2781 results about "Polarizer" patented technology

The invention discloses an egg surface microcrack detection system and method based on image analysis, and relates to the field of surface defect nondestructive detection.The method comprises the steps that a process identification interface module obtains a processing process identifier of an egg in real time; the multi-angle annular light source module is provided with a multi-band annular light source array comprising visible light and near-infrared LED lamp beads which are independently controlled, a polaroid group and a beam splitter prism are integrated, and visible light polarization images and near-infrared polarization images on the surfaces of the eggs are synchronously collected; the thermal excitation enhancement unit obtains a thermal infrared image; the process filtering module extracts the axial elongation of the mechanical stress microcrack after graded transportation, and calculates the mesh fractal dimension of the thermal stress microcrack after UV disinfection; the multi-modal feature fusion module generates a dual-channel crack probability graph; and the dynamic feedback control module outputs a micro-crack risk grade and adjusts the rotating speed of the objective table and the light source intensity. The method has the advantages that accurate judgment of mechanical and thermal stress cracks is realized, and curved surface reflection interference is broken through.

The invention discloses a magnetic material defect detection system based on image recognition, which adopts a first acquisition module, a first determination module, a second determination module, a second acquisition module and a third acquisition module, and is characterized in that the first acquisition module is used for performing multi-angle illumination control on the surface of a magnetic material by adopting a polarized light imaging device; mirror reflection generated by the strong light reflection characteristic is inhibited by adjusting the angle of a polaroid and the incident angle of a light source, original image data with uniform illumination distribution are obtained, and if it is detected that an overexposure area exists in an image, exposure parameters and the polarization angle are automatically adjusted to obtain a high-quality image suitable for follow-up processing; and the first determination module is used for performing multi-scale wavelet transform decomposition according to the acquired high-quality image, identifying a surface defect area by analyzing texture features and edge information in different frequency components, and judging that the surface defect area is a potential defect area if a wavelet coefficient in the high-frequency component exceeds a preset threshold value. The detection performance is obviously improved.

The invention provides a polaroid defect detection method and system based on deep learning, and the method comprises the steps: obtaining an initial image data set corresponding to a to-be-detected polaroid; extracting defect candidate region features in the polaroid surface image and texture distribution features of the polaroid surface from the initial image data set through image preprocessing and feature extraction operation; inputting the defect candidate region features and the texture distribution features into a pre-trained defect identification deep learning model to carry out joint defect identification operation, and generating a defect preliminary identification result of the polarizer surface image; and determining the defect type of the defect existing in the polaroid to be detected and the spatial distribution characteristic information of the defect on the surface of the polaroid based on the preliminary defect identification result. According to the invention, effective connection between the defect detection result and the production quality control process can be realized, and the practicability of polaroid defect detection and the guiding value for the production process are improved.

The invention relates to the technical field of optical lens defect detection, and particularly discloses an optical lens laser-induced damage on-line detection method and system, a linear polarizer and a narrow-band filter are connected in series in a detection laser light path, non-target polarized light is filtered through polarization direction matching, meanwhile, interference of the environment and scattered light is inhibited through the narrow-band filter, and the laser-induced damage on-line detection system is obtained. According to the method, external source noise such as ambient light and non-target polarized light is reduced through polarization matching and narrow-band filtering, randomness of speckle noise is offset through multi-angle collection and signal fusion in a visual detection mode, exposure is dynamically adjusted, an image is fused to improve the signal-to-noise ratio, noise and real signals are decoupled through self-supervised learning, and the real-time performance of the system is improved. Dust interference is removed in combination with morphological operation; a deep learning reasoning model enhances the damage identification capability in a noise environment, defocusing blur caused by mechanical vibration is eliminated through phase conjugate correction, and the influence of photoelectric conversion noise, dust interference and the like on the detection efficiency and accuracy is remarkably reduced through multi-link linkage.

