- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE 2018 41st International Conference on Telecommunications and Signal Processing (TSP) - Athens, Greece (2018.7.4-2018.7.6)] 2018 41st International Conference on Telecommunications and Signal Processing (TSP) - Measurement of Relative Position of Camera and Optical Beacon by Simultaneous Passive Method
摘要： The paper deals with a problem of a passive measurement of the relative position of an optical beacon and an optical camera by a simultaneous analytical method. The beacon is composed of nine light sources which are arranged in space in a defined way. The proposed beacon layout enables the measurement of the beacon range and one position angle of the camera. This paper presents the mathematical model of the measurement method and the results, which were gathered on the basis of the experimental measurements. The standard commercial camera and lenses with four different focal lengths were used.
关键词： simultaneous passive method,optical camera,optical beacon,measurement,lens focal length,relative position
更新于2025-09-23 15:22:29
-
A polarisation-free blue phase liquid crystal lens with enhanced tunable focal length range
摘要： A polarisation-free blue phase liquid crystal (BPLC) lens with enhanced tunable focal length range is proposed. A matched conventional glass lens is introduced on a BPLC lens to increase the range of the tunable focal length. The focal length of the BPLC lens can be switched from positive to negative, the negative lens-like phase profile can be neutralised by the conventional glass lens to get an infinity focal length and the positive lens-like phase profile can be enhanced by the conventional glass lens to get a shorter focal length. The minimum focal length can be decreased to almost half of that after the proposed method is adopted in our simulation. Moreover, the proposed BPLC lens exhibits a good polarisation-free feature and the optical effect is relatively good.
关键词： tunable focal length,blue phase,polarisation-free,Liquid crystal lens
更新于2025-09-23 15:21:21
-
Technique for constructing hemispherical dielectric lens antennas
摘要： Hemispherical dielectric lens antennas can be designed to present multifunctional operation. Simple and efficient mathematical modeling to design these structures is presented. The constructing technique is based on the lens material and the desired operational frequency of the dielectric lens antennas. The analytical developed model was compared with both complete wave numerical simulations and practical experiments. The results indicate that the proposed equations to build hemispherical dielectric lens antennas are adequate for different operational frequencies and also for different dielectric lens materials.
关键词： analytical model,lens reflections and resonances,dielectric lens antenna,focal length,gain
更新于2025-09-19 17:15:36
-
[IEEE 2018 IEEE International Conference on Electro/Information Technology (EIT) - Rochester, MI (2018.5.3-2018.5.5)] 2018 IEEE International Conference on Electro/Information Technology (EIT) - Framework for Simulating and Rem,/Oving Rain in Stereo-Image Videos
摘要： We present an implementation of a rain simulation and rain removal framework, which is based on video streams captured with a stereo camera system. This framework can be used to study the effect of rain on vision-based systems in the automotive domain, including obstacle detection, vehicles tracking and traffic sign recognition. We also present testing techniques, to verify the performance of rain simulation/ removal systems, and quantify the closeness of de-rained image to the original rain-free image.
关键词： Simulated rain,rain density,rain streaks,stereo-vision,de-raining,focal length
更新于2025-09-10 09:29:36
-
Ultra-fast adaptive optical micro-lens arrays based on stressed liquid crystals
摘要： We characterized the optical properties of a photoresist-based micro-lens using a stressed liquid crystal matrix for high-speed variation of the focal distance. We also determined the operational parameters for the adaptive optical spherical and cylindrical micro-lens arrays. The resulting optical elements feature fast response times, around 1 ms, with a focal length range of 2600-970 μm.
关键词： stressed liquid crystals,adaptive optical micro-lens arrays,focal length variation,fast response times
更新于2025-09-09 09:28:46
-
Electrically Tunable Binary-Phase Fresnel Lens Based on Polymer Dispersed Liquid Crystal
摘要： This is a proposal for a Fresnel lens with an electrically tunable binary-phase made of polymer dispersed liquid crystal (PDLC), which has relatively fast response time and low applied voltage. Simple fabrication is the major advantage of the proposed method. In this study, NOA65 and E7 were utilized with weight ratios of 60 wt.%: 40 wt.%. There was also the utilization of a relatively low intensity UV-light, 0.53 mW/cm2. The duration time of exposure was about 30 hours. The performance improvement of the Fresnel lens resulted from the infiltration of large LC droplet into the PDLC film. The phenomenon of black cross strip patterns could be explained with the use of the electro-hydrodynamics theory. The diffraction efficiency of the proposed lens was from 31.1 % to 41 % with the changes of externally applied voltage. This work presents an effective approach to get relatively complete phase separation in PDLC. The proposed method also provides great potential in developing high performance Fresnel lens.
关键词： binary-phase Fresnel lens,electrically tunable focal length,phase separation,polymer dispersed liquid crystal
更新于2025-09-04 15:30:14