Polarization filter, camera and intelligent equipment

Abstract

The utility model discloses a polarization filter, a camera and intelligent equipment, and the polarization filter is characterized in that the polarization filter comprises a base material which is a transparent material; the wire grating is positioned on one side of the base material and is used for enabling light rays in a specific vibration direction to pass through; the coating film is located on the other side of the base material, is a multi-layer film and is used for allowing light rays with specific spectrums to pass through; the wire grating and the coating film are both in direct contact with the base material. According to the utility model, the integration of polarization and filtering functions is realized, the thickness is reduced, the number of devices and assembly procedures are reduced, and good product structure design matching performance and cost economy are achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to optical technology field, specifically, a kind of polarizing filter, camera and intelligent device. BACKGROUND

[0002] In face recognition equipment, palmprint palm vein recognition equipment, floor cleaning robot, laser radar and other technical applications, the projection end of emitting light and the receiving end of collecting image are usually included. To reduce the interference of ambient light, the light source of atmospheric window band is usually used in the emission end, and a narrow-band filter is built-in in the receiving end lens to filter the spectrum other than the light source of the emission end. In recent years, in the application with higher signal-to-noise ratio requirement, even polarized light is used as the light source of the emission end, and a polarizer is attached to the receiving end lens to filter the polarization of the received light.

[0003] The narrow-band filter in the industry at present is a mature application that can effectively filter the spectrum, but does not have the function of filtering the polarization state of light. To realize the polarization state filtering of light, an optical polarizer needs to be added externally to the product, or the optical polarizer is used after being attached to the filter. The process is relatively complex and increases the thickness. It often limits the product structure design and increases the cost.

[0004] The prior art at least has the following disadvantages:

[0005] 1. The traditional filter in the industry at present does not have the function of polarized light filtering.

[0006] 2. The polarizer in the industry at present does not have the function of narrow-band filtering.

[0007] 3. The process of integrating the filter and the polarizer is complex, which is prone to problems such as air bubbles and reduces the yield.

[0008] The disclosure of the above background technology content is only used to assist in understanding the inventive concept and technical scheme of the utility model, and it does not necessarily belong to the prior art of the present patent application. In the absence of explicit evidence that the above content has been disclosed on the filing date of the present patent application, the above background technology should not be used to evaluate the novelty and inventiveness of the present application. UTILITY MODEL CONTENT

[0009] Therefore, the utility model provides a polarized filter, which directly integrates gratings and coating on both sides of the substrate to realize the functions of narrow-band filtering and polarized filtering, integrates the functions of polarization and filtering, reduces the thickness, reduces the number of devices and assembly processes, and has good product structure design matching and cost economy.

[0010] In the first aspect, the utility model provides a polarized filter, characterized by comprising:

[0011] The substrate is a transparent material.

[0012] The wire grid is located on one side of the substrate and is used to pass light of a specific vibration direction.

[0013] The coating is located on the other side of the substrate and is a multilayer film used to pass light of a specific spectrum.

[0014] The wire grid and the coating are in direct contact with the substrate.

[0015] Optionally, the polarized filter is characterized in that the substrate is a material with uniform texture.

[0016] Optionally, the polarized filter is characterized in that the coating is an alternating stack of high-refractive-index and low-refractive-index compounds.

[0017] Optionally, the polarized filter is characterized in that the high-refractive-index film layer is made of any one or more of H2Si, Ti2O5, TiO2, and TiO3.

[0018] Optionally, the polarized filter is characterized in that the low-refractive-index film layer is made of any one or more of SiO2 and MF2.

[0019] Optionally, the polarized filter is characterized in that the thickness T of a single layer of the film and the central wavelength λ of the light passing through the film satisfy the relationship T = λ / 4*n, where n is the refractive index of the film material.

[0020] Optionally, the polarized filter is characterized in that the coating is integrated on the substrate by a coating process.