The invention relates to the technical field of image data processing, and discloses a fine metal powder defect detection method and system based on image recognition, and the method comprises the steps: illuminating a metal powder region through a non-polarized light source, and collecting two images in an orthogonal polarization state through imaging equipment with a linear polarizer, according to the method, the defect morphological fingerprints are constructed through the polarization information entropy, the three-dimensional structure information is converted into light field order degree change for detection, the dimension limitation of traditional two-dimensional imaging is broken through, and the detection accuracy is improved. Hidden defects such as internal pores and aggregates can be accurately identified, and meanwhile, stable detection and material defect cross discrimination under a dynamic working condition are realized in combination with motion compensation and multiband entropy ratio verification.

The invention relates to an antistatic PET (Polyethylene Terephthalate) base film for preparing a polaroid release film and a preparation method thereof, the release film base film is prepared by taking an optical-grade PET slice as a main body, adding modified PET with a specific structure and a modified SiO2 filler, and carrying out co-extrusion casting, a unique three-section stretching process and coating with a coating liquid. According to the invention, material modification and process improvement are carried out, specifically, an optical-grade PET slice is taken as a main body material, modified PET and a modified SiO2 filler with a specific structure are added, a film is prepared through co-extrusion casting and a unique three-section stretching process, and then the surface of the film is coated with a layer of antistatic coating liquid, so that the antistatic film is obtained. The finally prepared base film has low alignment angle, low transverse hot shrinkage rate and high surface adhesion, keeps the characteristics of high light transmittance and low haze of an optical-grade polyester film, endows the film with certain antistatic property, and is particularly suitable for being used as a release film of a high-end polaroid.

The invention discloses a naked-eye 3D display optimization method based on real-time eyeball tracking, and particularly relates to the technical field of naked-eye 3D display, and the method comprises the steps: capturing eyeball movement data in real time through a visual angle tracking sensor, and collecting illumination information in combination with an ambient light sensor; depth perception parameters are calculated based on pupil diameter variation and frequency, and a time sequence prediction type dynamic compensation coefficient is generated in combination with eyeball movement acceleration; acquiring an initial fixation point coordinate by using an improved spherical projection mapping model, and performing compensation coefficient correction to obtain a real-time coordinate; and finally, according to the real-time coordinates, dynamically adjusting the refractive index distribution of the nanostructure layer, the rotation angle of the polarizer, the focal length of the optical lens and other optical modulation parameters. The real-time distance is calculated through the binocular parallax algorithm, the depth mapping value is generated by combining the focal length of the camera and the baseline distance, the method can adapt to the illumination change and the user view angle, and the 3D display effect is optimized.

The embodiment of the invention discloses an optical film, a polaroid and a display device. The optical film comprises a first base layer; the second base layer is positioned on at least one side of the first base layer; the first base layer has a first solid phase; the second base layer contains at least two second solid phases; in the at least two second solid phases, two adjacent second solid phases are connected to form a plurality of interfaces, the plurality of interfaces are distributed in the second base layer, and the two second solid phases forming the interfaces are made of different materials. The multiple interfaces are distributed on the second base layer, so that directional reflection of light on the second base layer is reduced, and the anti-dazzling effect is achieved. Besides, the optical film can also provide good light transmittance and higher mechanical strength, so that the integration of an anti-dazzle function is realized on the protective base material of the polaroid, and the thickness and the manufacturing cost of the polaroid are effectively controlled.

The invention discloses an intelligent water quality monitoring and evaluating system based on image recognition, which relates to the technical field of environment monitoring, and comprises a fusion module for controlling a polarizer array to rotate based on an environment parameter set, capturing water surface optical images in different polarization directions, and performing image reconstruction through a polarization characteristic tensor decomposition method, generating a high-definition water surface image after reflection suppression; the three-dimensional diagram generation module is used for acquiring a morphology stripe image of the water surface through a DLP projection method, and generating a three-dimensional depth diagram in combination with the high-definition water surface image; the pollution identification module is used for correcting the three-dimensional depth map based on the real-time water temperature data, identifying spatial distribution of pollutants through a dynamic structure element opening and closing algorithm and generating a three-dimensional pollution distribution map; according to the method, mirror reflection noise is suppressed through multi-angle polarization image fusion, and the distinguishability of pollutant characteristics is remarkably enhanced while the image resolution is kept.

