最新刊期

    40 3 2025

      Device Physics and Device Preparation

    • 在液晶器件领域,专家提出了基于导电层与取向层的多层减反射膜设计方法,实现了高透过率,为高能量利用率、高稳定性液晶器件提供解决方案。
      DIAO Zhihui, ZHAO Huiru, PENG Zenghui, LIU Yonggang, MU Quanquan
      Vol. 40, Issue 3, Pages: 393-399(2025) DOI: 10.37188/CJLCD.2024-0298
      摘要:Conductive layer and alignment layer are the most common and important film structures in liquid crystal devices. The two film layers are located between the substrate and the liquid crystal, and the film transmittance decreases due to the refractive index mismatch problem, which reduces the light energy utilization rate of the liquid crystal device. To address this problem, this paper proposes a multi-measurement anti-reflection film design method based on conductive layer and alignment layer, and uses the conductive layer and alignment layer as a link in the film system to achieve high transmittance. First, a physical model of a multilayer anti-reflection film based on conductive layer and alignment layer is constructed. Then, based on this model, the corresponding film structure is theoretically designed to achieve high transmittance of the film. Finally, the influence of the liquid crystal power-on process on the film transmittance is systematically studied. The results show that the transmittance of the designed anti-reflection film remains above 99% in the 500~800 nm band and above 96% in the 400~500 nm band; driving the liquid crystal will cause the film transmittance to decrease. Based on the mixed refractive index of the liquid crystal, the transmittance decrease can be reduced to less than 0.5%. This study will be conducive to the realization of liquid crystal devices with high energy utilization and high stability.  
      关键词:conductive layer;alignment layer;anti-reflection   
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    • Equal power beam splitter based on liquid crystal polymer waveguides AI导读 wxIcon

      科技媒体新闻记者报道:研究者开发出基于液晶高分子薄膜的等功率分束器,实现了光的并行传输与等功率分配,为光计算和光通信等领域提供新解决方案。
      WANG Zhaoyi, CHENG Hongbo, HU Honglong, YUAN Conglong, ZHENG Zhigang
      Vol. 40, Issue 3, Pages: 400-406(2025) DOI: 10.37188/CJLCD.2024-0333
      摘要:This study proposes a liquid crystal polymer-based equal-power splitter. Through multi-angle polarized patterned photoalignment, precise control of liquid crystal molecular orientation in a two-dimensional plane was achieved, enabling the fabrication of a 1×2 equal-power splitter based on a Y-shaped splitter model. By optimizing the bending radius of the waveguide, two types of splitters with spacing of 80 μm and 160 μm were developed. Furthermore, these splitters were cascaded to construct a 1×4 equal-power splitter with uniform spacing. Experimental results demonstrate that parallel light transmission and equal-power distribution within the liquid crystal waveguides are achieved, providing an effective solution for enhancing the functionality of liquid crystal waveguide devices. This research offers a new approach for advancing the integration and miniaturization of liquid crystal polymer waveguides, with potential applications in optical computing and optical communication.  
      关键词:liquid crystal polymer;waveguide;equal power splitting;photoalignment   
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    • Overview of active terahertz metasurface devices based on liquid crystal AI导读

