By introducing photosensitive chiral molecules into the heliconical cholesteric liquid crystal, a photoresponsive heliconical cholesteric liquid crystal system is designed. Under the synergistic effect of electric field and optical field, the selective reflection of the heliconical structure can be adjusted from visible light to near-infrared region. The tuning range of the reflection spectrum of the heliconical structure is related to the initial helical twisting power of the system. The heliconical cholesteric liquid crystal realizes a broad spectral range (about 580 nm) from visible light to near-infrared region under the modulation of electric field through adjusting the concentration of the chiral photosensitive molecule. Meanwhile, by modulating the power of the non-polarized ultraviolet light field, the tuning range (about 530 nm) of the heliconical cholesteric liquid crystal covering the entire visible light region and the near-infrared region is obtained under a fixed electric field. Such broad spectrum modulated by optical field mainly depends on the thermal effect of optical field and photoisomerization effect of azobenzene. In addition, due to the electric field dependence of the heliconical structure, the optical field modulation interval of the heliconical cholesteric liquid crystal reflection band can be controlled by electric field.

A cross-linkable zwitterionic amphiphile was designed and synthesized, which can self-assemble into lyotropic liquid crystals for the fabrication of ordered polymeric nanostructure. Bifunctional polymerizable methacrylate groups were introduced into the amphiphilic molecule to afford structural crosslinking by radical polymerization, which can be realized by the use of 1,10-dibromodecane and diethyl malonate as starting materials in the synthesis. Then the quaternization with 1,3-propanesultone yielded the final zwitterionic product that was confirmed by nuclear magnetic resonance spectroscopy (NMR). Lyotropic liquid crystals of the molecule in water were prepared and characterized by polarizing optical microscopy (POM). Hydration of the amphiphile can form only lamellar mesophases. According to the critical packing parameter (CPP) theory, the molecular CPP of this amphiphile is between 1/2 and 1 that preferred the formation of lamellar mesophases.

Cholesteric liquid crystals with broadband reflection properties have a wide range of applications in many fields. In order to expand the method of modulating the reflection band and achieve band modulation in the desired spectral range, a new polymer-stabilized cholesteric liquid crystal device with polymer network gradient distribution is prepared by adding UV-absorbing dyes. The experimental results show that the gradient distribution of polymer network makes a significant difference in the elasticity of polymer network near the upper and lower surfaces of the cell, so that its electrically induced reflection band broadening can be tuned by changing the direction of the direct current electric field. When the cell thickness is 40μm and the dye concentration is 1.2% of PSCLC, the reflective band facing the light source as the positive pole is located at 570~778 nm when a 12 V DC electric field is applied, and the reflective band is red-shifted to 598~816 nm after changing the electric field direction. This research provides a new strategy for broadband reflective cholesteric liquid crystal materials that have potential applications in smart windows, laser protection, data storage, etc.

In order to study director arrangement of the cholesteric liquid crystals layer with planar texture (CLCPT) in parallel anchored (PA) and orthogonal anchored (OA) cells with temperature changes, two samples of CLCPT in PA and OA cells were prepared respectively. A fully leaky guide mode structure consisting of two trapezoidal low refractive index prisms, the refractive index matching liquids and one CLCPT cell was constructed. The method of fully leaky optical guided wave (FLOGW) was introduced to measure the experimental curve of reflectivity Rss with inner angle (the incident angles of the test light incident on the CLCPT layer) at different temperatures. The temperature dependence of the theoretical curves revealed by simulations based on elastic theory of liquid crystal and multi-layer theory was in agreement with the experiment result, and the characteristics of CLCPT director arrangement with temperature changes in PA and OA cells were accurately analyzed. In addition, the actual birefractive index values of cholesteric liquid crystal (CLC) at different temperatures were measured by the control variable method.

Under the background of the bottleneck of Von Neumann architecture, artificial synaptic devices inspired by biological nerve have gained extensive attention to accelerate peoples steps towards the era of artificial intelligence. In this study, the effect of hydroxyl group on the synaptic performance of p-type organic thin film transistor (OTFT) is investigated by plasma treatment on the surface of SiO2 dielectric layer. The synaptic behaviors of OTFTs with different plasma treatment time are simulated and compared, including Excitatory Post-Synaptic Current(EPSC), Paired Pulse Facilitation(PPF)and Long-term Potentiation(LTP). The generation of synaptic properties is due to the electrons being trapped by the hydroxyl groups introduced into the semiconductor layer/ dielectric layer interface by plasma treatment. With the increase of plasma treatment time, more hydroxyl groups on the surface of the dielectric layer make OTFTs exhibit better memory and retention capabilities, and higher linearity, which is more conducive to its application in brain-like learning and neural computing.