The invention discloses a transformer oil leakage detection method and device based on polarization-ultraviolet fusion imaging, and the device comprises a housing, a support, a camera, an environment induction device, an overall controller, a power supply, a polaroid rotating wheel assembly, a lens seat assembly, and an image processor. And the motor driver, the illumination intensity sensor, the ultraviolet irradiance sensor, the image processor and the power supply are electrically connected with the integral controller respectively. According to the invention, a multi-angle polarization image and a non-polarization image in the same field of view can be acquired, and then polarization characteristics contained in an oil stain fluorescence signal are extracted and effectively distinguished from non-polarization characteristics of background light; in the daytime mode, the transformer oil leakage detection device can identify a target area with relatively high polarization intensity, and through image fusion enhancement processing, non-target background signals are significantly suppressed, and the fluorescence significance of an oil leakage characteristic area is improved.

The invention discloses an all-optical logic operation system and operation method based on a metasurface device, and mainly solves the technical problems that an existing optical logic gate is high in system complexity, not visual enough in judgment result, high in recognition difficulty, poor in practicability and the like. The logic operation system comprises a polaroid, an object plane, a metasurface device and a detector which are arranged in sequence. The polarizer is used for adjusting the polarization direction of incident light; a plurality of transparent target areas with different shapes are arranged on the object plane and are used for placing corresponding target images; the centers of all the target areas are uniformly distributed on a circle with the center of the object plane as the circle center and d as the radius; incident light reaches the metasurface device after passing through the polaroid and a target image on the object plane, optical logic operation is carried out through the metasurface device, and then the incident light is output to the detector for imaging. The invention has the advantages of simple structure, quick function switching, miniaturization, high integration and the like.

The invention discloses a polarization spectrum modulation type multispectral stereo imaging method which solves the problem that in the prior art, an existing polarization spectrum imaging scheme does not achieve three-dimensional reconstruction of a target and achieves the purpose that the three-dimensional reconstruction of the target is not achieved under the condition that active illumination or special marks are not needed. Synchronous high-precision reconstruction of physical attributes and three-dimensional geometry of the surface of the target is realized; the method comprises the following steps: uniformly modulating polarization information and spectral information of incident light of a target through a three-way optical filter and a polaroid to obtain modulated incident light information; performing aliasing acquisition of a plurality of polarization spectrum components on the modulated incident light information through a multi-color detector combination to obtain aliasing light intensity; performing linear solution on the aliasing light intensity to obtain each polarization spectrum component vector, calculating the polarization degree and the polarization angle of each channel, and further deriving a surface zenith angle and an azimuth angle; reconstructing the three-dimensional morphology of each spectrum channel through normal gradient field frequency domain integration; and finally, fusing the multi-spectral three-dimensional data to obtain a multi-spectral three-dimensional imaging result.

The invention relates to the technical field of image recognition, in particular to a plate defect recognition and detection method based on an image recognition model. The method comprises the following steps: aiming at the technical problems of insufficient texture direction identification precision and difficulty in defect type distinguishing in a traditional plate surface detection method, the invention provides an intelligent detection solution based on polarization imaging. A multi-angle polarization measurement system is constructed through a fixed polarizer and a rotatable analyzer, and omnibearing polarization characteristic collection of the surface of a steel plate is achieved. A polarization intensity change model is established based on the Malus law, the polarization degree and polarization angle parameters of each pixel point are extracted, and a polarization parameter spatial distribution diagram reflecting the surface microstructure is constructed; through statistical analysis of polarization angle distribution characteristics, a rolling direction dominant angle is identified by adopting a peak detection algorithm, and accurate classification and severity evaluation of defects are realized in combination with anisotropy characteristic analysis.

