Electro-Optic Technology Application
Co-Editors-in-Chief
Bing Han

Jan. 01, 1900
  • Vol. 29 Issue 4 1 (2014)
  • ZHAO Liang

    Based on the geometrical optics theory of three-reflection optical system, the design method of the system is discussed in detail. According to primary aberration theory, a calculation formula of the three-reflection system initial structure is deduced. And the relationships among system structure, basic structure parameters and focal length are obtained. The characteristics and the applications of three-reflection optical systems are discussed through design examples. The optical system with wide field of view, small F number and diffraction limit imaging is designed to suppress stray light effectively.

    Jan. 01, 1900
  • Vol. 29 Issue 4 1 (2014)
  • XIE Su-juan

    The remote control IR receiver PCB in traditional TV parallels to the display panel at vertical direction, and the bezel size is larger. For resolving the problem and meeting the requirement of TV with super narrow bezel, at the condition of moving PCB to the back of the panel and no occupying TV down bezel space, the IR reception lens is designed to receive remote control signals from long-range and multi-angle effectively. And super narrow bezel can also be realized on down bezel. According to geometrical optics total reflection principle and refraction law, the designed lens is simulated and analyzed by Tracepro software. The defects in lens design are checked, and then the lens structure contour is adjusted and revised. And the optimized lens structure is obtained. The results show that when IR PCB face indirectly to lens window, IR receiver can also receive effective light flux at the condition of changing the partial structure of the lens, which meets or exceeds to TV remote control test standard. The design targets of super narrow down bezel or complex and diversity appearances are realized by the optimization design.

    Jan. 01, 1900
  • Vol. 29 Issue 4 5 (2014)
  • WANG Jia-yi

    A mathematical modeling method of an off-axis double-reflection laser beam expander is described. At the condition of input a few special parameters, all the parameters on the main operation panel of the beam expander are calculated. With the calculation software such as MATLAB and EXCEL, the initial structure of all the operation panels of the beam expander is obtained easily. We can judge directly with the method whether the initial structure accords with the requirements of system assembling and debugging or not. It has the characteristics of convenience method and fast speed calculation.

    Jan. 01, 1900
  • Vol. 29 Issue 4 10 (2014)
  • CHEN Ke-wei

    Optical surface accuracy is an important index to determine whether optical components accord with requirements. Peak-to-valley (PV) value used as an evaluation standard is the difference between the highest point and the lowest point of the surface. PV value detected by UA3P detector has great variation, which is easy to be affected by environment. In order to evaluate the accuracy of mobile phone lens aspheric surface more effectively, three evaluation standards of PV, PV20 and PVq to reflect the actual surface are discussed through experiments. The results show that PV20 and PVq are relatively insensitive to environment factors and the adverse effects on measurement results from singular points such as dirty points can be eliminated to some extent. Meanwhile, it is proved that PV20 and PVq are relatively insensitive to detection accuracy variation and they have better evaluation stability in batch production.

    Jan. 01, 1900
  • Vol. 29 Issue 4 13 (2014)
  • LIU Guo-quan, MA Dong-liang, YANG Da-feng, and WEI Ya-xing

    Charcoal is an important oxidation foaming agent in the preparation of inorganic open-cell foam wave-absorbing material. And it is a good wave-absorbing agent added to sample preparation process. The foam samples with different charcoal volume content such as 0.1%, 0.5%, 1.5%, 2% and 3% are prepared at laboratory. The dielectric constant of the five samples is measured and the reflectivity of the samples at X wave band is calculated on theory. Through test measurement, the conclusion is obtained that the best character is got when charcoal content is 3% during the preparation of inorganic open-cell foam wave-absorbing material, which provide reference for material preparation.

    Jan. 01, 1900
  • Vol. 29 Issue 4 17 (2014)
  • ZHANG Sheng-dong, WANG Feng-chao, and ZOU Jun

    Three kinds of YAG phosphor is chosen from a famous phosphor enterprise in China as research objects. The samples have same laser spectrum and central particle sizes (D50) are 9.3 μm, 13.6 μm and 16.7 μm respectively. At the condition of same filler-asphalt mass ratio and bonding volume, with the phosphor and 3014 type stand, white light LED lamp bead samples are produced. Optical parameters of the samples before and after aging are measured respectively by a spectrophotometer. Test results show that with the increasing of the center particle size of phosphor, color temperature approaches to the direction of high color temperature. When color temperature is constant, with the increasing of center particle size, luminous flux increases. Luminous decay reduces gradually with the increasing of phosphor particle size at the condition of one week accelerating aging time and 100 mA current.