Micro-LED is emerging as new generation display technology due to their advantages of high efficiency, wide color gamut and long life. Although there are already many Micro LED based products and demons, the commercialization of Micro-LED technology still suffers from many technical challenges. In this short review paper, we describe the definition of Mirco-LED with a short summary of the milestones. From the perspective of the developments, we find that the integration process plays an important role in the fabricating Micro-LEDs. We then discuss the key fabrication processes of Micro LEDs with a focus on the technical challenges. In the end, a short perspective is also presented to discuss the future directions. Micro-LED display is still suffering from a number of technical challenges including mass transfer, full color technology, while the features of high resolution, fast response, low power consumption and long lifetime make them the most promising candidates for ultra-small and ultra-large displays demands, such as virtual/augmented reality and electronic billboards. These potebtial applications have motivated the exploration and investigation from both of academia and industry.

The liquid crystal bubble defect occurred in large-size products under high-temperature-operation-test are systematically analyzed and summarized from the occurrence of the defect, hypotheses on the mechanism, and through experimental tests to verify the hypothesis mechanism. It is concluded that the adhesive of the sealant is reduced greatly in the high temperature environment, resulting in the formation of liquid crystal bubble defect. At the same time, it is demonstrated that by selecting sealant materials with high Tg point and optimizing the bonding interface, the high-temperature adhesion is improved, thereby the problem is solved effectively, the product quality is ensured, and the production yield of LCD monitors and customer satisfaction are improved.

The OLED screen COF (Chip on Film) connection transition zone is prone to the problem of metal layer fracture in the bending and reliability stages. In this paper, the COF bending traveled of flexible screen is showed. And the finite element method is used to analyze the influence of those factor, such as the offset of related structure in the transition zone of COF connection, the thickness of the adhesive layer on the stress of the metal layer under the bending process and the reliability factors. Meanwhile,the change of metal layer stress is researched after bending path altered. The results show that the maximum stress amplitude of metal layer in bending process increases obviously with U-film shifting to the left and right, bending path moving up and down, and also increases gradually with Foam shifting from left to right and the thickness of the metal cover layer (MCL) glue increasing. In the reliability results, the maximum stress on the metal layer is decreased then stable with the deviation of U-film and Foam from left to right, and is increased and then decreased with the increase of the MCL thickness added. The analysis results provide a reference for the design of the stacking structure and the control of its attached deviation interval in the bending zone. Meantime, it provide a theoretical basis for the design of the bending path and troubleshooting analysis.

In order to solve the problem of high temperature vertical crosstalk in large size thin film transistor liquid crystal display (TFT-LCD) quickly, the quantitative relationship between leakage current and V-CT phenomenon was studied to provide guidance of the process adjustment of TFT characteristics. Firstly, based on the contour map of Vgl~~TCON characterized the occurrence of V-CT and the leakage current of TFT in actual working state, a method was developed to characterize the relationship between leakage current and severity of V-CT quantitatively. Secondly, according to the study of V-CT in CT-SEC image, the following conclusions are obtained: (1) the contour map and the trend of Ioff~~total match well in different Vgl~~TCON value; (2) V-CT is strongly correlated with the leakage current under the photo Ioff(Vgl~~GOUT-Vpixel~~255-) over any period in high temperature.

Mura is a common defect of thin-film transistor liquid crystal display, which seriously affect the quality of the product. Generally, the performances and root causes of Mura are different and require specific analysis. This paper focuses on a fixed position green stripe Mura on a 81.28 cm(32 in) inch product in 8.5 generation line, and studies the defect mechanism through physical analysis, equipment investigation and testing of different producing conditions. The experimental results show that the change of the properties of the G-1 type photoresist used in the green pixel of color filter is the direct cause of the defect. Furthermore, the root cause is confirmed that the zinc phthalocyanine compounds in the G-1 type photoresist have a strong absorption peaks at 600~700 nm of light wave, so it will absorb photons and transform it to free carriers after illumination. The free carriers form additional electric fields, leading to abnormal liquid crystal deflection in this area, showing the macroscopic green Mura. From the two directions of blocking light and reducing the number of photo-generated carriers, two kinds of improved materials are formed by adding high sensitivity light starter and using pigment molecules with higher color concentration. Both material successfully reduce the incidence ratio of the green Mura defect from about 20% to 0, effectively improving the quality of products.

In order to assist R & D investment and science and technology projects management, the evolution trend of some main display techniques was evaluated. Based on the S-curve evolution trend, new display technology systems development stage and direction were judged. The relationship between R & D investment and market life was analyzed by using the patent quantity in different years. It is showed that liquid crystal and organic light-emitting diode display systems are in the mature and growing period, respectively, E-paper and laser display are in the transitional period, quantum dots and micro light-emitting diodes are in the infancy. A large number of patents indicates a large R & D investment and long market life of a technology. The lower the maturity of the technology system, the higher the invention level of R & D achievements. Therefore, the investment in basic research should focus on infancy, and the investment in R & D of common key technologies should focus on the transition period and the early growth period. The content and leading investors of R & D were put forward.