      在太赫兹技术领域,液晶超表面的研究取得进展,展示了对太赫兹波振幅、频率、相位和偏振态的动态调控能力,将推动太赫兹在成像、通信和传感领域中的应用。
      SHEN Yanchun, XU Yaqian, HU Wei
      Vol. 40, Issue 3, Pages: 407-423(2025) DOI: 10.37188/CJLCD.2024-0320
      摘要:Metasurface devices greatly enrich the interaction between light and matter, promoting the development of planar optics. In recent years, with the rapid development of terahertz (THz) technology, dynamically tunable terahertz devices have been widely studied. Liquid crystal (LC) is a unique soft matter that combines the fluidity of liquids and the order of crystals, making it indispensable in the field of displays and spatial light modulations. The integration of liquid crystals and metasurfaces enables tunable terahertz devices. In this review, we summarize three types of liquid-crystal based terahertz metasurfaces and their research progress, including liquid crystal planar terahertz devices, liquid crystal integrated metal metasurfaces, and liquid crystal integrated dielectric metasurfaces. Furthermore, techniques for fabricating liquid crystal microstructures as well as liquid-crystal integrated metal or dielectric metasurfaces are introduced. Due to the excellent responsiveness of liquid crystal metasurfaces to external stimuli including electric fields, magnetic fields, heat and light, the amplitude, frequency, phase, and polarization state of terahertz waves are dynamically manipulated. The tunable terahertz metasurface devices based on liquid crystals drastically promote the application of terahertz in imaging, communication, and sensing fields.  
      关键词:liquid crystal;metasurface devices;terahertz;tunable devices   
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    • 在聚合物分散液晶薄膜领域,研究人员通过聚合诱导相分离技术制备PDLC薄膜,发现聚合单体EOHDDA、IBOMA、4-HBA制备的PDLC薄膜视角电光性能最佳,满足实际应用需求。
      ZHAO Xiaoxiang, LIU Lulu, WANG Yiping, LI Zhengqiang, LI Jinglei
      Vol. 40, Issue 3, Pages: 424-430(2025) DOI: 10.37188/CJLCD.2024-0322
      摘要:The electro-optical performance of the viewing angle of polymer dispersed liquid crystal (PDLC) films can exert an influence on people’s perception effect in practical applications. To optimize the viewing angle performance of PDLC films and reduce the difference in haze between the side view and the front view, thereby improving people’s actual perception, this paper conducts a study on the electro-optical characteristics of PDLC films from the perspective of polymer monomers and explores the factors affecting the viewing angle performance of PDLC. PDLC is fabricated using the polymerization-induced phase separation (PIPS) technique. The viewing angle haze values of PDLC films fabricated with bifunctional monomers, methyl-functional monomers and hydroxyl-functional monomers are tested using a haze meter, and the difference in haze between the frontal viewing angle and the lateral viewing angle of PDLC is calculated. The experimental results indicate that the PDLC fabricated with polymer monomers such as EOHDDA, IBOMA and 4-HBA, which feature a moderate alkyl chain length, a refractive index (no) matching that of the liquid crystal, and low steric hindrance, has the smallest viewing angle haze difference (ΔH), which is 2.66%. The electro-optical performance of this wide-viewing-angle PDLC film is the best, with the smallest viewing angle difference and the optimal visual effect,which can meet the needs of practical applications.  
      关键词:polymer dispersed liquid crystal;polymeric monomer;viewing angle performance;refractive index   
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    • Influence of optical film on the color change of LED backlight AI导读

      科技媒体新闻记者报道,最新研究显示,Mini LED背光显示产品通过光学扩散板和复合膜实现亮度和均匀性提升,复合膜显著改变背光色坐标和亮度参数。
      ZHONG Wenkui, LIN Weihan, YANG Meihui, HU Wendang, XIE Peichuan
      Vol. 40, Issue 3, Pages: 431-438(2025) DOI: 10.37188/CJLCD.2024-0275
      摘要:Mini LED backlight display products use optical diffusion plates and composite films to improve brightness and uniformity. The test results of this paper show that the brightness gain of composite films ranges from 1.5 to 2 times, with the order of brightness gain being POP>DPP>MOP>DOP. This is due to the correction effect of different composite films on the beam solid angle. At the same time, the composite film raised the backlight color coordinates, with the change in the diffusion plate+DPP color coordinates being Δx of 0.01 and Δy of 0.018 7. Analysis shows that the significant loss of short wavelength blue light radiation energy is caused by Mie scattering of diffusing particles. The blue light reflected back from the multi-layer optical microstructure of the composite film to the quantum film will generate multiple photoexcitation phenomena, further increasing the amplification of the xy color coordinate values of the quantum dot model by the composite film. The color coordinate changes generated by the optical composite film are beneficial for adjusting the color temperature of the display product to a lower color temperature from the factory to ensure display brightness.  
      关键词:mini LED;optical film;scattering;refractive reflection;color coordinates   
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    • Mura defect detection of LCD screen based on improved YOLOv8n AI导读

