Optical filter and camera module

Abstract

The optical filter comprises an optical filter base material, a light filtering surface and an anti-reflection surface are oppositely arranged on the optical filter base material, and a hydrophobic antifouling nano coating is arranged on the light filtering surface. According to the optical filter, the hydrophobic antifouling nano-coating is arranged on the filtering surface, the nano-coating is beneficial to improving the surface smoothness so as to reduce the adsorption force, and the camera module slightly moves or rotates, so that stains on the surface of the nano-coating can easily slide down and move to the dust catching glue between the optical filter and the support to be caught by the dust catching glue, and the dust catching glue is prevented from falling off. Therefore, stain imaging is prevented from affecting the photographing effect. The utility model further provides a camera module.

Description

Technical Field

[0001] The utility model relates to the technical field of the structural design of a camera module, in particular to a filter and a camera module. Background Art

[0002] A filter is an optical device used to select the required radiation band, which can adjust the light brightness to make the image clearer, change the color of the light, and reduce or eliminate the light emission, so as to obtain a clearer image, and is widely used in camera modules.

[0003] One of the long-existing pain points in the mobile phone camera module industry is that movable stains fall on the filter, and the adhesion between the stains and the filter is good, making it difficult for the stains to move, thus affecting the imaging and the photo-taking effect.

[0004] Currently, the method to solve the above problem is to draw dust-catching glue 11a between the filter 100a and the plastic bracket 10a, but this solution can only capture the stains that move onto the dust-catching glue, and the dust and stains in other positions cannot be captured by the dust-catching glue. Therefore, how to make the stains move easily and be captured by the dust-catching glue is the current bottleneck. In addition, as Figure 1 and Figure 2 shown, currently the screen printing layer 11b of the filter is on the filter surface, that is, on the IR coating layer. This solution causes part of the light to enter through the blank area of the screen printing layer, and after reflection and refraction, it reaches the chip to form stray light. Summary of the Utility Model

[0005] In view of this, the utility model provides a filter and a camera module. By setting a hydrophobic and anti-fouling nano-coating on the filter surface of the filter, the nano-coating helps to improve the surface smoothness and thus reduce the adsorption force. When the camera module moves or rotates slightly, the stains on the surface of the nano-coating can easily slide and move to the dust-catching glue between the filter and the bracket and be captured by it, thereby avoiding the stains imaging and affecting the photo-taking effect.

[0006] A filter includes a filter substrate, a filter surface and an anti-reflection surface are oppositely arranged on the filter substrate, and a hydrophobic and anti-fouling nano-coating is arranged on the filter surface.

[0007] In one embodiment, a screen printing layer is arranged on the anti-reflection surface.

[0008] In one embodiment, a dust-catching glue layer is arranged around the filter surface.

[0009] In one embodiment, the periphery of the filter is clamped to the bracket, and the dust-catching glue layer extends to the inner side of the bracket.

[0010] In one embodiment, an attaching glue layer is arranged on the anti-reflection surface, and the attaching glue layer is fixedly connected to the bracket.

[0011] In one embodiment, the filter further includes a black film, which is distributed around the light filtering surface and is used to absorb large-angle incident light incident on the edge of the lens. The black film includes an antireflection layer and an absorptive layer arranged in a stacked manner, and the absorptive layer is a black solid material layer.

[0012] In one embodiment, the black solid material layer is a metal material and / or metal oxide layer presenting black, and the transmittance of the absorptive layer is greater than 95%.

[0013] In one embodiment, the antireflection layer and the absorptive layer are respectively provided with multiple layers, and the antireflection layer and the absorptive layer are alternately stacked.

[0014] In one embodiment, the antireflection layer is formed by alternately stacking a high refractive index material layer and a low refractive index material layer.

[0015] An imaging module is configured with the filter as described above.

[0016] For the filter and the imaging module provided by the present utility model, by providing a hydrophobic and antifouling nano-coating on the light filtering surface of the filter, the nano-coating helps to improve the surface smoothness and thus reduce the adsorption force due to the special properties of its dense particles and surface structure. When the imaging module moves or rotates slightly, the stains on the surface of the nano-coating can easily slide and move to the dust-catching glue between the filter and the bracket and be captured by it, thereby avoiding the imaging of stains from affecting the photographing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present utility model, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative efforts.

[0018] Figure 1 Schematically shows the structure of an existing filter attached to a bracket.

[0019] Figure 2 Schematically shows the stray light path of an existing filter.

[0020] Figure 3 Schematically shows the structure of the filter of the embodiment of the present utility model attached to a bracket.

[0021] Figure 4 Schematically shows the stray light path of the filter of the embodiment of the present utility model.

[0022] Figure 5 Schematically shows the spin coating processing method of the nano-coating in the embodiment of the present utility model.

[0023] Figure 6 Schematically shows the front view structure of the filter of the embodiment of the present utility model.

