Flicker responses of different lamp types

Nowadays, more and more lamp types are being used. Since different lamp types have different working principles, they also have different flicker responses. This paper shows the measurement results of different flicker responses for various types of lamps. These results prove that the UIE/IEC flickermeter, which has been used widely around the world for many years, cannot be used to advise on the flicker level of all lamp types. This is because of the fact that this flickermeter is based on a 230 V, 60 W or 120 V, 60 W incandescent lamp and can be used as reference only for this type of lamp or as reference to the standard. The UIE/IEC (International Union for Electricity Applications/International Electrotechnical Committee) flickermeter and the existing standards are therefore insufficient for other lamp types. This paper describes a proposal to improve the UIE/IEC flickermeter.     

Electric lamps, past and present

The article traces the story of the electric lamp, which began when, in 1810, Davy demonstrated the now legendary `bright carbon arc' that led, in 1850, to the production of practical arc lamps. Because of the `powerful' intensity of the arc lamp, there was a demand for `the subdivision of light' and this culminated, in 1879, in the invention of the incandescent filament lamp. Gaseous and vapour discharge lamp research began around 1850 and practical lamps were available in the early 1900s. There were carbon dioxide, nitrogen and neon filled tubes giving `daylight', `sunlight' and red light emissions, respectively. Also, and still available, there were high-voltage, mercury vapour, cold-cathode fluorescent tubes. Following research in the early 1930s mains voltage, high- and low-pressure mercury and sodium vapour lamps have been under constant development and they are widely used today. Fluorescent lamps, introduced in 1938, are regularly being improved in design and among the latest are compact energy saving types that are ideally suited, as direct replacements, for GLS lamps. The recent announcement of the QL induction lighting system is the latest milestone in `electric light' invention     

基于正多面体演变的正星体状模块化灯具设计研究

目的在现有的立体几何模块化灯具基础上,研究灯具模块之间组合变化的设计新方法。方法通过对立体几何灯具的原型柏拉图立体、阿基米德立体、卡塔兰立体等的观察和研究,进而在立体几何模块化灯具的基础上,寻找立体几何模块化灯具设计的共同点,总结立体几何模块化灯具设计的规律,根据对模块化灯具连接点规律的探索,使灯具架构不变,改变相邻造型因子达到创造各种立体几何灯具衍生造型的目的,以此指导模块化灯具设计研究。结论在立体几何模块化灯具的基础原理上,将相邻造型因子组合变化,在其架构不变的基础上改变模块化灯具的外观,丰富了模块化灯具设计的种类,提出了模块化灯具设计的新方法。     

汞离子微波频标光学设计

汞离子微波频标利用汞灯进行抽运,可实现小型化,同时具备体积小、指标高的优势,未来可在卫星导航、深空探测和守时中得到广泛应用。为了提高抽运效率及降低噪底,需要进行汞灯光学设计,使抽运光通过四极阱中心与囚禁离子充分作用的同时减少与真空腔及四极杆的反射。首先提出遮挡光源法和非等比例放大法两种光学设计方法。然后介绍了两种设计方法的具体设计过程和设计结果,并比较了两种光学设计方法汞灯的能量利用率。最后利用非等比例放大法进行光路优化设计,并完成了物理系统信号探测实验。实验结果表明：采用该光学设计方案,汞离子光微波双共振跃迁信号幅度提高了20%以上。     

Development of a new transfer standard for high UV irradiances

Source-based radiometry requires reliable transfer standards which are easy to handle. For low irradiances in the UV spectral range, 30 W deuterium lamps are commonly used. However, for the growing field of high UV irradiance applications, new high power standards are required. Here we report on a Xe-Hg lamp system which has been characterised and improved to match the high requirements of a working standard. For this purpose, several parameters of the system such as lamp stability, re-ignition reproducibility, irradiance uniformity and usability have been investigated. Components for the customised light guide-based output optics have been selected with the help of extensive characterisations. The resulting lamp system can be used for a high-grade instrument calibration at high UV irradiance levels.     

