Polarization shaping sheet, camera and intelligent equipment

Abstract

The utility model discloses a polarization shaping sheet, a camera and intelligent equipment, and the polarization shaping sheet is characterized in that the polarization shaping sheet comprises a substrate 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 microstructure is positioned on the other side of the base material and is used for changing a light path; the wire grating and the microstructure are positioned on opposite sides of the base material and are in direct contact with the base material. According to the utility model, the integration of polarization and light path processing functions is realized, the thickness is reduced, the number of devices and the assembly process are reduced, and good product structure design matching performance and cost economy are achieved.

Description

Technical Field

[0001] This utility model relates to the field of optical technology, specifically to a polarization shaping plate, a camera, and a smart device. Background Technology

[0002] In applications such as facial recognition devices, palm print and vein recognition devices, robotic vacuum cleaners, and LiDAR, there is typically a projection end that emits light and a receiving end that acquires images. In applications requiring a high signal-to-noise ratio, polarized light is usually used as the light source for the transmitter, and a polarizer is attached to the lens of the receiver to filter the polarization of the received light.

[0003] In existing products, multiple optical elements are often used to process the light path so that the light is projected at the required emission angle. Current technology often uses one or more lenses to process the light path. However, this approach is complex, bulky, and costly, with complicated assembly processes leading to high manufacturing costs.

[0004] The above background information is provided only to aid in understanding the inventive concept and technical solution of this utility model. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above information was disclosed on the filing date of this patent application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Utility Model Content

[0005] To address this, this invention proposes a polarization shaping sheet that directly integrates gratings and microstructures on both sides of a substrate, enabling optical path processing and polarization filtering functions. This integration of polarization and optical path processing functions reduces thickness, decreases the number of components and assembly steps, and provides better product structure design matching and cost-effectiveness.

[0006] In a first aspect, this utility model provides a polarization shaping sheet, characterized in that it comprises:

[0007] The substrate is a transparent material;

[0008] A wire grid, located on one side of the substrate, is used to allow light rays in a specific vibration direction to pass through;

[0009] The microstructure, located on the other side of the substrate, is used to alter the optical path;

[0010] The wire grid and the microstructure are located on opposite sides of the substrate and are in direct contact with the substrate.

[0011] Optionally, the polarization shaping sheet is characterized in that the substrate is a material with uniform texture.

[0012] Optionally, the polarizing sheet is characterized in that the substrate contains a diffusion structure to make the light uniform.

[0013] Optionally, the polarization shaping sheet is characterized in that the microstructure is a microlens array.

[0014] Optionally, the polarization shaping sheet is characterized in that the microstructure compensates for the polarization loss introduced by the wire grid, thereby improving the overall polarization shaping effect.

[0015] Optionally, the polarization shaping sheet is characterized in that the duty cycle W / D of the wire grid is between [0.2, 0.8].

[0016] Optionally, the polarizing shaping sheet is characterized in that the aspect ratio H / W of the wire grid is between [0.5, 5].

[0017] Optionally, the polarizing shaping sheet is characterized in that the spaces between the wire grids are filled with air or the transparent material.

[0018] Secondly, the present invention provides a camera, characterized in that it includes the polarization shaping sheet described in any of the preceding claims.

[0019] Thirdly, this utility model provides an intelligent device, characterized in that it includes the polarization shaping sheet described in any of the preceding claims.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] This invention directly integrates gratings and microstructures on both sides of the substrate to achieve optical path processing and polarization filtering functions. It integrates polarization and optical path processing functions, reduces thickness, reduces the number of components and assembly steps, and has good product structure design matching and cost economy. At the same time, it can improve the signal-to-noise ratio of the receiver.

