A new dimmer for alternating-current directly driven light-emitting-diode lamp

A new dimmer using a mental-oxide-semiconductor field-effect transistor (MOSFET) for alternating-current (AC) directly driven light-emitting-diode (LED) lamp was presented. The control method of proposed dimmer is pulse width control (PWM) method. Compared with the conventional phase-controlled dimmer, the proposed PWM dimmer can produce sine wave and did not cause harmonics problem. Furthermore, the proposed control method did not amplify the light flicker due to the independence of input voltage. Therefore, the PWM dimmer can be used as the dimmer of the AC LED lamp instead of the conventional phase-controlled dimmer. The experimental result shows that the proposed PWM dimmer has good performances.     

Development and Study of Applications Combining Nanopowder Imprint Lithography and Array-Type UV-Curing Technology for Micro-Lens Molding

This study developed creative imprinting technology, combining nano-imprint lithography and array-type UV-curing technology. It used nanopowders as the method to transmit imprint force, and integrated technical features, such as soft lithography, light-curing resistant and gas-assisted imprint technology, in order to study the development of technological processes of micro-lens array manufacturing, and mature the application and technology of nano-imprinting. According to research results, SUS 304 stainless steel sheet with a micro-hole array could be smoothly fabricated into an original micro-lens array mold upon gas-assisted micro-hot embossing. At the same time, a micro-lens array structure with a complementary external form could be precisely remolded and reproduced by PDMS. Complete molding of micro-lens could be effectively achieved by combining imprints of gas-assisted lithography developed in this study, and even UV-NIL. The effective imprinting area and reproducibility of transfer printing could be greatly improved when a micro-lens contacts perfectly with a substrate surface. Moreover, since PDMS soft molds have short remolding times, and are easily feathered during manufacturing, production costs could be effectively reduced through features such as, low surface free energy, resistant to adhering to the mold during imprinting, and collocation of gas-assisted nanopowder imprinting of micro-structural processes.     

发光二极管光通量的测量研究

近几年发光二极管(LED)取得了重大进展,但是由于LED的特殊性,至今国内尚未建立起一套完善的LED测量标准。正是出于这种原因,本文有针对性地对LED总光通量的测量进行了研究。     

不同光强LED黄光对滇重楼生长、光合特性和皂苷含量的影响

为探究发光二极管(LED)黄光不同光强对滇重楼光生物学特性和品质的影响,同时为LED光源在滇重楼生产上的应用提供理论依据。本研究以3年生滇重楼种苗为试验材料,采用波长为590 nm±5 nm的黄光为照射光源,设置了25、50、75、100μmol/(m~2·s)4个光强梯度处理,对滇重楼生物学鲜重、叶片光合荧光特性及根茎皂苷含量进行了研究。结果表明,75μmol/(m~2·s)处理滇重楼叶片净光合速率、荧光指标、气孔导度、蒸腾速率均为最高。25μmol/(m~2·s)处理的荧光指标最低。100μmol/(m~2·s)处理下重楼根茎皂苷含量最高,25μmol/(m~2·s)处理下皂苷含量最低。综合分析滇重楼叶片光合荧光特性和根茎皂苷含量,黄光75μmol/(m~2·s)对促进滇重楼叶片的光合作用最有利,黄光100μmol/(m~2·s)对增加滇重楼根茎皂苷含量最有利。建议在滇重楼栽培上将黄光光强控制在75~100μmol/(m~2·s)为宜。     

Design of White LED Energy-saving Street Lamp

An energy-saving light-emitting-diode（LED） street lamp was conducted, Based on the simulation by optical software TracePro, a physical street lamp system including 600 white LEDs was achieved. This system was operated under a constant current of 20 mA for each unit, and the electric power consumption of the whole lamp was only 42 W. Experimental results demonstrated that the total average illuminance reached 8.8 lx and the overall uniformity was 0. 370 for a 30-m-long and 10-m-wide test area at a height of 8 m, which is fully acceptable for the current standard for sub-main road.     

Formation of Additive Scale Representation of Information Using a Multielement Light Emitting Diode Display of a Measuring Instrument

An analysis is made of the principles of forming an additive scale representation of data using a display with a matrix electrical connection of light-emitting-diodes operating in a dynamic regime. A formalized procedure for synthesizing symbols is indicated and logical operators are obtained which describe the formation of the visual image in the information field of the display. An information model of additive form is proposed and analyzed for representing messages on the scale when scanning the matrix of elements along rows (the least significant digits).     

PLED发展现状分析

继CRT显示技术和LCD显示技术之后，PLED／OLED（统称为OEL）显示技术被业界定义为第三代显示技术，而PLED显示则是第三代显示技术中最适宜于大尺寸电视的技术。本文通过对PLED原理、技术、市场、发展状况和应用前景的分析，试图揭示PLED未来的广阔前景。     

Research on Testing System for Three-dimensional Distribution of Luminous Intensity of LED

In terms of asymmetrical three-dimensional distribution(ID) of luminous intensity(LI) of lightemitting-diode(LED),a testing system was conducted in this study.Design and principle of the testing system were introduced.31 photometers were placed on a concentric circle,and all of them were used to gather LI data of LED at the same time.The data acquisition card(DAC) was used to gather multichannel data and controlled motor.Experimental results indicated that the testing system had achieved the goal of testing threedimensional distribution of LI.And each parameter could meet the requirements of industrial production and measurement.     

基于LED光源的牙周炎光动力治疗的研究

LED具有价格低廉、结构简单、便携性强等优点,可以替代传统激光器作为光动力疗法的光源应用于医学领域。本文通过实验研究了LED光源用于体外牙周炎光动力疗法的可行性。研究以亚甲基蓝为光敏剂,对普雷沃细菌进行不同程度的光照处理,通过测量光照后细菌的存活率来检测LED装置的杀菌效率。实验结果表明,以LED替代激光器进行牙周炎光动力治疗,具有良好的杀菌率,在牙周炎治疗中具有可行性。