立式双开门汽车灯具高真空镀膜设备的研制

阐述了一种立式双开门汽车灯具高真空镀膜机的系统原理及结构特点,重点介绍了离子轰击、清洗系统在该设备中的应用,并对最终产品进行了测试和分析。测试表明:灯具反射镜在波长390～770 nm段的反射率高达92%,达到并超过国家标准80%的要求;灯具反射镜劣化试验显示:保护膜对镀铝膜的保护效果良好,样品在30min内无腐蚀现象;胶带附着力及百格试验测试没有观察到膜层脱落现象。     

Analysis and fabrication of minifeature lamp lens by excimer laser micromachining

A variety of shapes of lamp lenses at the feature millimeter scale have been extensively used in lamp design. To further improve the light efficiency and to reduce the overall dimension of lamps, the lamp lens at the micrometer scale is fabricated by excimer laser cross scanning on a polycarbonate sheet. To verify the proposed method, the influence of an optical system with various shapes and sizes of lamp lenses on the light efficiency is explored in advance by ASAP optical software. The lens with a miniature feature can produce a smaller divergence angle than that with a large-size lens feature. The experiment is carried out at varying laser operating parameters, mask shape, and dimensions. The simulation shows that the desired lamp lens profile can be effectively produced by excimer laser micromachining.     

Comparison of direct and alternating current vacuum ultraviolet lamps in atmospheric pressure photoionization

A direct current induced vacuum ultraviolet (dc-VUV) krypton discharge lamp and an alternating current, radio frequency (rf) induced VUV lamp that are essentially similar to lamps in commercial atmospheric pressure photoionization (APPI) ion sources were compared. The emission distributions along the diameter of the lamp exit window were measured, and they showed that the beam of the rf lamp is much wider than that of the dc lamp. Thus, the rf lamp has larger efficient ionization area, and it also emits more photons than the dc lamp. The ionization efficiencies of the lamps were compared using identical spray geometries with both lamps in microchip APPI mass spectrometry (μAPPI-MS) and desorption atmospheric pressure photoionization-mass spectrometry (DAPPI-MS). A comprehensive view on the ionization was gained by studying six different μAPPI solvent compositions, five DAPPI spray solvents, and completely solvent-free DAPPI. The observed reactant ions for each solvent composition were very similar with both lamps except for toluene, which showed a higher amount of solvent originating oxidation products with the rf lamp than with the dc lamp in μAPPI. Moreover, the same analyte ions were detected with both lamps, and thus, the ionization mechanisms with both lamps are similar. The rf lamp showed a higher ionization efficiency than the dc lamp in all experiments. The difference between the lamp ionization efficiencies was greatest when high ionization energy (IE) solvent compositions (IEs above 10 eV), i.e., hexane, methanol, and methanol/water, (1:1 v:v) were used. The higher ionization efficiency of the rf lamp is likely due to the larger area of high intensity light emission, and the resulting larger efficient ionization area and higher amount of photons emitted. These result in higher solvent reactant ion production, which in turn enables more efficient analyte ion production.     

一种兼顾照明与通信的环形光源布局模型

传统基于阵列的光源布局方式在室内难免存在光照度及系统误码率不均匀现象,为提高系统照度均匀性及通信可靠性,需合理对光源进行优化布局。本文以4 m×4 m×3 m的房间为模型,设计了单LED阵列+灯带的环形光源布局模型。模型中间采用6×6 LED阵列,阵列内部灯珠之间的距离为0.3 m;四周采用环形灯带形式,灯珠个数为316个,灯珠之间的距离为0.05 m。仿真结果表明,该模式下系统光照度均值为437.08 lx,光照度均匀性为93.9%,同时,系统误码率均值为2.8716×10-7。因此,本文所设计的环形光源布局模型兼顾了室内光照度分布的均匀性和通信的可靠性,可同时满足室内照明和通信,为室内可见光通信光源布局提供了一种优化方法。     

The Design of Stabilized Power Supplies for Incandescent Light Sources

Incandescent lamps are used as wide-band sources of light in many optical/electronic instruments, and the present paper describes some approaches to the design of stabilized power units for these lamps. Both dc and pulse-width modulated ac supplies are described, and a series of design equations for the latter are established. Where the lamp voltage is to be monitored rather than the light output itself, some unique advantages are claimed for the use of a lamp-photoresistor assembly (or calistor) within the feedback loop. Several example designs are given, from which a variety of power supplies may be developed.     