[0021] Optionally, the polarized filter is characterized in that the film in the coating has at least three refractive indices.

[0022] In a second aspect, the utility model provides a camera, characterized in that it comprises the polarized filter according to any one of the preceding aspects.

[0023] In a third aspect, the utility model provides an intelligent device, characterized in that it comprises the polarized filter according to any one of the preceding aspects.

[0024] Compared with the prior art, the utility model has the beneficial effects as follows:

[0025] The utility model directly integrates the wire grid and the coating on both sides of the substrate, realizes narrowband filtering and polarized filtering, integrates the functions of polarization and filtering, reduces the thickness, and reduces the number of devices and the assembly process, has good product structure design matching and cost economy, and can also improve the signal-to-noise ratio of the receiving end.

[0026] The linear grating and the coating film in the utility model directly contact with the base material, and also ensure high stability and reliability of the polarized filter, reduce loss caused by interface reflection or scattering, and improve light transmittance and filtering effect. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description, obviously, the drawings in the following description are only the embodiments of the utility model, and for the ordinary skilled in the art, other drawings can also be obtained according to the provided drawings without creative labor. Through reading the following detailed description of the non-limiting embodiments with reference to the drawings, other features, objects and advantages of the utility model will become more obvious:

[0028] Figure 1 It is a structural schematic diagram of a polarized filter in the embodiment of the utility model;

[0029] Figure 2 It is a linear grating function schematic diagram in the embodiment of the utility model;

[0030] Figure 3 It is a coating film function schematic diagram in the embodiment of the utility model.

[0031] 1-linear grating;

[0032] 2-base material;

[0033] 3-coating film;

[0034] 4-unpolarized light;

[0035] 5-receiving surface; DETAILED DESCRIPTION

[0036] The utility model will be explained in detail in combination with specific embodiments. The following embodiments will help the person skilled in the art to further understand the utility model, but do not limit the utility model in any form. It should be pointed out that for the ordinary skilled in the art, on the premise of not departing from the concept of the utility model, a number of modifications and improvements can be made. These all belong to the protection scope of the utility model.

[0037] The terms "first", "second", "third", "fourth" and the like in the description and claims of this utility model, and the above drawings, if any, are used for distinguishing similar objects and are not necessarily used to describe a particular sequential or chronological order. It is to be understood that the use of the terms so

[0038] The utility model discloses a kind of polarizing filters, to solve the problems in prior art.

[0039] The technical solutions of the utility model and how the technical solutions of the present application solve the above technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the utility model will be described below with reference to the drawings.

[0040] The utility model directly integrates grating and coating on both sides of the substrate, realizes narrowband filtering and polarizing filtering functions, integrates polarization and filtering functions, reduces thickness, reduces the number of devices and assembly processes, and has good product structure design matching and cost economy.

[0041] Figure 1 The structure of the polarizing filter is shown in the drawings. Figure 1 As shown in the drawings, the polarizing filter in the embodiment of the utility model comprises three layers of structure: substrate 2, wire grid 1 and coating 3.

[0042] The substrate 2 is a transparent material that allows light to pass through without significant absorption or scattering. The material of the substrate can be selected according to the application scenario, such as transparent glass, organic glass (PMMA), quartz, polycarbonate (PC), optical resin or other transparent materials not listed. The elastic modulus of the substrate is generally greater than 1 GPa. In this embodiment, the substrate 2 serves as the support structure of the polarizing filter, providing a stable attachment surface for the wire grid and the coating, and also ensuring that the light can pass through smoothly. In some embodiments, in order to make the overall thickness of the polarizing filter thinner, the thickness of the substrate 2 is between 0.1 and 1 mm.