[0022] In this invention, both the centerline grid and the microstructure are in direct contact with the substrate, which also ensures the high stability and reliability of the polarization shaping sheet, reduces the loss caused by interface reflection or scattering, and improves the light transmittance and filtering effect. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort. Other features, objects, and advantages of this utility model will become more apparent by reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0024] Figure 1 This is a schematic diagram of the structure of a polarization shaping sheet in an embodiment of this utility model;

[0025] Figure 2 This is a schematic diagram of a wire grid function in an embodiment of the present utility model.

[0026] 1-Wire grid;

[0027] 2-Substrate;

[0028] 3-Microstructure;

[0029] 4-Unpolarized light;

[0030] 5-Receiving surface; Detailed Implementation

[0031] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0032] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the utility model described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0033] This utility model provides a polarization shaping sheet, which aims to solve the problems existing in the prior art.

[0034] The technical solutions of this utility model and this application solve the above-mentioned technical problems in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this utility model will now be described with reference to the accompanying drawings.

[0035] This invention directly integrates gratings and microstructures on both sides of the substrate to achieve optical path processing and polarization filtering functions. It integrates polarization and optical path processing functions, reduces thickness, reduces the number of components and assembly processes, and has good product structure design matching and cost economy.

[0036] Figure 1 This is a schematic diagram of the structure of a polarization shaping sheet according to an embodiment of the present invention. Figure 1 As shown, in this embodiment of the present invention, a polarization shaping sheet contains a three-layer structure: a substrate 2, a wire grid 1, and a microstructure 3.

[0037] Substrate 2 is a transparent material that allows light to pass through without significant absorption. The material of the substrate can be selected based on the application, such as transparent glass, PMMA (polymethyl methacrylate), quartz, polycarbonate (PC), optical resin, or other unlisted transparent materials. The elastic modulus of the substrate is generally greater than 1 GPa. In this embodiment, substrate 2 serves as the supporting structure for the polarizing shaper, providing a stable adhesion surface for the wire grid and microstructure while ensuring smooth light transmission. In some embodiments, to achieve a thinner overall thickness for the polarizing shaper, the thickness of substrate 2 is between 0.1 and 1 mm.

[0038] A wire grid 1 is located on one side of the substrate 2 and is used to allow light with a specific vibration direction to pass through. The wire grid 1 is made of aluminum, copper, silver, or other unlisted metals. The wire grid is opaque. The wire grid typically has high reflectivity. The period D of the wire grid is approximately on the order of 1 / 10 of the wavelength of the filtered spectrum, within 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 any other unlisted value. The ratio of the wire grid width W to the period D is defined as the duty cycle, and typically takes the range of 0.2 ≤ W / D ≤ 0.8, such as 0.3, 0.4, 0.5, 0.6, 0.7, or any other unlisted value. The ratio of the height H to the width W of a wire grid is defined as the aspect ratio, which is typically 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 any other unlisted value. Adjacent wire grids are filled with air or the same material as the substrate. The structure of a wire grid consists of a series of parallel metal lines or grooves with a specific shape, capable of selectively reflecting or absorbing light with non-specific polarization directions.

[0039] Microstructure 3, located on the other side of substrate 2, is used to alter the optical path. The microstructure is situated on the opposite side of the substrate, opposite the wire grid. Microstructures exhibit a variety of morphologies, commonly including microlens arrays and diffraction grating structures. Taking a microlens array as an example, it consists of a large number of regularly arranged tiny lens units, each ranging in size from tens to hundreds of micrometers. These microlens units can be fabricated on the substrate surface using semiconductor processing techniques such as photolithography and etching, allowing for precise control over their shape and size.

[0040] The primary function of microstructures is to alter the optical path. In the case of a microlens array, the principle is based on the refraction of a lens. When light strikes a microlens, it is refracted according to the lens's optical properties, causing originally parallel or diverging light rays to converge or diverge according to a certain pattern, thus changing the direction and distribution of light propagation. For microstructures like diffraction gratings, the principle of light diffraction is utilized. When light strikes the grating, diffracted light is generated in different directions. By designing the grating's period and structural parameters, the direction and intensity distribution of the diffracted light can be precisely controlled, thereby adjusting the optical path.

