket, a photosensitive chip, and a circuit board, the circuit board is mounted on the lower end of the bracket, the lens is mounted on the upper end of the bracket, the photosensitive chip is arranged on the circuit board relative to the light path of the lens, and the photosensitive chip is electrically connected with the circuit board. Thus, the camera assembly has all the features and beneficial effects of the lens described above, which will not be repeated here.

[0073] Furthermore, the terms "first", "second", etc. are used herein for descriptive purposes only and are not to be construed as indicating or implying relative importance or an ordered sequence. Accordingly, features identified by "first", "second", etc. can include at least one of the features, explicitly or implicitly.

[0074] Obviously, the above-described embodiments are only some embodiments but not all embodiments of the present application, and the preferred embodiments of the present application are shown in the drawings, but do not limit the patent scope of the present application. The present application can be implemented in many different forms, and contrary to the foregoing embodiments, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing specific embodiments or make equivalent replacements to some technical features. Any equivalent structure made by using the content of the specification and drawings, directly or indirectly applied to other related technical fields, is also within the patent protection scope of the present application.

Claims

1. A method for manufacturing a filter that solves screen printing deviation, characterized in that: Filters include: a transparent substrate; a black frame ink layer, formed by silk-screening on the non-visible area of ​​the first surface of the transparent substrate; an AR film, which is coated on the second surface of the transparent substrate; an IR film, which is deposited on the first surface of the transparent substrate and covers the black frame ink layer; The manufacturing method of the optical filter comprises the following steps: providing a transparent substrate; forming a black border ink layer on the non-visible area of ​​the first surface of the transparent substrate; then coating an AR film on the second surface of the transparent substrate; and finally coating an IR film on the first surface of the transparent substrate, wherein the IR film covers the black border ink layer. The method of forming an IR film by coating on the first surface of the transparent substrate specifically comprises the following steps: coating a first layer on the first surface of the transparent substrate, with a thickness controlled within a range of 10 to 50 nanometers; coating a second layer of a high refractive index material on the first layer, with a thickness controlled within a range of 10 to 30 nanometers; coating a third layer of a low refractive index material on the second layer, with a thickness controlled within a range of 20 to 60 nanometers; sequentially coating alternating layers of high and low refractive index materials on the third layer as the fourth to twenty-fourth layers, wherein the thickness of each high refractive index material layer is controlled within a range of 90 to 120 nanometers, and the thickness of each low refractive index material layer is controlled within a range of 160 to 200 nanometers; sequentially coating alternating layers of high and low refractive index materials on the twenty-fourth layer as the twenty-fifth to Nth layers, where N is 40 to 46, wherein the thickness of each high refractive index material layer is controlled within a range of 70 to 120 nanometers, the thickness of each low refractive index material layer is controlled within a range of 100 to 200 nanometers, and the thickness of the last low refractive index material layer is controlled within a range of 50 to 150 nanometers; The material of the black frame ink layer is epoxy resin, and the thickness is controlled to be 5 to 15 microns.

2. The method for manufacturing a filter for solving screen printing deviation according to claim 1, characterized in that: The AR film is formed by alternately depositing high-refractive index material layers and low-refractive index material layers, with a total number of layers being 5-9.

3. The method for manufacturing a filter for solving screen printing deviation according to claim 2, characterized in that: The thickness of the AR film is 0.25-0.5 microns.

4. The method for manufacturing a filter for solving screen printing deviation according to claim 1, characterized in that: The IR film is formed by alternately depositing high-refractive index material layers and low-refractive index material layers, with a total number of 40-46 layers.

5. The method for manufacturing a filter for solving screen printing deviation according to claim 4, characterized in that: The thickness of the IR film is 5-6 microns.

6. A lens, characterized in that: The optical filter comprises a lens barrel, a lens arranged in the lens, and an optical filter manufactured by the manufacturing method of the optical filter according to any one of claims 1 to 5 and mounted on the light incident side of the lens barrel.

7. A camera assembly, characterized in that: It includes the lens, bracket, photosensitive chip and circuit board as described in claim 6, the circuit board is installed at the lower end of the bracket, the lens is installed at the upper end of the bracket, the photosensitive chip is arranged on the circuit board relative to the optical path of the lens, and the photosensitive chip is electrically connected to the circuit board.

Images