[0043] Wire grid 1 is located on one side of substrate 2 for passing light of specific vibration direction. Wire grid 1 is made of aluminum, copper, silver or other unlisted metal materials. Wire grid is opaque material. Wire grid usually has high reflectivity. The period D of wire grid is about 1 / 10 of the wavelength of the filtered spectrum, in the range of 30nm≤D≤1200nm, such as 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1000nm, 1100nm or other unlisted values. The ratio of the width W of wire grid to the period D, defined as the duty cycle, is usually in the range of 0.2≤W / D≤0.8, such as 0.3, 0.4, 0.5, 0.6, 0.7 or other unlisted values. The ratio of the height H of wire grid to the width W, defined as the aspect ratio, is usually in the range of 0.5≤H / W≤5, such as 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5 or other unlisted values. The space between adjacent wire grids is filled with air or the same material as the substrate. The structure of wire grid is a series of parallel metal wires or grooves with specific shape, which can selectively reflect or absorb light of non-specific polarization direction.

[0044] Coating 3 is located on the other side of substrate 2 for passing light of specific spectrum. Coating 3 is transparent material. Coating 3 is a multilayer film, which is made of alternating layers of high and low refractive index compounds. The refractive index of high refractive index film layer is higher than that of low refractive index film layer. The material of high refractive index film layer can be any one or more of H2Si, Ti2O5, TiO2, TiO3, or other unlisted materials. The material of low refractive index film layer can be any one or more of SiO2, MF2, or other unlisted materials. The relationship between the single layer thickness T of the film and the transmission central wavelength λ is T = λ / 4*n, where n is the refractive index of the coating material. The function of the coating is to pass light of a specific spectral range and block or weaken light of other wavelengths. The function of the coating is achieved through material selection, thickness control and multilayer structure design of the coating. The coating is formed by evaporating the target material, accelerating it by magnetic field and sputtering it onto the substrate to form a thin film.

[0045] Wire grid 1 and coating 3 are located on opposite sides of substrate 2 and are in direct contact with substrate 2. As shown in FIG. 1, the wire grid 1 is located on the side of substrate 2 facing the light source 4, and the coating 3 is located on the side of substrate 2 facing the detector 5. The wire grid 1 is used to pass light of specific vibration direction, and the coating 3 is used to pass light of specific spectrum. The wire grid 1 and the coating 3 are in direct contact with the substrate 2. Figure 1As shown, the wire grid 1 is made on the upper surface of the substrate, and the plating film 3 is made on the lower surface of the substrate 2. In this embodiment, the wire grid and the plating film are directly made on the substrate, rather than being attached to the substrate through an additional article, i.e. without glue or other medium. This is also a prominent feature and core advantage of the utility model, which can greatly reduce the complexity of the process, reduce the thickness of the product, has very good cost economy, and is suitable for various application places. The wire grid is directly realized on the surface of the substrate through an etching process to realize the polarization filtering function. The plating film is integrated on the surface of the substrate through a plating process to realize the narrowband filtering function.

[0046] In some embodiments, the substrate is a material with uniform texture. The substrate is a material with uniform texture, i.e. all uniform and balanced components, such as transparent glass, organic glass (PMMA), polycarbonate (PC), optical resin or other transparent materials not listed. Taking the transparent glass as an example, the material of the polarization filter has three types: transparent glass, wire grid and plating film, without other additional materials.

[0047] In some embodiments, the wire grid is filled with air or the transparent material. When the wire grid is filled with air, the outside of the polarization filter is also air, which will not affect the propagation of light between the wire grids. When the wire grid is filled with transparent material, since the material is the same as the substrate, there is no refraction of light between the substrate and the wire grid gap, so that the processing of light remains stable. This embodiment makes the medium between the wire grids the same as the substrate or the external medium, reduces the interference of the light path during propagation, and improves the efficiency and stability of the light path processing.

[0048] In some embodiments, the plating film is a multilayer film, and the refractive index of each layer of the film is higher or lower than the film adjacent to the film. The refractive index of the multilayer film in the plating film is not the same, especially the refractive index of the adjacent film is different. Film A has two adjacent films B and C, and the refractive index of film A is the maximum or minimum refractive index of film A, film B and film C.