[0024] Figure 7 Schematically shows the top view structure of the black film of the embodiment of the present utility model. Detailed implementation manners

[0025] The following will describe in detail specific embodiments of the present utility model in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all embodiments. Based on the description of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0026] In the description of the present utility model, unless otherwise clearly defined and limited, terms such as "arranged", "provided with", "disposed on", "installed", "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0027] The orientation or positional relationship indicated by terms such as "upper", "side part", "inner side" is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of this utility model is usually placed during use. It is only for the convenience of description and simplification of the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model.

[0028] The term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion. In addition to the listed elements, it may also include other elements not specifically listed.

[0029] As Figure 3 shown, the filter 100 of the embodiment of the present application includes a filter substrate 10. A filter surface 11 and an antireflection surface 12 are oppositely arranged on the filter substrate 10. A hydrophobic and antifouling nano-coating 13 is provided on the filter surface 11. In one embodiment, a silk screen layer 14 is provided on the antireflection surface 12. In one embodiment, a dust-catching glue layer 15 is provided around the filter surface 11. The periphery of the filter 100 is snap-connected to the bracket 200, and the dust-catching glue layer 15 extends to the inner side of the bracket 200. In one embodiment, an attaching glue layer 16 is provided on the antireflection surface 12, and the attaching glue layer 16 is fixedly connected to the bracket 200.

[0030] The filter 100 according to the embodiment of the present application is further coated with a hydrophobic and anti-fouling nano-coating 13 on the IR filter film after the IR filter film and the anti-reflection (AR) film are deposited, and a dust-catching adhesive layer 15 is sprayed between the filter 100 and the plastic bracket 200. For the stains that fall on the upper surface of the filter 100, such as the lens or the motor inside the camera module, the nano-coating 13 has a very high smoothness due to the special properties of its dense particles and surface structure, which helps to reduce the surface adsorption force. When the camera module moves or rotates slightly, the stains can easily slide and move on the surface of the filter film. When the stains move to the dust-catching adhesive layer, they are captured by it, thus avoiding the imaging of the stains.

[0031] Specifically, the filter 100 needs to be sprayed with a screen printing layer 14 to block unwanted light. The conventional screen printing layer 14 is sprayed on the IR filter surface 11 and has certain dimensional requirements. If it is screen-printed on the nano-coating 13, the stains are not easily moved to the dust-catching adhesive layer 15 when they move to the screen printing layer 14. Therefore, the screen printing layer 15 needs to be sprayed on the anti-reflection (AR) surface 12 of the filter to avoid affecting the anti-fouling effect of the nano-coating 13. As Figure 4 shown, from the path of the light, the light passes through the IR filter surface 11 and is refracted or reflected to the anti-reflection (AR) coating layer. Since the anti-reflection (AR) coating layer has a high transmittance and a low reflectance, the light will directly pass through the anti-reflection (AR) coating layer to the bottom screen printing layer 14 and be absorbed and blocked, thus avoiding the light from entering the chip and generating stray light. Therefore, setting the screen printing layer 14 on the anti-reflection (AR) surface 12 will block the stray light passing through the gap between the filter 100 and the plastic bracket 200 and the blank area of the screen printing layer, which avoids the problem of difficult movement of the stains on the screen printing layer 14 and also helps to improve the problem of stray light.

[0032] As Figure 5 shown, the nano-coating 13 is uniformly coated on the surface of the filter 100 by spin coating, which can assist in improving the surface quality of the IR filter surface 11 and improving the problems of film layer wrinkling and crystallization caused by high temperature, high humidity or salt spray reliability environment. The nano-coating 13 can be attached to the filter 100 by means of vapor deposition, various spraying, plating and other processing techniques. The material of the nano-coating 13 can be, but is not limited to, any one of cuprous oxide, silicon oxide, fluorocarbon coatings, etc., and its main function is hydrophobic and anti-fouling.

[0033] Specifically, the filter substrate 10 is first coated with an IR coating layer and an AR coating layer by evaporation coating method, then the screen printing layer 14 is printed on the AR coating layer by screen printing, and then, such as Figure 5The spin coating method shown coats a nano - coating 13 on the IR coating layer, and finally attaches it to a plastic bracket 200 through an adhesive layer 16 and coats a dust - trapping glue layer 16. When a stain drops onto the nano - coating 13, the stain can easily slide onto the dust - trapping glue layer 16 and be adhered to avoid imaging after slight movement or rotation.

[0034] As Figure 6 and Figure 7 shown, in one embodiment, the filter 100 further includes a black film 17. The black film 17 is distributed around the filter surface 11 and is used to absorb large - angle incident light incident on the edge of the lens. The black film 17 includes an anti - reflection layer 171 and an absorbing layer 172 arranged in layers. The absorbing layer 172 is a black solid material layer. In one embodiment, the black solid material layer is a metal material and / or metal oxide layer presenting black, and the transmittance of the absorbing layer is greater than 95%. In one embodiment, the anti - reflection layer 171 and the absorbing layer 172 are respectively provided with multiple layers, and the anti - reflection layer 171 and the absorbing layer 172 are alternately stacked. In one embodiment, the anti - reflection layer 171 is formed by alternately stacking a high - refractive - index material layer and a low - refractive - index material layer.