The invention relates to a secondary harmonic characterization system based on spatial light regulation and control. The secondary harmonic characterization system comprises an incident light path unit, a detection light path unit and a sample table, the incident light path unit sequentially comprises a laser, a polarizer, a half-wave plate, a light modulator, a long-pass optical filter and an incident objective lens in the light beam incident direction; a wafer is carried on the sample table; the detection light path unit sequentially comprises an adjustable detection objective lens, a light path adjuster, a polarization analyzer, a short-pass optical filter and a detector in the light beam reflection direction; according to the SHG signal representation detected by the detector, all control parameters of the light modulator, the adjustable detection objective lens, the light path adjuster and the sample table are regulated and controlled, and the SHG signal receiving efficiency of the detector is improved. According to the invention, it is ensured that the detector efficiently receives the SHG signal, and the SHG characterization precision is improved.

The invention discloses a method for detecting residual stress of a birefringent crystal, which is characterized by comprising the following steps of: fixing a sample to be detected on a sample loading table; the imaging lens is used for acquiring light rays which sequentially penetrate through the polarizer module, a sample to be detected on the sample loading table, the analyzer module and the camera module in four states in three states that polarization axes of the polarizer module and the analyzer module are mutually orthogonal and a polarization angle is gradually increased by 30 degrees, and in a state that the polarizer module and the analyzer module are in parallel, and the imaging lens is used for acquiring the light rays which sequentially penetrate through the polarizer module, the sample to be detected on the sample loading table, the analyzer module and the camera module in the four states; collecting a light intensity matrix set through a camera module; acquiring a reference light intensity matrix through normalized linear superposition, and performing pixel-by-pixel operation with the reference light intensity matrix on the basis of the first light intensity matrix, the second light intensity matrix and the third light intensity matrix to acquire corresponding phase delay matrixes; eliminating natural birefringence and updating a phase delay matrix by deducting respective overall average phase delay amount pixel by pixel; through pixel-by-pixel weighted stacking, isogradient lines are eliminated, and distribution information of residual stress is obtained.

The invention discloses a liquid crystal display filtering and light transmission performance monitoring system and a monitoring method thereof, and relates to the technical field of liquid crystal displays. An ambient light real-time monitoring module; a dual-optical-path differential measurement module; a signal processing and intelligent compensation module; a polarizer dynamic adjustment module; a data storage and analysis module; light intensity fluctuation data are collected in real time through an ambient light real-time monitoring module, reference light and transmission light are synchronously collected through a double-light-path differential measurement module, a signal processing and intelligent compensation module calls a self-adaptive algorithm library, compensation coefficients are calculated in combination with ambient light spectrum data, and a polaroid adjusting instruction is generated. And then an adjusting instruction is sent to the polaroid dynamic adjusting module through the CAN bus, the polaroid dynamic adjusting module feeds back an actual thickness value in real time after adjustment is completed, closed-loop control is formed, and through real-time compensation of ambient light and dual-light-path differential measurement, the influence of a station LED lamp and natural light is eliminated, and the monitoring precision of light filtering and light transmission performance is improved.

The invention discloses a cylindrical Luneberg lens antenna with azimuth plane and pitching plane scanning capability, which comprises a Luneberg lens, the Luneberg lens comprises a support plate and a plurality of dielectric plate units arranged on the support plate, the thickness of each dielectric plate unit is gradually changed, and the dielectric plate units are anisotropic; a first feed waveguide disposed on a side surface of the luneberg lens to perform linear polarization beam scanning; and the second feed waveguide is arranged at the bottom of the luneberg lens so as to carry out circular polarization beam scanning. According to the antenna, the scanning dimension of the cylindrical luneberg lens is expanded, beam scanning of an azimuth plane and a pitching plane is realized, and meanwhile, the advantages of simple feed and low cost of the antenna are reserved; and by using the anisotropic unit, the functions of the cylindrical luneberg lens and the polarizer are integrated into a single structure, so that the structural compactness is improved on the premise of not sacrificing the original beam scanning performance of the azimuth plane and the pitching plane. The invention relates to the technical field of antenna engineering.