      在液晶屏Mura缺陷检测领域,研究人员提出了基于改进YOLOv8n的YOLO-D3MNet模型,有效提升了检测精度,为解决Mura缺陷检测问题提供新方案。
      CHEN Shunlong, LIAO Yinghua, LIN Feng, SHU Chengye
      Vol. 40, Issue 3, Pages: 439-447(2025) DOI: 10.37188/CJLCD.2024-0295
      摘要:To address the problem of insufficient accuracy in LCD Mura defect detection due to low contrast and diverse scale differences, from the perspective of improving the model’s performance in detecting small-scale defects and weak defects, an improved YOLOv8n-based LCD Mura defect detection model, YOLO-D3MNet, is proposed. Firstly, the backbone and neck networks of the model are reconstructed through the introduction of the ConvNeXtv2 module, which improves the weak feature extraction capability of the model under the background of complex texture. Secondly, for the problem of insufficient cross-channel communication of feature information in the detection head module, an efficient decoupling head combining the channel shuffle strategy and depth-separable convolution is proposed to promote the information flow between different feature channels and reduce the model computation power requirement. Finally, to address the problem that the intersection and concatenation ratio metric based on prediction box and truth box is sensitive to the positional bias of small-scale defects, the normalized Gaussian Wasserstein distance loss function is introduced to provide more positive sample candidate boxes, which improves the model’s detection performance of Mura defects. The precision, recall and mAP50 of the improved YOLO-D3MNet model are 92.9%, 88.8% and 94.8%, respectively. Compared to the base model YOLOv8n, the precision, recall and mAP50 of the YOLO-D3MNet model are improved by 3.4%, 2.7% and 3.6%, respectively, while the GFLOPs of the model are reduced by 24.7%. Compared with mainstream target detection models such as YOLOv5n, the experimental results show that the YOLO-D3MNet model proposed in this paper has better performance in LCD Mura defect detection.  
      关键词:Mura defects;LCD screen;object detection;deep learning;weak feature   
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      Circuit Design

    • Design of heterogeneous FPGA hardware accelerator based on CNN AI导读

      在硬件设计领域,专家提出了一种基于SoC的异构嵌入式系统设计,有效提升了CNN网络的功率效率,为节能高效硬件设计提供新方案。
      JI Haolin, XU Wei, PIAO Yongjie, WU Xiaobin, GAO Tan
      Vol. 40, Issue 3, Pages: 448-456(2025) DOI: 10.37188/CJLCD.2024-0198
      摘要:Due to limitations in hardware platform computing power and storage resources, achieving energy-efficient and efficient convolutional neural networks (CNNs) by using embedded systems remains a primary challenge for hardware designers. In this context, a complete design of a heterogeneous embedded system implemented by using a system-on-chip (SoC) with a field-programmable gate array (FPGA) is proposed. This design adopts a cascaded input multiplexing structure, enabling two independent multiply-accumulate operations in a single DSP, reducing external memory access, enhancing system efficiency, and lowering power consumption. Compared to other designs, the power efficiency is improved by over 38.7%. The design framework is successfully deployed in a large-scale CNN network on low-cost devices, significantly improving power efficiency of the network model. The power efficiency achieved on the ZYNQ XC7Z045 device can even reach 102 Gops/W. Furthermore, when inferring the VGG-16’s CONV layers by using this framework, a frame rate of up to 10.9 fps is achieved, which demonstrates the framework’‍s effective acceleration of CNN inference in power-constrained environments.  
      关键词:hardware acceleration;convolutional neural network;FPGA;heterogeneous SoC   
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      Image Processing