[0035] Specifically, the black film 17, as a light - shielding layer of the filter 100, is distributed on the filter (IR) surface of the filter body 100 to prevent large - angle light from incident on the gold wire surface connecting the image - sensing chip and the circuit board or the inner wall of the bracket and generating stray light. As Figure 7 shown, the black film 17 can be annularly distributed. For example, it can be a square ring (such as the hatched area in Figure 7 ) or other shapes, and is distributed in the edge area of the filter (IR) surface. In this way, the large - angle incident light incident on the edge of the lens can be incident on the black film 17 and be absorbed, and the small - angle incident light incident on the middle area 110 of the filter 100 can pass through the filter 100 normally and be imaged on the image sensor. The black solid material used for the absorbing layer 172 can be a metal material and / or metal oxide presenting black, and the transmittance can be greater than 95%. This is beneficial to reducing the reflectivity of the absorbing layer 172 itself at the material level. Moreover, since the absorbing layer 172 is a black solid material, the anti - reflection layer 171 and the absorbing layer 172 can be processed by the same coating process such as sputtering coating process, which is beneficial to improving the preparation efficiency of the black film 17 and thus the processing efficiency of the filter 100. Since there is both an anti - reflection layer 171 and a black absorbing layer 172, the black film 17 as a whole presents black, which not only has the visible - light absorption characteristic but also enables the black film 17 to achieve a lower reflectivity, thus improving the flare problem caused by the self - reflection light of the light - shielding layer and being beneficial to improving the imaging quality of the camera module.

[0036] Specifically, the filter 100 with the nano - coating 13 is mainly applied but not limited to devices such as mobile phone cameras, vehicle - mounted cameras, and smart wearable cameras.

[0037] Based on the same inventive concept as described above, the present application also provides an imaging module, which can be configured with a filter as in the foregoing embodiments. The imaging module includes a lens assembly and a circuit board assembly. The periphery of the filter 100 is snap - fitted onto the bracket 200. The lens assembly is bonded to the bracket 200. The lens assembly is located above the filter 100. The circuit board assembly is provided at the bottom end of the bracket 200. A chip is provided on the circuit board assembly, and the chip is located below the filter 100. Among them, the light in the external environment passes through the lens assembly and then reaches the filter 100 for light filtering to eliminate stray light, and then reaches the chip on the circuit board assembly. The chip converts the optical signal into an electrical signal to generate an image.

[0038] According to the above - mentioned embodiments, it can be seen that for the filter and the imaging module of the present utility model, by providing a hydrophobic and anti - fouling nano - coating on the light - filtering surface of the filter, the nano - coating helps to improve the surface smoothness and thus reduce the adsorption force due to the special properties of its dense particles and surface structure. When the imaging module moves or rotates slightly, the stains on the surface of the nano - coating can easily slide and move to the dust - trapping glue between the filter and the bracket and be captured by it, preventing the stains from adhering to the window area and affecting the imaging and photo - taking effect.

[0039] The above is only the specific implementation manner of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present utility model should be covered within the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be subject to the appended claims.

Claims

1. A filter, characterized in that, It includes a filter substrate and a black film for absorbing large-angle incident light incident on the edge of the lens. The filter substrate is provided with a filter surface and an antireflection surface oppositely. A hydrophobic and antifouling nano-coating is provided on the filter surface, and a silk-screen layer is provided on the antireflection surface. The black film includes a stacked antireflection layer and an absorption layer. The absorption layer is a black solid material layer, and the black film is distributed around the filter surface.

2. The optical filter according to claim 1, wherein A dust-catching adhesive layer is provided around the filter surface.

3. The optical filter according to claim 2, wherein, The periphery of the filter is snap-connected to a bracket, and the dust-catching adhesive layer extends to the inner side of the bracket.

4. The filter according to claim 3, characterized in that, An attaching glue layer is provided on the antireflection surface, and the attaching glue layer is fixedly connected to the bracket.

5. The filter according to claim 1, wherein The black solid material layer is a metal material and / or metal oxide layer presenting black, and the transmittance of the absorption layer is greater than 95%.

6. The optical filter according to claim 5, wherein, The antireflection layer and the absorption layer are respectively provided with multiple layers, and the antireflection layer and the absorption layer are alternately stacked.

7. The optical filter according to claim 6, characterized in that, The antireflection layer is formed by alternately stacking high-refractive-index material layers and low-refractive-index material layers.

8. An imaging module, characterized in that, A filter is configured as described in any one of claims 1 to 7.

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