最新刊期
期 4 ， 2020
- 摘要：Based on Landau-de Gennes theory, the size effect of spherical droplets with nematic concentric structure and the dynamic process under electric field are investigated. Results show that the concentric structure is stable in the range of radius r ≥ 6.5 μm. When r ≤ 5.1 μm, there is only bipolar structure. When 5.2 μm ≤ r < 6.5 μm, it is degenerate state between bipolar structure and concentric structure. When an electric field is present, at 0 ≤ E/E0 ≤ 0.002 4 (reducing the electric field with E0, E0=33.7 V/μm), the liquid crystal molecules are gradually arranged in the direction of the electric field. When 0.002 7 ≤ E/E0 ≤ 0.003, the elastic energy, surface energy and electric field energy compete with each other to induce the first structural transition, which causes a similar bipolar structure in the droplet. When 0.003 3 ≤ E/E0 < 0.013 4, the directors are arranged in the direction perpendicular to the electric field near the equatorial plane, the upper and lower parts of the sphere are symmetrical and the directors are along the direction of the electric field. When the electric field strength reaches the threshold Ec/E0=0.013 4, the second structural transition is found, which occurs for the first time in the concentric structure. Most of the liquid crystal molecules in the droplets realize the rotation from the central axis to the boundary point by point in the direction of the electric field through the dynamic process.关键词：Landau-de Gennes theory;concentric configurations;structural transition;dynamic process
- 358
- |
- 20
- |
- 2
发布时间：2020-07-05 - 摘要：In the electronic paper industry, the TFT substrates of some products use halftone mask process to reduce the number of mask. After halftone masking, the conventional single wet etching and single dry etching method (1W1D) requires both the thickness and uniformity of the halftone photoresist under control. The high requirements result in multiple rework in photo process, which leads to waste of capacity. Furthermore, the poor etching uniformity of 1W1D results in the thin channel thickness around the glass, which reduces the yield. To solve these two problems, we referred to double wet etching and double dry etching method (2W2D) for non-electronic paper. However, the 2W2D process for non-electronic paper produces a large a-Si tail, resulting in a large parasitic capacitance, which results in product yield loss. In addition, the problems of a-Si residue and channel characteristics also hinder the further improvement of the electronic paper yield. Therefore, we reduced the a-Si tail by reducing the time of both wet etching processes and optimizing the ashing conditions; eliminated a-Si residue by establishing the a-Si treatment process; improved the channel characteristics by adjusting the deposition condition of a-Si film and the pretreatment condition of passivation film. The experimental results show that the improved 2W2D method can fully meet the characteristics of electronic paper. Compared with the 1W1D method, the uniformity of channel thickness was increased by 50% and array test yield was improved by 4%~10%. Moreover, the new 2W2D etching process only needs to meet the standard thickness of photoresist, which reduced the ratio of rework in photo process by 60%. In a word, this improved 2W2D process method effectively improves the channel characteristics and etching uniformity of the electronic paper products, improves product yield, reduces productivity waste, and reduces cost, which plays an important role in 4 mask electronic paper products.关键词：electronic paper;halftone mask;2W2D;channel thickness;channel characteristics
- 398
- |
- 64
- |
- 0
发布时间：2020-07-05 - 摘要：A method of naked-eye 3D video acquisition using a single-camera unmanned aerial vehicle is proposed in order to solve the problem which is difficult for an unmanned aerial vehicle to carry a camera array flight shooting. The method uses a single-camera unmanned aerial vehicle to shoot videos at constant speed in a horizontal direction based on the parallel camera array. The videos with horizontal parallax are acquired by the corresponding frames which are extracted from the shot video with a certain frame distance. The stereo video source for a naked-eye 3D display is produced. The horizontal parallax value of the videos can be adjusted by different frame distances which can be calculated by the shooting distances of different scenes according to the method. The feasibility of the proposed method is verified by the comparison of the experimental results on a naked-eye 3D display. This research provides a reference for the videos naked-eye 3D display by shooting the real 3D scene using the normal unmanned aerial vehicle.关键词：3D video;frame distance;unmanned aerial vehicle;naked-eye 3D display;parallel camera array
- 356
- |
- 25
- |
- 2