[0041] The ability of microstructures to alter the optical path allows polarization shapers to meet the needs of various optical systems. In some imaging systems, microlens arrays can focus light onto the photosensitive unit of a detector, improving light collection efficiency and image quality. In optical communication, diffraction grating microstructures can be used for beam splitting, combining, or wavelength selection of optical signals, enabling efficient transmission and processing. Furthermore, the synergistic effect of microstructures and wire gratings further expands the application range of polarization shapers in complex optical systems. For example, in some advanced optical sensors, they can achieve precise control over the polarization state and propagation path of light to obtain richer optical information.

[0042] In some embodiments, the substrate is a homogeneous material. A homogeneous material means that the substrate consists entirely of uniform and balanced components, such as transparent glass, PMMA (polymethyl methacrylate), polycarbonate (PC), optical resin, or other unlisted transparent materials. Taking transparent glass as an example, the polarizing film has three materials: transparent glass, wire mesh, and microstructure, without any other additional materials.

[0043] In some embodiments, the substrate includes a diffusion structure to ensure uniform light distribution. The diffusion structure, embedded within the substrate, can take the form of tiny particles, fibers, microlens arrays, or carefully designed surface roughness. The size, shape, and distribution of these structures are meticulously designed to achieve optimal light diffusion. The primary function of the diffusion structure is to ensure uniform distribution of light passing through the substrate. When light enters the substrate and encounters these structures, it is scattered or refracted, causing a slight change in the direction of light propagation. This change disperses light that might have been concentrated in a particular area over a larger area, thus achieving uniform light distribution. In some optical systems, especially when using lasers or high-brightness light sources, a spotting effect can easily occur, where light becomes excessively concentrated in a specific area, resulting in excessive brightness. The diffusion structure effectively reduces this effect, making the light distribution more uniform and improving image clarity and visual comfort. This embodiment combines the diffusion structure with polarization shaping functionality. The polarization shaping sheet not only enables polarization selection of light but also ensures a more uniform distribution of light after it passes through. This helps reduce problems such as light intensity fluctuations and uneven spot distribution in optical systems, improving overall optical performance. In this embodiment, the wire grid is responsible for selecting light rays with specific vibration directions to pass through, while the diffusion structure ensures that these transmitted rays are uniformly distributed during subsequent propagation. The two work together to achieve polarization shaping and homogenization of the light. Although the microstructure is primarily responsible for altering the optical path, the homogenization effect of the diffusion structure also helps improve the optical performance of the microstructure. For example, in scenarios where it is necessary to adjust the direction of light while maintaining a uniform light distribution, the synergistic effect of the diffusion structure and the microstructure is particularly important.

[0044] In some embodiments, the spaces between the wire grids are filled with air or the transparent material. When air is filled between the wire grids, the area outside the polarizing shaper is also air, which eliminates any additional interference to the propagation of light between the wire grids. When transparent material is filled between the wire grids, since it is made of the same material as the substrate, there is no refraction or other changes in the light path at the gap between the substrate and the wire grids, thus keeping the light processing stable. This embodiment makes the medium between the wire grids the same as the substrate or the external medium, reducing interference to the light path during propagation and improving the efficiency and stability of the light path processing.

[0045] In some embodiments, the microstructure compensates for the polarization loss introduced by the wire grid, thereby improving the overall polarization shaping effect. When a wire grid selectively transmits light of a specific polarization, polarization loss is unavoidable. For light components whose electric field vector is parallel to the direction of the wire grid lines, the metal wire or anisotropic material will absorb or reflect them. For example, when a wire grid is made of metal wire, the electric field of parallel polarized light induces a current within the metal wire. The thermal effect of this current causes light energy to be lost as heat, which is absorption loss. Simultaneously, some parallel polarized light is reflected by the surface of the metal wire and cannot pass through the wire grid, forming reflection loss. These losses reduce the intensity of the final output specific polarized light, affecting the polarization shaping effect.