    Jan. 01, 1900
  • Vol. 29 Issue 4 21 (2014)
  • HUANG Wei-ming, WEN Shang-sheng, and CHEN Ying-cong

    A new encapsulating mode for LED luminaire is introduced. Dual channel heat-dissipation effect is obtained by using high thermal conductive glass shell and inert gas to encapsulate instead of traditional epoxy resin and using plastic heating-radiator instead of traditional aluminum substrate. The thickness of inert gas layer is optimized with ANSYS finite element thermal analysis software. Thermal simulation results are compared and analyzed through changing the number of LED, the power of a single LED and traditional ceramic substrate chip on board (COB) encapsulation mode. Research results show that heat-dissipation effect is better when the thickness of inert gas layer is 1.5 mm and the thermal resistance of dual channel heat-dissipation luminaire is far less than that of single channel. Comparing with traditional epoxy resin, plastic has the characteristics of high transmissivity, anti-aging and good anti-ultraviolet effect. The new encapsulation mode has widely application prospect in the market enviroment of widely development of UV LED luminaire with high power and intensive encapsulation.

    Jan. 01, 1900
  • Vol. 29 Issue 4 24 (2014)
  • GUO Ling, and ZHU Mao-zhi

    Detecting light stripe center position accurately has critical consequences for the accuracy of the structured light measurement system. A robust method which extracts the light stripe center by multi step is proposed. Firstly, the noise points are moved by adaptive thresholds. Then, the initial centers of light stripes are obtained using expansion and thinning algorithm. After that, those initial centers’ normal direction can be gained with their gradient. At last, the sub-pixel center line of structured light is obtained by computing the gray-gravity along the stripe’s normal direction. The method applied to a tunnel contour deformation detection system which measuring principle is linear structured light. The test results showed that the method can accurately extract the center line.

    Jan. 01, 1900
  • Vol. 29 Issue 4 30 (2014)
  • HUANG Chong, XU Guo-dong, YANG Wei-feng, OUYANG Yan-dong, and WU Yong-jun

    The electro-optical characteristics of negative VA-LCD driven by different voltage are measured by UV-Vis8500 double beam ultraviolet (UV)/ visible spectrophotometer. The threshold characteristics of three primary colors and the characteristics variation with wavelength are analyzed. The results show that threshold voltage (Vth), saturation voltage (Vsat) and mid-value voltage (V50) all increase gradually with the increasing of wavelength. And the difference between Vsat and Vth becomes larger gradually with the increasing of wavelength. Common used mean voltage V50 of three kinds of central wavelength such as 500.0 nm, 550.0 nm and 600.0 nm is taken as driving voltage to analyze. The results can provide certain guidance for choosing the driving voltage of colorful liquid crystal display (CLCD).

    Jan. 01, 1900
  • Vol. 29 Issue 4 34 (2014)
  • SHAO Guo-feng, LIN Jin-shun, and ZHANG Wei-guo

    A fast multi-focus image fusion algorithm based on lifting wavelet transform is introduced. Firstly, the original images are decomposed into four sub-bands such as LL, LH, HL and HH through the algorithm. And then, high frequency details sub-bands such as LH, HL and HH representing three directions are performed lifting wavelet inverse transform to obtain high frequency details images of sub-bands on all directions. Non-uniform weighted area energy of obtained high frequency detail images is calculated through Gaussian kernel weight algorithm. And the final fusion images are obtained according to image fusion rule based on energy. Comparing with the characteristics of multi-focus image fusion schemes, experimental results show that the method is more effective than present methods on processing speed at the condition of same fusion effect.