发布时间：2020-07-05 - 摘要：To improve the production capacity, the polyimide (PI) film coating method of High Advanced Dimension Switch (HADS) products is changed from APR transfer printing (Roller Coater) to inkjet printing(Inkjet Printer). The change of the coating method caused PI droplets can not to fill into the PVX (passivation SiNx) via hole because of its high thickness, and the PI solution accumulated around the PVX via hole caused "line Mura" issue. By changing product design and process parameter adjustments and process optimization, we try to reduce or eliminate defective products ratio, so that yields could meet the demand for mass production. Firstly, we change the PVX mask to make a shift between PVX via hole and Com electrode (half via hole on metal). The design of half via hole helps PI solution to enter PVX via hole. In order to reduce the adverse effect of PVX via size and number on PI solution diffusion, the PVX via hole period is changed from 1/3 to 1/6, and the via hole size is changed from 5.7 μm to 7.5 μm. The design of the PVX mask has greatly improved the entry of PI solution into via hole, which reduces the failure rate from 100% to 15%. Secondly, to improve the uniformity of PI thickness, we change the coating frequency of inkjet printer from 1 time to 2 times, which improves the diffusion time between adjacent droplets, then the droplets spacing is smaller and the film thickness has higher uniformity, its failure rate reduces from 15% to 1%. Thirdly, we improve the diffusion uniformity by changing the diffusion direction of PI solution, and by changing the coating direction of inkjet printer from 0° to 2°, the failure rate is reduced from 1% to 0.2%.关键词：PVX via hole;polyimide solution;inkjet printing;diffusion;process optimization
- 407
- |
- 72
- |
- 0
发布时间：2020-07-05 - 摘要：In the TFT-LCD industry, Fringe Field Switching(FFS)technology in the production process is easy to lead to the high incidence of Zara, reduces the product yield and increases the production cost. According to the phenomenon of lighting, the defects of Zara can be divided into four categories:scattered Zara, clustered Zara, bright spots and unconfirmed bad stains of panel. Through a large number of screen analysis, it is found that Zara is closely related to the internal cleanliness and cleaning capacity of After-Rubbing-Cleaner. This paper studies the improvement of filter diameter reduction, KOH process optimization, direct water supply transformation, chamber pollution reduction and so on. Through mechanism analysis and a large number of tests, Zara is improved from 0.74% to 0.24%. It is verified that the cleaning degree of After-Rubbing-Cleaner is important to improve Zara. At the same time, good economic benefits are obtained:the annual income is 13.38 million yuan.关键词：Zara;after-rubbing-cleaner;direct water supply;cleanliness;microorganism;cleaning capacity
- 375
- |
- 65
- |
- 0
发布时间：2020-07-05 - 摘要：With the development of the thin film transistor-liquid crystal display (TFT-LCD) on size and resolution, the traditional interface transmission protocol between the timing controller (T-CON) and the specific source driver (SD) is no longer applicable and it becomes a critical challenge for the conventional interface protocol. In order to improve the high-speed transmission of data signals, this paper proposes and studies a novel high-speed point-to-point interface transmission protocol in the display panel field, named China Standard Point-to-Point Interface (CSPI). The CSPI protocol implements clock calibration between T-CON and SD through embedded Clock Data Recovery (CDR) mechanism. After CDR calibration completes, the instruction signal Link Status (LS) outputs high level to T-CON, informing the sender that the next stage of valid data can be transmitted. The CSPI technology specific packet alignment data is also embedded in the transmission data line. The particular 8B/9B coding technique is adopted for data transmission as well as a scrambling scheme. Compared with the traditional mini-LVDS interface protocol, CSPI technology can improve transmission rate to 3 Gb/s, and has outstanding features of high data rate and less signal lines which is particularly well-suited for high-end TFT-LCD panel. Moreover, CSPI technology built-in clock signal, which can effectively reduce EMI. Experimental results based on the 55" Ultra-High Definition (UHD) LCD panel indicate that the minimum amplitude and width of the eye diagram are approximately 312 mV and 548 ps, respectively. It can satisfy the system requirements of the stability, reliability and anti-interference ability of the transmitted signal as well as reduce Printed Circuit Board (PCB) layout area.关键词：China standard point-to-point interface;mini-lvds;timing controller;source driver;embedded clock data recovery;8b/9b coding technique
- 449
- |
- 52
- |
- 1