[0046] Because the actual fabricated wire grids are not ideal, factors such as the roughness of the lines, slight inhomogeneities in the spacing, and the imperfect optical properties of the materials all contribute to a less than ideal selective transmission of polarized light. For example, the roughness of the lines causes light to scatter on their surface, scattering some of the parallel polarized light that should have been absorbed or reflected in other directions. Some of this scattering may even mix with the transmitted vertically polarized light, reducing the polarization purity of the outgoing light, which is also a form of polarization loss.

[0047] If the microstructure is a microlens array, it can compensate for polarization loss by changing the direction of light propagation. When light passes through a grating, the intensity distribution and propagation direction change due to polarization loss. A microlens array can refocus or guide some light rays that have deviated from their original propagation direction due to reflection or scattering by the grating, allowing them to participate in subsequent optical processes, effectively increasing the effective luminous flux. For example, for light rays scattered in all directions due to grating reflection, microlenses can refocus a portion of them onto a direction closer to the main optical path, thus compensating to some extent for the intensity loss caused by reflection.

[0048] If the microstructure is a diffraction grating microstructure, it compensates for polarization loss by addressing the differences in diffraction characteristics of light with different polarizations. When light passes through the grating, it carries information related to polarization loss (such as changes in intensity distribution). The diffraction grating, based on its period and structural parameters, produces specific diffraction for light with different angles and polarization states. For the light component lost due to the polarization selection of the grating, appropriate diffraction grating parameters can be designed to cause constructive interference in a specific direction. For example, a specific polarization component that would normally be weakened by absorption and reflection from the grating can be enhanced by interference with other diffracted light in a certain direction through the action of the diffraction grating, thereby increasing the intensity of light in that polarization direction, compensating for polarization loss, and improving the overall polarization purity and intensity.

[0049] By compensating for polarization loss through microstructures, the intrusion of non-target polarized light is reduced, making the final output light closer to ideal linearly polarized light and improving polarization purity. For example, in some optical experiments with extremely high requirements for polarization purity, such as high-precision polarization interferometry, microstructure compensation can effectively reduce background noise and improve measurement accuracy and reliability.

[0050] Microstructures can compensate for polarization losses and adjust the propagation path of light, resulting in a more uniform light intensity distribution. For example, microlens arrays can redistribute areas of uneven light intensity that may exist after passing through a grid, making the overall light beam more uniform. In the display field, this helps improve the brightness uniformity of liquid crystal displays, making images clearer and softer, and enhancing the visual experience.

[0051] In summary, the microstructure's compensation for polarization loss enables the polarization shaper to achieve a better balance in polarization selection, light intensity maintenance, and optical path adjustment, thus optimizing overall optical performance. In numerous fields such as optical communication, optical imaging, and laser processing, this optimized polarization shaper can better meet the stringent requirements of systems for light polarization and propagation characteristics, improving the performance and reliability of the entire optical system.

[0052] This invention also provides a camera that includes the polarizing film described in any of the preceding claims. The innovative design of this camera significantly improves its optical performance and image quality.

[0053] In cameras, polarizing filters are cleverly embedded into the camera's optical system, typically located somewhere within the lens assembly, to polarize and adjust the light path before it enters the camera sensor. The specific integration method may vary depending on the camera model and design, but in any case, it is essential to ensure that the polarizing filter is stably fixed inside the camera and that its optical performance remains unaffected during use.

[0054] By utilizing the polarization selectivity of polarizing filters, cameras can more effectively control the polarization state of light entering the lens. This helps reduce adverse factors such as reflected light and glare, improving image contrast and sharpness. If the polarizing filter contains a diffusion structure, the camera can also achieve a more uniform distribution of light during shooting. This helps reduce issues such as flare and uneven brightness in the image, resulting in a more natural and balanced picture. Polarizing filters can also improve color reproduction to some extent. By optimizing the polarization state and light path distribution, cameras can more accurately capture and reproduce the true colors of the subject.