The invention relates to an aspheric wavefront detection device and method based on multi-direction orthogonal lateral shear interference. The device is composed of a laser, a linear polarizer, a light splitting element, a reflector array, a two-dimensional orthogonal grating array, a light splitting system, a polarization phase shifting element and a CMOS camera. The method comprises the following steps: firstly, an antisymmetric continuation method is included, secondly, dynamic phase recovery and distortion compensation are adopted, Zernike polynomial local fitting is introduced, and self-adaptive compensation is carried out on high-order aberration (such as coma aberration and trefoil aberration) of an aspheric surface edge region. According to the method, the multi-direction orthogonal lateral shearing interferogram can be obtained through single measurement, and a high-precision, high-efficiency and high-robustness solution is provided for precise detection of the aspheric optical element through cooperation of an algorithm and hardware. The method is suitable for high-precision phase recovery in the fields of optical detection, microscopic imaging and the like, and is suitable for high-precision dynamic detection of complex optical elements such as off-axis aspheric surfaces, free-form surfaces and the like.

The invention discloses an intelligent sensing system for monitoring the quality of a cold end of a float glass production line, and relates to the technical field of glass production. The device comprises a top displacement beam and a bottom displacement beam which are respectively provided with an image sensor and a reflective mirror assembly, and synchronous detection of glass thickness and internal stress is realized in cooperation with a monitoring medium generation unit capable of adjusting the beam diameter. The thickness is calculated by using the refraction offset after the light beam passes through the glass, stress fringes are generated through the double-polaroid structure, and stress monitoring is realized in combination with an image sensor. The screw rod and the transmission belt driving device realize synchronous closed-loop control under the feedback of the grating ruler, so that the light path and the sensor reciprocate in the width direction of the glass, and real-time scanning of the whole glass is completed. The diameter of the light beam can be adjusted to consider accurate thickness measurement and stress fringe imaging, and the system has the advantages of high precision, full coverage, real-time performance and high automation degree, and is suitable for intelligent detection of the quality of the cold end of the float glass.

An optical stack including an optical diffuser and a first reflective polarizer disposed on the optical diffuser is described. For substantially normally incident light and for nonoverlapping first and second wavelength ranges: the optical diffuser has a first scattering rate R1 for at least one wavelength in the first wavelength range, and a second scattering rate R2 for at least one wavelength in the second wavelength range, such that R1 / R2 is greater than or equal to 2. The first reflective polarizer may transmit at least 40% of light for a first polarization state for each wavelength in the first wavelength range, may reflect at least 70% of light for an orthogonal 10 second polarization state for each wavelength in the first wavelength range, and transmit at least 40% of light for each of the first and second polarization states and for each wavelength in the second wavelength range.

A camera with a direction-adjustable polaroid relates to the technical field of camera equipment and comprises a shell, a lens body and a lens mounting rack, the lens body and the lens mounting rack are arranged in the shell, the shell comprises a camera cabin and a protective front cover, and a lens channel is arranged in the middle of the protective front cover; a plurality of spiral guide grooves are distributed in the outer wall of the lens body at equal intervals; a driving motor is arranged at the top of the lens mounting frame, a driving gear is arranged at the output end of the driving motor, a gear ring meshed with the driving gear is arranged on the front side of the lens mounting frame, and a guide block corresponding to the spiral guide groove is arranged on the inner side of the gear ring. According to the structural design of the utility model, the lens can automatically telescope and rotate, and the internal polaroid rotates synchronously, thereby realizing shooting of light at different angles, and improving the picture effect shot by the camera.