Color transfer has always attracted much attention in the field of image processing, but the traditional color transfer methods often have problems such as insufficient detail retention, lack of layering, and poor visual effects. To solve the above problems, this paper proposes a new method of local color transfer combining image signature and optimal transmission. Firstly, a salient region detection method based on image signature is introduced to obtain the foreground region and background region of the reference image and the content image, and then color transfer is performed in the corresponding region to improve the layering of the result image. Secondly, on the basis of the traditional linear color transfer model, combined with the optimal transmission theory, a color transfer strategy that maintains the brightness of the content image is proposed to improve the quality of the resulting image well. Finally, in order to evaluate the effect of color transfer more accurately, a new objective evaluation index of color transfer is designed in combination with chromaticity difference and structural similarity. The experimental results show that compared with the traditional color transfer method, the result image obtained by the method proposed in this paper preferably maintains the detailed information and layering of the content image, and has a more admirable visual effect (the comprehensive effect of the new method is about 30% higher than that of the traditional method). In addition, compared with the traditional color transfer evaluation index, the objective evaluation index mentioned in the article is more faithful to the users subjective evaluation result. Experimental analysis shows that compared with the traditional color transfer method, the result image obtained by the method in this paper has more outstanding performance in detail preservation, layering preservation and visual effects, and the objective evaluation index mentioned in the paper is closer to the result of subjective evaluation.

Aiming at the problem of color over-saturation and color cast in the process of defogging, an image defogging algorithm based on YUV color model and guided filtering is proposed. Firstly, the brightness component of the fog image is separated, and the atmospheric veil is refined by combining Laplace sharpening operator and guided filtering to obtain the accurate transmittance, and then the sky area is corrected. Secondly, the dense fog area is located according to the intensity information of the atmospheric veil, and the average value in this area is used as the estimation of airlight. Finally, the chromaticity component is compensated to restore the color saturation of the real scene. The experimental results show that the edge intensity and color fidelity of the image after defogging are greatly improved, and the objective evaluation parameters of information entropy, average gradient and standard deviation are better than the current mainstream algorithms. The proposed algorithm demonstrates that the effect of defogging is remarkable, which can meet the requirements of image visibility and detail clarity.

In order to solve the common problems of current medical images, such as relatively scattered size distribution of pathological areas, the ambiguous detail features, and the big visual difference of similar tissue images, this paper proposes a medical retrieval method integrating multi-scale features and attention mechanism based on the CBMIR system. This method adaptively balances the relationship between shallow image texture features and deep image semantic features by fusing multi-scale features and setting learnable weight coefficients, thereby the networks ability to extract pathological features at different scales is improved. At the same time,this method introduces the attention module and perform channel weighted summation on the feature maps output by the network to improve the feature expression ability of key feature channels, so that the network can pay more attention to the recognizable pathological feature areas in the image accurately. Finally, the multiple losses are used to further optimize the distribution of sample features in the feature space when the loss function is designed. As a result, the retrieval accuracy of 0.95 and 0.98 is achieved on the mAP@100 and mAP@20 indicators on the Mura dataset, which basically meets the retrieval accuracy requirements of the actual scene on the model.

Smoke is an important feature of early fire detection. The extraction of smoke features by traditional machine learning and two-dimensional convolutional neural network smoke detection algorithms are limited to the spatial domain, and cannot extract temporal information. The existing three-dimensional convolutional neural network detection algorithm has the problems of high calculation cost and low detection time efficiency, which leads to unsatisfactory detection accuracy and false alarm rate. To solve the above problems, a smoke video detection method based on deep learning in spatio-temporal domain is proposed. The block moving target detection method is used to extract the moving targets of the smoke video and filter the non-smoke targets. At the same time, the three-dimensional convolutional neural network is split to form a two-plus-one-dimensional spatio-temporal network module, which extracts the characteristics of the spatio-temporal domain and improves the detection time efficiency. In order to suppress irrelevant features, an attention mechanism is introduced to increase the compression and incentive network to recalibrate the weight of feature channels to improve the accuracy of smoke detection. The research results show that the average accuracy rate of the algorithm used in this paper is 97.12%, the average correct rate is 97.06%, the average false alarm rate is 2.74%, and the average detection frame rate is 10.49 frame/s. The needs of fire smoke detection is met, and the detection timeliness is improved significantly.

In order to solve the problems of uneven illumination and low accuracy in the automatic recognition system of pointer instruments, an Otsu algorithm and an improved Hough algorithm are proposed to process the instrument image. Firstly, the instrument image is preprocessed to enhance the characteristics of the instrument pointer area, Otsu algorithm performs the image binarization to segment pixels that only belong to the pointer, and the improved Hough transform is performed to detect the pointer. By quickly extracting the center pixel point of the dial pointer's connected area, combined with the dial center constraint, the double threshold Hough is performed on the extracted pixel point transform straight line detection. Experimental results show that the proposed algorithm detects the meter reading error at about 4.76%, which meets the system accuracy requirements.