发布时间：2020-07-05 - 摘要：In the TFT-LCD cell PI coating process, the film thickness and uniformity of polyimide alignment film and the quality of coating film surface are the most important. The effects of ink-jet coating on the quality of alignment film are studied. Firstly, the ink-jet coating process is optimized, the influence of the spray frequency on the amount of vomiting is analyzed. The frequency of vomiting has a significant impact on the amount of vomiting and its uniformity. Secondly, the effects of negative pressure, coating speed, solid content of the solution and coating density on the surface quality of the film are analyzed. When the frequency of vomiting is 1 000~8 000 Hz, the uniformity of the amount of vomiting can meets the requirements. When the frequency of vomiting reaches 10 000 Hz, the amount of vomiting is seriously uneven, which can not meet the production demand. The optimum conditions of spraying frequency, vomiting volume, negative pressure, coating speed, solid content of the solution and coating density are obtained as follows:3 000~5 000 Hz, 50~70 pL, center value±100 Pa, 500~600 mm/s, (3.9±0.4)%, 50%~50.3%. Reducing the solid content of the solution of the alignment membrane can improve the non-uniform coating defects, changing the vomiting density can improve the non-uniform coating defects, and improve the quality of the painting. In this paper, the quality optimization of directional film coating in box-making section has achieved good results, which can meet the needs of mass production in engineering practice.关键词：TFT LCD;cell process;alignment film coating process;inkjet coating
- 383
- |
- 48
- |
- 0
发布时间：2020-07-05
Materials and Devices
- 摘要：Images generated by image denoising algorithms often result in missing details due to loss of high frequency information. In order to restore the high-frequency details of the reconstructed images and enhance the representation ability of the network, a noise removing network based on local expectation-maximization attention(LEMA) is proposed. The network uses the classic autoencoder as the basic module to achieve sufficient depth, so as to filter out unnecessary low-frequency information and promote network learning high-frequency information. The proposed channel and spatial attention module adaptively learns informativel features by computing the interdependence of image channels and pixel spatial positions. A series of experiments show that the LEMA can recover more high frequency details. On the benchmark BSD68, the PSNR value is about 0.13 dB higher than the state-of-the-art algorithm N3Net, and has better visual quality.关键词：image denoising;local expection-maximization;attention;autoencoder
- 335
- |
- 13
- |
- 2
发布时间：2020-07-05 - 摘要：Aiming to solve the low illumination images of low brightness, low contrast, and blurred edges, an NSCT (Non-Subsampled Contourlet Transform) domain images enhancement algorithm is proposed based on adaptive Retinex and adaptive fractional differential. Firstly, multi-scale NSCT decomposition of low-illuminance images is needed to obtain low-frequency subbed images and high-frequency subbed coefficients. The image brightness of low-frequency images needs to be improved by multi-scale Retinex, and using non-linear bilateral filtering function to estimate the illumination component. The illuminance component is corrected with the gamma correction functions to improve the dynamic range of the image, and the reflection component is corrected using the influence factor to enrich its hierarchy and enhance the overall outline of the image. Then, the Bayes threshold is used to isolate noise in the high-frequency part, the adaptive fractional differentiation can be used to enhance the details of the edges and textures of the image. Finally, NSCT reconstructs the processed image. The experimental results show that the contrast, sharpness and information entropy of the algorithm in this paper are improved by 10.7%, 9.8%, and 2.3% on average compared with the existing enhancement methods. The enhanced image is also superior to existing algorithms in terms of details and edge preservation, which improves the overall visual effect of the image.关键词：low illumination images;image enhancement;NSCT transform;Retinex;adaptive fractional differential
- 363
- |
- 23
- |
- 8
发布时间：2020-07-05 - 摘要：In order to ensure the security of some digital images with important value in untrusted channels, an image steganography algorithm based on cascaded chaotic map and low-bits embedding is proposed. The algorithm has a permutation-confusion-low bits embedding structure. In the permutation step, a novel chaotic map is firstly designed by cascade of two chaotic maps and used to generate a highly random sequence of random numbers, and then the random number sequence is used for scrambling digital images. In the confusion step, the confusion of the pixel values in the scrambling image is achieved by the XOR operation of the randomly selected cover image and the scrambling image. Finally, in the low bits embedding step, the image generated by the confusion step is split into four sub-images and embedded in the lowest two bits of the cover image. In the test of several chaotic map performance indicators, the cascaded chaotic map proposed in this paper is excellent. In the image security and performance analysis experiments, the image steganography algorithm proposed in this paper also shows high security and high execution efficiency.关键词：chaotic map;image steganography;low bits embedding