The invention relates to the technical field of optical imaging, in particular to imaging equipment and an imaging method based on multi-dimensional optical perception, the equipment comprises a lens, a rotary dimming mechanism, a fast reflecting mirror, a broadband visible light high-speed camera and a controller, and a turntable of the rotary dimming mechanism is provided with an optical filter and polaroids with different polarization angles; a target light source enters from the lens, passes through the rotary dimming mechanism and is reflected to the broadband visible light high-speed camera by the fast reflecting mirror; the controller is in communication connection with the rotary dimming mechanism, the fast reflecting mirror and the broadband visible light high-speed camera, the controller cooperatively controls the rotary dimming mechanism, the fast reflecting mirror and the broadband visible light high-speed camera, the inherent space registration error of a multi-aperture system is fundamentally eliminated, and meanwhile, the equipment is compact in overall structure, low in cost and high in practicability. Miniaturization, light weight and low power consumption are realized, and microsecond-level cooperative control of the fast reflecting mirror, the rotary dimming mechanism and the broadband visible light high-speed camera is realized through dual-path FPGA cooperative processing.

The disclosure provides a display module and a display device. The display module includes a display area and a non-display area. The display module further includes a substrate, and a first signal line, an inorganic protective layer, a spacer layer and a polarizer which are disposed on the substrate. The inorganic protective layer is located at least in the non-display area and on a side of the first signal line away from the substrate, the spacer layer is located at least in the non-display area and between the inorganic protective layer and the substrate, and the polarizer is located on a side of the inorganic protective layer facing away from the substrate and covers the display area and extends to the non-display area. In the non-display area, the polarizer includes a first boundary.

The invention relates to a linear structured light sensor polarization correction method and system based on reflected polarized light, and the method comprises the steps: obtaining the reflected light intensity of the surface of an object at different polarization angles, calculating a Stokes vector according to the reflected light intensity, building a mapping relation between the reflected light intensity and an incident angle based on the Fresnel law, and correcting the polarization of the linear structured light sensor. Obtaining a light intensity maximum value and a light intensity minimum value; calculating a linear polarization degree based on the maximum light intensity value and the minimum light intensity value, and obtaining an optimal laser incident angle based on the linear polarization degree and the refractive index of the object; constructing a polarization optimization model of a polarization angle and an incident angle by using a Stokes vector, and solving an optimal polarization angle; and acquiring a light stripe image of the polaroid at the optimal polarization angle, and performing polarization correction on the light stripe image based on a Stokes vector to realize three-dimensional measurement of an object. According to the invention, errors caused by factors such as light intensity, incident angle and image quality are effectively reduced, and the measurement precision is greatly improved.

The invention provides a low-noise speckle interference system and method based on a spatial light modulator, and relates to the technical field of speckle interference, and the system comprises a laser, a first beam splitter prism and an imaging element. A laser beam emitted by the laser is divided into transmission light and reflected light by the beam splitter prism I; after being reflected by the third beam splitter prism, part of the transmission light is irradiated on an imaging element as reference light; part of the reflected light sequentially passes through a linear polaroid and a half-wave plate, is modulated by a spatial light modulator assembly, irradiates a fourth beam splitter prism, and is reflected to the surface of a measured object to generate diffuse reflection, so that slow-reflection light is obtained; according to the speckle interference system, object light is modulated by using a spatial light modulator assembly, so that emergent light modulated by the spatial light modulator assembly irradiates a measured object at various illumination angles, mutually independent speckle fields are formed on a target surface of an imaging element, speckle decorrelation noise can be effectively inhibited after multiple times of measurement and superposition, and the measurement accuracy is improved. And the accuracy of subsequent measurement results is improved.