    • Estimation method of category-level multi-object rigid body 6D pose AI导读

      在6D位姿估计领域,本研究提出了一种单阶段多目标网络架构,有效提升了遮挡物体场景下的位姿估计性能,为多目标位姿估计提供了新解决方案。
      CHENG Shuo, JIA Di, YANG Liu, HE Dekun
      Vol. 40, Issue 3, Pages: 457-471(2025) DOI: 10.37188/CJLCD.2024-0182
      摘要:In order to solve the problems of poor scalability, low generality and high computational cost of the traditional method using single object CNN model, and optimize the performance of multi-objective method. In this paper, a single-stage network architecture for multi-objective 6D attitude estimation is proposed, and a multi-branch feature extraction decoder is designed to capture and aggregate detailed features effectively. This paper proposes a feature optimization and screening module, which filters input features to extract multi-scale features. Combining the above two, a new feature pyramid structure is designed to improve the overall performance of the network and improve the pose estimation effect of occlusion. The experiments are carried out on synthetic data set LINEMOD and Occluded LINEMOD. The results show that the proposed method has achieved significant improvement in the processing of blocked object scenes. Compared with the most advanced methods such as PyraPose, SD-Pose and CASAPose, the proposed method has increased the ADD/S-Recall index by 43.1%, 16.1% and 12%, respectively. It performed better when the number of targets is small, increasing performance by 17% when the number of targets is 4. The ablation experiment further verifies the effectiveness of each module. By introducing multi-branch feature extraction decoder, feature optimization and screening module, and feature pyramid structure, the proposed single-stage multi-objective network architecture can process any number of targets by training only one network, and can perform 6D pose estimation better under the condition of synthetic data. Experimental results verify the effectiveness of the proposed method.  
      关键词:6D pose estimation;multi-objective single-stage network;multi-drop feature extraction layer;feature selection;composite data   
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    • 在无人机航拍图像目标检测领域,提出了一种新方法,有效提升了轻量级目标检测模型性能。
      JIN Liwei, XU Wangming, LI Yaoxiang
      Vol. 40, Issue 3, Pages: 472-480(2025) DOI: 10.37188/CJLCD.2024-0225
      摘要:In order to address the problem of missed and false detections caused by different object scales, densities, unclear details and especially numerous small objects in drone aerial images, a novel object detection method based on Adaptive Slicing Aided Inference (ASAI) is proposed. Firstly, an aerial image is input into an object detection network for initial inference. With the initial inference results, a window scoring mechanism is designed to locate the ambiguous targets in the input image, and the effective image regions are selected automatically for slicing to adapt to objects with different scales and densities. Then, the sliced images are sent to the object detection network for secondary inference. Finally, the two inference results are processed by an improved non-maximum suppression (NMS) algorithm to obtain the final detection result. Experimental results on typical datasets of VisDrone2019 and AI-TOD indicate that the proposed method improves the mAP metrics of typical lightweight object detection models including YOLOv7-tiny, YOLOv8n, YOLOv8s and YOLOv9-C, effectively improving the performance of object detection for aerial images.  
      关键词:small object detection;adaptive slicing aided inference;ambiguous target localization;Non-maximum suppression   
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    • 在水下图像增强领域,研究者提出了基于Retinex的可变注意力框架,有效提升低照度图像清晰度,为水下视觉研究提供新方向。
      TAO Yang, GONG Jiting, ZHOU Liqun
      Vol. 40, Issue 3, Pages: 481-492(2025) DOI: 10.37188/CJLCD.2024-0165
      摘要:To address issues of insufficient illumination and complex degradation caused by underwater scattering in low-light underwater image enhancement tasks, we propose a Retinex-based variable attention framework. An illumination-guided variable attention module is designed, which uses semantic information from brightness feature maps to enhance dark regions and improve the adaptive enhancement capability of the model. We construct a spatial-frequency domain feature fusion module, which enhances the prominence of image texture information through multi-scale feature extraction and inter-level feature fusion. A medium transmission module is introduced to further address image artifacts caused by underwater scattering during enhancement. The experimental results show that compared with other cutting-edge methods, our method has significant improvements in four objective indicators, with PSNR reaching 22.781 8, SSIM reaching 0.882 1, UCIQE reaching 0.614 6, and UIQM reaching 3.365 9. The enhanced images exhibit excellent visual quality, validating the effectiveness of our algorithm in improving the clarity of low-light underwater images.  
      关键词:underwater image enhancement;low illumination;Retinex;variable attention   
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    • 在点云配准领域,研究者提出了一种高效算法,显著提升了配准精度和效率,为不同场景下的应用提供了解决方案。
      LI Junjie, LEI Chen, LI Weicheng, YU Xiaohui, YANG Yuhan, ZHU Wenli
      Vol. 40, Issue 3, Pages: 493-504(2025) DOI: 10.37188/CJLCD.2024-0184
      摘要:In response to the problems of weak applicability, low registration efficiency and poor robustness of existing point cloud registration algorithms when registering point clouds from different scenes, this paper proposes an efficient registration algorithm for models, indoor scene and outdoor scene point clouds. Firstly, voxel grid filtering is used to downsample the point cloud, and intrinsic shape signatures (ISS) is used to extract point cloud features. Then, fast point feature histograms (FPFH) are used to describe the feature points, and random sample consensus (RANSAC) algorithm is used for rough registration of point clouds. Finally, the voxelized generalized iterative closest point (VGICP) algorithm accelerated by a graphics processing unit (GPU) is used to achieve precise registration. Experimental results show that in the three-dimensional model, indoor and low overlap outdoor point clouds with noise, the proposed algorithm achieves high registration accuracy while only consuming 0.118 s, 0.306 s, and 0.648 s, respectively. Compared with existing registration algorithms, the registration efficiency is improved by 79.12%, 82.41%, and 88.28%, respectively. The proposed algorithm has high registration accuracy and efficiency in different application scenarios, and has stronger applicability and higher robustness.  
      关键词:point cloud registration;random sample consensus;graphics processing unit;voxelized generalized iterative closest point   
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    • Dense pedestrian detection algorithm based on YOLOv7 with optimized weights AI导读