[0049] In some embodiments, the film in the plating film has at least three refractive indexes. For a multilayer film structure, by alternately depositing films with different refractive indexes on the substrate, a plating film with multiple refractive index characteristics can be formed. For example, a low refractive index film can be deposited on the substrate first, then a high refractive index film can be deposited, and so on, to form a multilayer structure. In this way, when light passes through the plating film, multiple reflections and refractions occur between different films, thereby exhibiting complex refractive index characteristics. Different films have different refractive indexes, so that the light can be processed more diversely to meet the needs of different application scenarios.

[0050] The wire grid 1 can filter light whose vibration direction is perpendicular to the wire grid and reflect light whose vibration direction is parallel to the wire grid. As shown in Figure 2 , after the unpolarized light 4 passes through the wire grid 1, only light whose vibration direction is perpendicular to the wire grid can reach the receiving surface 5.

[0051] As shown in Figure 3 , the coating 3 can filter the spectrum of the light by phase modulation of the light by the coating. Figure 3 NANOMETERS in the table is nanometer, referring to the wavelength of the light; PERCENT refers to the pass rate of the light. As shown in Figure 3 , the band-pass filtering effect of the coating with a wavelength range of 925nm-975nm is shown. Those skilled in the art can understand that the coating can be set to filter light of any wavelength range, which can be set according to the actual application requirements. Figure 3 The examples in the table are only used to illustrate the filtering effect, and are not a limitation on the protection scope of the present application. Any type of coating under the technical solution disclosed in the present application falls within the protection scope of the present application.

[0052] The present application also provides a camera comprising the polarizing filter according to any one of the preceding embodiments. The features of the camera will be significantly enhanced, especially in terms of light processing and image quality.

[0053] Since the polarizing filter can selectively allow light with a specific vibration direction (i.e., polarization direction) to pass through and can simultaneously filter out light outside a specific spectral range, the camera will be able to more accurately control the incidence of light when capturing images. This helps to reduce the interference of reflected light (such as the reflection of water surface, glass, and metal surface) on image quality, and improves the clarity and contrast of the image.

[0054] If the polarizing filter also has a spectral filtering function, it can help the camera more accurately restore the colors of the subject. By filtering out unwanted stray light such as ultraviolet light or other interfering light waves, the camera can more accurately capture and record the color information of the subject.

[0055] The polarizing filter can reduce the effect of scattered light, making the details in the image more clearly visible. This is particularly important for scenes such as landscapes and buildings that require details to be shown.

[0056] By reducing reflected light and scattered light, the polarizing filter can improve the contrast of the image, making the picture more vivid and three-dimensional.

[0057] In an outdoor environment with complex and variable light, the polarizing filter can reduce glare and reflections, making the captured photos clearer and more natural.

[0058] When shooting underwater, the reflection of light from the water surface and the object surface is particularly severe. Polarizing filters can effectively reduce these reflections, improving the clarity and color reproduction of underwater photos.

[0059] In macro photography, light scattering and reflection problems are particularly prominent. Polarizing filters can help reduce these adverse factors, making the macro photos taken more delicate and realistic.

[0060] Modern cameras usually support automatic or manual adjustment of the effect of the polarizing filter. Through the settings inside the camera or the external control ring, users can easily adjust the angle of the polarizing filter to achieve the best shooting effect. This convenience makes cameras containing polarizing filters more easy to operate and use.

[0061] The camera in this embodiment can be an RGB camera, an infrared camera, a depth camera, a laser radar, etc.

[0062] In summary, the camera in this embodiment will be significantly improved in terms of light processing capability, image quality optimization, application scenario expansion, and operation convenience.

[0063] The utility model also provides an intelligent device contains the polarizing filter of any preceding claim. The intelligent device will have a series of advanced functions related to light processing and image quality.