- 357
- |
- 16
- |
- 0
发布时间：2020-07-05 - 摘要：In view of the slow convergence and poor stability of traditional deep convolutional generation networks, this paper combines the Connaught kernels of multiple directions of Canny operator and Prewitt operator on the basis of traditional deep convolution generation confrontation network. To initialize the input picture parameters and reduce the training time, the training is divided into three stages, each stage adopts a different loss function, thereby improving the convergence speed and recognition effect of the network and then discriminating the volume in the network after training. The neural network is used to extract image features. The experiments of LFW and CIFAR-100 prove that the proposed algorithm is highly feasible and effective, and provides a useful reference for generating anti-network applications in the field of image recognition.关键词：generate confrontation network;deep convolution;feature extraction;computer vision
- 361
- |
- 36
- |
- 1
发布时间：2020-07-05 - 摘要：In order to realize the classification and recognition of object state, the Inception V3 module on the basis of GoogLeNet is optimized Using Tanh as the activation function and RMSprop, the SGD optimizer improves the accuracy of the model. Firstly, using cubic convolution interpolation, GAN preprocesses the image set. Then, the Inception is used to train the image. Finally, the SGD optimizer is combined with RMSprop to optimize the model. Experiments on the images of 20 cooking objects using the model proposed in this paper show that the optimized Inception V3 model can classify the state of these images with 71.5% accuracy. Compared with the comparison algorithm, the classification accuracy and training loss are obviously improved, which can meet the requirements of reliability and stability of image classification.关键词：feature extraction;image recognition;convolutional neural network;model training
- 359
- |
- 18
- |
- 3
发布时间：2020-07-05 - 摘要：In order to save the time of artificial crack identification and improve the efficiency of concrete detection, the convolution neural network image detection model is established by MATLAB. The influence of image reconstruction sampling rate, binary threshold and three detection operators (Laplace operator, Sobel operator and Canny operator) on concrete crack detection are studied. By adjusting different parameters, it can be concluded that the optimal sampling rate is 0.3 and the optimal threshold is 0.4 for the concrete crack image. Canny operator has the best effect on edge detection and crack detection, and can comprehensively reflect the edge crack situation, followed by Sobel operator, the effect of Laplace operator is poor. The convolution neural network image detection model can provide technical methods for the detection of concrete structures in complex environment in the future.关键词：MATLAB;convolution neural network;concrete;detection
- 440
- |
- 30
- |
- 2
发布时间：2020-07-05
Image Processing
- 摘要：The system is designed mainly for mobile LCD modules with a size of 7.62~20.3 cm (3~8 in) with image processing as the core based on machine vision. The visual positioning system is integrated to achieve the fully automatic detection of various types of module defects. Based on the cooperation of the positioning module and the motion control module, the positioning vision software is used to precisely control the position of the module connector and realizes the automatic docking of the connecting fingers with an alignment accuracy less than 0.03 mm. The array CCD is used to collect the images after the LCD module is lit up. The visual inspection software extractes the ROI area and performed preprocessing such as Gabor filtering, double threshold binarization and image denoising. The two-dimensional histogram oblique division method is used to locate the edge area of images for blur enhancement, and the defect properties is calculated. The defect detection has a defect recognition rate greater than 95%. The designed LCD module automatic optical inspection system can not only reduce the production costs and return rates, but also simplify the production line applications, provide a certain reference value for the development of defect detection systems for the LCD module assembly industry.关键词：automated optical inspection;surface defects;machine vision;LCD module
- 395
- |
- 53
- |
- 1
发布时间：2020-07-05
Optical Engineering
- Address：No.3888 Dong Nanhu Road, Changchun, Jilin, China 130033 Postal code：130033
- Tel：0431-86176059 Email：yjxs@ciomp.ac.cn
- Technical support is provided by Beijing Founder electronics co., LTD 吉ICP备11002662号-17
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0