The utility model relates to a broadband wide-beam horn antenna, which comprises an antenna main body, a feed port, a feed probe, a polarizer, a waveguide and a beam widening structure, the antenna body is in a cuboid shape with an opening in the upper middle end inside, through holes are formed in the left side face and the right side face of the antenna body, feed ports are connected to the through holes, feed probes are arranged in the feed ports, a polarizer is vertically connected to the bottom face inside the antenna body, and the polarizer is located between the two feed probes. The open end of the antenna main body is connected with a waveguide, and the inner diameter of the waveguide is gradually increased along the direction close to the antenna main body to form a horn shape with a big-end-down opening; the side surface of the waveguide is provided with a wave beam widening structure which extends outwards. The antenna with the structure has the advantages that the antenna with the structure can achieve the wide-beam antenna gain of 1.5 dB within + / -60 degrees and the wide-beam antenna gain of-0.5 dB within + / -70 degrees; and the working bandwidth can reach 10%. And the diameter is only 1.27 times of the wavelength of the lowest working frequency.

The invention discloses a semiconductor laser, which comprises a laser light source; the polarizer comprises an incident side, a first reflection light-emitting side, a second reflection light-emitting side and a transmission light-emitting side; the first wave plate is arranged on the first reflection light emitting side; the second wave plate is arranged on the transmission light-emitting side; during working, laser emitted by the laser light source comprises first polarized light and second polarized light, the polarization directions of the first polarized light and the second polarized light are perpendicular to each other, and the laser enters the polarizer from the incidence side; the first polarized light is reflected by the polarizer, passes through the first wave plate to be subjected to polarization turning and is emitted along a first emergent light path, and part of light reflected back along the first emergent light path on the working surface passes through the first wave plate to be subjected to polarization turning again and passes through the polarizer to be emitted from a second reflection emergent light side; the second polarized light passes through the polarizer and the second wave plate to be subjected to polarization turning and is emitted out along a second emergent light path, and part of light reflected back along the second emergent light path on the working surface is subjected to polarization turning through the second wave plate again, then enters the polarizer and is reflected out from the second reflection emergent light side.

A zero-optical-path-difference double-frequency heterodyne grating ruler comprises a light source, a signal detecting and processing system, a polarization splitting prism, a first quarter-wave plate, a rectangular prism, a second quarter-wave plate, a third quarter-wave plate, a total reflection mirror, a long-strip prism, a reference grating and a 45-degree-placed polaroid. The two measuring light paths of the system always keep zero optical path difference, so that the measuring precision can be ensured, and the environmental stability of the system is also remarkably improved. And a high-precision and high-robustness measurement scheme is provided for precision equipment such as a photoetching machine and a precision motion platform.

The invention provides a polaroid, an optical functional layer coating and a display device. The polaroid comprises an optical function layer, and the optical function layer comprises thermocuring resin, first ultraviolet curing resin, second ultraviolet curing resin and needle-shaped particles. The molecular weight of the thermocuring resin is 500,000-1,500,000, the number of acrylic functional groups of the first ultraviolet curing resin is 5-50, the number of acrylic functional groups of the second ultraviolet curing resin is 2-5, and the ratio of the length of the needle-shaped particles to the diameter of the cross section is 5-60. The optical functional layer coating comprises the components, a photoinitiator, a dispersing agent and a solvent, and the mass of the needle-shaped particles accounts for 6-18% of the mass of the optical functional layer coating. The display device comprises a display panel and a polaroid. Through specific combination of the three kinds of resin and the needle-shaped particles, the technical problem that the viewing angle increasing capacity of the polaroid is limited is solved.

A visible light communication apparatus comprising: multiple sources, at least one source being a light source configured to transmit a data signal; and a receiver comprising a polarizer, operating in a visible light spectrum, the receiver configured to receive visible light energy from the one or more sources; the polarizer configured to filter multiple noise signals and allow the data signal to pass through to the receiver. Allows more signal light than background light to reach the sensor, the polarizer improves signal to noise ratio for outdoor visible light communication.