[0064] Because the polarizing filter can selectively allow light of a specific vibration direction and spectral range to pass through, this intelligent device will have higher flexibility and accuracy in visual processing. Whether it is taking photos, recording videos, or performing real-time image processing and analysis, the device can provide clearer, more accurate and vivid image information.

[0065] The presence of the polarizing filter enables the intelligent device to better adapt to different light environments. In strong light, it can reduce glare and reflections, improve image contrast and clarity; in weak light environments, it may work with other optical components to enhance light capture, reduce noise, and improve image quality.

[0066] Because the polarizing filter has spectral filtering function, this intelligent device will also perform well in color management. It can more accurately restore the colors of the photographed objects, reduce color deviation and distortion, and make the colors of the image more natural, rich and accurate.

[0067] The intelligent device containing the polarizing filter will be applicable to a variety of application scenarios, including but not limited to photography, videography, video calls, augmented reality (AR) and virtual reality (VR), etc. In these scenarios, the polarizing filter can play its unique role, improving user experience and satisfaction.

[0068] As part of the intelligent device, the polarization filter can be tightly integrated with other sensors, processors, and algorithms to form a complete image processing system. This system can automatically detect light conditions, adjust the angle and parameters of the filter, and optimize image processing algorithms to achieve the best image results.

[0069] Finally, the intelligent device containing the polarization filter will bring users a more high-quality, convenient and efficient visual experience. Whether it is to take professional photos, record high-definition videos, or conduct daily video calls and entertainment, users can feel the significant improvement in image quality and the intelligent advantage of light processing.

[0070] The intelligent device in this embodiment can be a face recognition device, a palmprint and palm vein recognition device, a sweeping robot, and other types of intelligent devices.

[0071] In summary, the intelligent device in this embodiment will exhibit excellent performance and advantages in visual processing, light adaptability, color management, application scenario diversity, and user experience. Such devices will become an important part of the future intelligent technology field, bringing users a more diverse visual experience and a more convenient lifestyle.

[0072] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. The above description of the disclosed embodiments enables a person skilled in the art to implement or use the present application. Various modifications to the embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application should not be limited to the embodiments shown herein, but should conform to the widest scope consistent with the principles and novel features disclosed herein.

[0073] The specific embodiments of the present application are described above. It should be understood that the present application is not limited to the above specific embodiments, and those skilled in the art can make various modifications or modifications within the scope of the claims, which does not affect the essential content of the present application.

Claims

1. A polarization filter, characterized by, The application relates to a polarized filter, comprising: a substrate made of transparent material; a wire grid on one side of the substrate for transmitting light of a specific vibration direction; a coating on the other side of the substrate, which is a multi-layer film for transmitting light of a specific spectrum; the wire grid and the coating are in direct contact with the substrate.

2. A polarization filter according to claim 1, characterized in that The substrate is made of material with uniform texture.

3. A polarization filter according to claim 1, characterized in that The coating is made of high-refractive-index and low-refractive-index compounds alternately stacked.

4. A polarization filter according to claim 1, characterized in that The high-refractive-index film layer is made of any one or more of H2Si, Ti2O5, TiO2 and TiO3.

5. A polarization filter according to claim 1, wherein The low-refractive-index film layer is made of any one or more of SiO2 and MF2.

6. A polarization filter according to claim 1, wherein The relationship between the single-layer thickness T of the film and the central wavelength lambda of transmission is T= lambda / 4*n, wherein n is the refractive index of the coating material.

7. A polarization filter according to claim 1, wherein The coating is integrated on the substrate by a coating process.

8. A polarization filter according to claim 1, wherein The film in the coating has at least three refractive indexes.

9. A camera characterized by, The application further relates to a polarized filter comprising the polarized filter according to any one of claims 1-8.

10. A smart device, comprising: The application further relates to a polarized filter comprising the polarized filter according to any one of claims 1-8.

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