[0055] This embodiment integrates a polarizing filter into the camera, a novel and practical design. It not only improves the camera's optical performance but also expands its application scenarios and shooting effects.

[0056] The camera in this embodiment can be any type of measurement device such as an RGB camera, an infrared camera, a depth camera, or a LiDAR.

[0057] This invention also provides an intelligent device that includes the polarization shaping sheet described in any of the preceding claims. This intelligent device not only enhances the visual performance of the device but may also play an important role in multiple application scenarios.

[0058] Polarizing filters are cleverly designed and integrated into display modules, camera modules, or other components of smart devices that require optical processing. The specific integration method varies depending on the type of smart device and its design requirements, but the core purpose is to optimize light processing using the properties of the polarizing filter as light enters or leaves the device.

[0059] For smart devices equipped with displays, polarizing filters can improve display quality, enhance color saturation, contrast, and viewing angles, thereby providing users with a clearer and more realistic visual experience.

[0060] Integrating a polarizing filter into the camera module can effectively reduce adverse factors such as reflected light and glare, improving the clarity and color reproduction of captured images. This is especially important for applications such as taking photos and making video calls.

[0061] In outdoor or complex lighting environments, polarizing filters can reduce the interference of ambient light on equipment, improving the equipment's anti-interference ability and stability.

[0062] When the smart device is a smartphone, a smartphone with an integrated polarization shaping plate can provide better photo and display performance, meeting users' needs for high-quality images and visual experiences.

[0063] When the smart device is a tablet, integrating a polarizing screen protector into the tablet can improve the viewing experience of its display and make it more comfortable for users during extended use.

[0064] When smart devices are wearable devices, the application of polarization shaping sheets can further improve the display and interaction performance of wearable devices such as AR / VR glasses and smartwatches.

[0065] When smart devices are professional equipment, integrating polarizing filters into professional equipment such as cameras and camcorders can meet the stringent requirements of professional photographers and videographers for light control and image quality.

[0066] The smart device in this embodiment can also be a face recognition device, a palm print and palm vein recognition device, a robot vacuum cleaner, or other types of smart devices.

[0067] This embodiment integrates a polarization shaping film into a smart device, representing an innovative and practical design approach. It not only enhances the device's visual performance and image quality but also plays a crucial role in various application scenarios.

[0068] The various embodiments described in this specification are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The above description of the disclosed embodiments enables those skilled in the art to implement or use this invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this invention. Therefore, this invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0069] The specific embodiments of this utility model have been described above. It should be understood that this utility model is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the substantive content of this utility model.

Claims

1. A polarization-shaping plate, characterized by, Comprising: a substrate, which is a transparent material; a wire grid on one side of the substrate for passing light of a specific vibration direction; a microstructure on the other side of the substrate for changing the light path; the wire grid and the microstructure are on opposite sides of the substrate and are in direct contact with the substrate.

2. A polarization-shaping plate according to claim 1, characterized in that the substrate is a material with uniform texture.

3. A polarization-shaping plate according to claim 1, characterized in that the substrate contains diffusion structures to make the light uniform.

4. A polarization-shaping plate according to claim 1, characterized in that the microstructure is a microlens array.

5. A polarization-shaping plate according to claim 1, characterized in that the microstructure compensates for the polarization loss introduced by the wire grid, thereby improving the overall polarization shaping effect.

6. A polarization-shaping plate according to claim 1, characterized in that the duty cycle W / D of the wire grid is between [0.2, 0.8].

7. A polarization-shaping plate according to claim 1, characterized in that the aspect ratio H / W of the wire grid is between [0.5, 5].

8. A polarization-shaping plate according to claim 1, characterized in that the wire grid is filled with air or the transparent material.

9. A camera characterized by, a polarization shaping sheet according to any one of claims 1-8.

10. A smart device, comprising: a polarization shaping sheet according to any one of claims 1-8.

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