    Jan. 01, 1900
  • Vol. 29 Issue 4 39 (2014)
  • WANG Pei-li

    According to the problem between real-time image processing and mass data, dual-port random access memory (RAM) used in image processing system is presented. The functions and characteristics of dual-port RAM are introduced. Taking IDT70V09 chip as an example, system structure, hardware interface, system software design of dual-port RAM used in image processing system and the detailed design of dual-port RAM operation software of field-programmable gate array (FPGA) and data signal processor (DSP) are given. And the port contention problem of dual-port RAM and the solutions are discussed in detail. The suggestions about printed circuit board design and circuit debugging of the system are proposed. Finally, function test of the image processing system is performed to prove the stability and feasibility of the system adopting dual-port RAM design.

    Jan. 01, 1900
  • Vol. 29 Issue 4 45 (2014)
  • ZHANG Sheng-chong

    The principle of IR image pseudo-color display, coding algorithm and hardware structure are introduced. Three kinds of red, green and blue (RGB) mapping functions from dark (black) to bright (white) are designed, which correspond to the temperature of the infrared images from low to high. Pseudo-color image display with distinct color, outstanding image detail and more suitable to human eyes observation is realized. The real-time variable pseudo-color transform algorithm and video coding output are realized through FPGA+TMS320C6416DSP+SAA7199B digital video encoding chip, and the effectiveness of system software and hardware is verified.

    Jan. 01, 1900
  • Vol. 29 Issue 4 50 (2014)
  • LIU Chen, LIU Chun-zi, and WAN Hong

    For analyzing quantitatively the subjective feeling of people and vision comfort during driving, the analysis and evaluation method of the lighting quality of automotive headlamps and the impact of light quality on human eyes subjective feeling are described. In the experiment, the light intensity data of automotive headlamps is obtained through light fitting machine. The method of calculating luminous flux, ground illuminance and brightness by using the data is introduced in detail. The advantage and disadvantage analysis of automotive headlamps lighting quality through calculation are obtained. The correctness of the calculation method is verified in simulation. And the brightness correction for human eyes feeling is added to ground brightness simulation to get a better human eyes feeling. So it has an important meaning to automotive lamp production.

    Jan. 01, 1900
  • Vol. 29 Issue 4 61 (2014)
  • MA Xiao-hang, ZHU Ting-ling, and BIAN Xin-tian

    A method to measure the three-dimensional (3D) surface figure based on three step phase-shifting is proposed. Firstly, the grating projected by a projector is pre-corrected to assure standard sinusoidal fringe projected on the reference surface. Secondly, three frames of grating with same phase-shifting are projected on the surface of the tested object by a projector during measurement. Three frames of deformation fringe patterns are captured by a CCD camera and the phase is extracted from a phase calculation model. Finally, the 3D surface figure of the tested object can be reconstructed by height mapping formula. The method has stronger anti-noise ability, measurement process can still be performed in large noise environment, which lay a foundation for dynamic on-line measurement. The feasibility of this method is verified by simulations and initial experiments.

    Jan. 01, 1900
  • Vol. 29 Issue 4 65 (2014)
  • YIN Yan-he, QIAO Yan-feng, CAI Sheng, and QIAO Guan-yu

    According to the reasons of three-dimensional (3D) angle deformation of large structure in engineering applications and measurement requirements, the research states of optical small angle measurement method used in engineering area are described and analyzed. Some methods such as auto-collimation, polarization light, light source target, moiré fringe, image shape deformation and photography and videography are introduced. Comparing with the characteristics of the methods, the problems and development of optical 3D angle deformation measurement technology are discussed.

    Jan. 01, 1900
  • Vol. 29 Issue 4 69 (2014)
  • LI Yue-qin, PEI Li, NING Ti-gang, WANG Yi-qun, YUAN Jin, and LI Jing

    Microwave photonic-assisted instantaneous frequency measurement (IFM) system has many advantages such as high time-bandwidth product, low power consumption, light weight and anti-electromagnetic interference. Domestic and foreign IFM systems are introduced respectively according to three kinds of mapping modes such as frequency-space, frequency-time and frequency-amplitude. And IFM system with frequency-amplitude mapping relationship is mainly concluded and compared. According to the trade-off problem between measurement range and accuracy, IFM researching technology with high accuracy and tunable measurement range is further presented. And the current researches in the fields are reported.

    Jan. 01, 1900
  • Vol. 29 Issue 4 76 (2014)
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