      在行人检测领域,研究者提出了基于优化权重的YOLOv7算法,有效提升了密集人群中的检测精度。
      CAO Jie, NIU Yu, LIANG Haopeng
      Vol. 40, Issue 3, Pages: 505-515(2025) DOI: 10.37188/CJLCD.2024-0175
      摘要:Aiming at the problem of poor detection accuracy caused by pedestrian crowding and occlusion in natural complex scenes, a dense pedestrian detection algorithm based on YOLOv7 with optimized weights is proposed. First, to address the occluded pedestrian feature extraction problem, the weights of the backbone network are redistributed by the algorithms for typical geometric figures of rectangle and circle. Measuring principles and algorithms of typical plane cross-space efficient multi-scale attention module with cross-spatial learning (EMA), and the correlations between different channel features are learned cross-dimensionally, which can enhance the model’s attention to the visible area of the pedestrian target. Second, to address the problem of high complexity of the detection model, the efficient lightweight connection module (ELCM) is designed to improve the model representation ability and speed up the training speed. Finally, a focused bounding box loss function, Focal-SIoU loss, is constructed, which focuses on suppressing low-quality samples and adds angular loss to improve the detection accuracy of the model. Experimental results demonstrate that the proposed algorithm achieves mean average precisions of 83.7% and 82.6% on the Wider-Person and Crowd Human datasets, respectively, showing significant advantages in dense crowded pedestrian detection tasks.  
      关键词:dense pedestrian detection;optimized weights;focusing bounding box loss function;YOLOv7   
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    • Few-shot wildlife detection based on multi-scale context extraction AI导读

      在野生动物检测领域,MS-FSWD算法通过多尺度上下文提取和原型校准模块,有效提升了小样本数据集的检测精度。
      LIU Ke, LIN Shanling, SHI Xinyu, LIN Jianpu, LÜ Shanhong, LIN Zhixian, GUO Tailiang
      Vol. 40, Issue 3, Pages: 516-526(2025) DOI: 10.37188/CJLCD.2024-0168
      摘要:In order to solve the problems of difficulties and low detection accuracy caused by the small sample size and variable target scale of wildlife datasets, a few-shot wildlife detection (MS-FSWD) algorithm based on multi-scale context extraction was proposed. Firstly, the multi-scale context extraction module was used to enhance the perception ability of the model for wildlife at different scales and improve the detection performance. Secondly, Res2Net was introduced as a strong classification network of the prototype calibration module to correct the class scores output by the classifier. Then, the shuffle attention mechanism was added to the RPN to enhance the feature map of the target region and weaken the background information.Finally, using the Balanced L1 Loss as the localization loss function improves the target positioning performance.Experimental results show that compared with the DeFRCN algorithm, MS-FSWD improves the novel class AP50 by 9.9% and 6.6% respectively in the 1-shot and 3-shot detection tasks on the few-shot wildlife dataset FSWA. On the public dataset PASCAL VOC, MS-FSWD is increased by up to 12.6%. Compared with the VFA algorithm, in the 10-shot task of the PASCAL VOC dataset Novel Set 3, the novel class AP50 is increased by 3.3%.  
      关键词:few-shot object detection;wildlife detection;transfer learning;multi-scale context extraction;attention mechanism   
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