Temperature estimation of high-power light emitting diode street lamp by a multi-chip analytical solution

Light emitting diodes (LEDs) are now widely used in many fields including traffic lights, vehicle backlights and liquid crystal display (LCD) displays because of their long life, good illumination efficiency and low energy consumption. At present, LEDs are increasingly replacing the traditional lighting and are being used in general illumination such as the street lamp. For the high-power LED street lamps, good light extraction is the most important thing, but low junction temperature of the LED modules is also critical for achieving a long lifetime and a high optical efficiency. Actually, there have been many reports about early failures of street lamps, called dead lamps that have been regarded as a barrier in the public and administration acceptance of LED street lamps. Therefore temperature estimation is always a crucial issue for LED product development. A multi-chip spreading thermal resistance model was applied to estimate the temperature distribution of LED street lamp. The experiment was first done to obtain temperatures of several locations in a prototype LED street lamp. Then the multi-chip spreading resistance model was established to calculate the full temperature distribution. Comparison between the model calculation and experimental measurement showed a good agreement, which demonstrates that the present model can be used in engineering design to estimate the temperature distribution of high-power LED street lamps.     

LED照明的杂散光分析与散热研究

针对LED照明杂散光的形成原因和处理方法,以及LED照明系统散热问题的产生和结温对灯具寿命和发光率的影响,完善LED照明灯具的设计,利用照明灯具的特点,以目前LED照明灯具采用的散热方式和杂散光的处理形式为基准,采用对比测试的方法对灯具样品进行检验测试。通过对检测结果的分析,解决了LED照明的散热设计中涉及到的关键问题。     

Comments on "Accuracy of Raman lidar water vapor calibration and its applicability to long-term measurements"

In a recent publication, Leblanc and McDermid [Appl. Opt., 47, 5592 (2008)]APOPAI0003-693510.1364/AO.47.005592 proposed a hybrid calibration technique for Raman water vapor lidar involving a tungsten lamp and radiosondes. Measurements made with the lidar telescope viewing the calibration lamp were used to stabilize the lidar calibration determined by comparison with radiosonde. The technique provided a significantly more stable calibration constant than radiosondes used alone. The technique involves the use of a calibration lamp in a fixed position in front of the lidar receiver aperture. We examine this configuration and find that such a configuration likely does not properly sample the full lidar system optical efficiency. While the technique is a useful addition to the use of radiosondes alone for lidar calibration, it is important to understand the scenarios under which it will not provide an accurate quantification of system optical efficiency changes. We offer examples of these scenarios. Scanning of the full telescope aperture with the calibration lamp can circumvent most of these limitations. Based on the work done to date, it seems likely that the use of multiple calibration lamps in different fixed positions in front of the telescope may provide sufficient redundancy for long-term calibration needs. Further full-aperture scanning experiments, performed over an extended period of time, are needed to determine a "best practice" for the use of multiple calibration lamps in the hybrid technique.     

Applying visual attention theory to transportation safety research and design: Evaluation of alternative automobile rear lighting systems

This field experiment takes a novel approach in applying methodologies and theories of visual search to the subject of conspicuity in automobile rear lighting. Traditional rear lighting research has not used the visual search paradigm in experimental design. It is our claim that the visual search design uniquely uncovers visual attention processes operating when drivers search the visual field that current designs fail to capture. This experiment is a validation and extension of previous simulator research on this same topic and demonstrates that detection of red automobile brake lamps will be improved if tail lamps are another color (in this test, amber) rather than the currently mandated red. Results indicate that when drivers miss brake lamp onset in low ambient light, RT and error are reduced in detecting the presence and absence of red brake lamps with multiple lead vehicles when tail lamps are not red compared to current rear lighting which mandates red tail lamps. This performance improvement is attributed to efficient visual processing that automatically segregates tail (amber) and brake (red) lamp colors into distractors and targets respectively.     

Developments in Light Sources for Filming and Projection

The paper is a review of recent developments in light sources for filming and projection in both the amateur and the professional fields. Three recent major technical advances are described, namely: Halogen Lamps, Sealed Beam Lamps and Dichroic coating, as applied to lamps, are dealt with in some detail. The most important lamp designs for each particular application are also reviewed     

1.2 Measuring technique for partial hydrogen pressures in nitrogen-neon atmospheres

Gaseous impurities inside the discharge tube of a high pressure metal iodide lamp can have a large influence on the electrical and radiation properties of the lamp. Since the main gaseous impurity is hydrogen this gas must be eliminated from the discharge tube. One way of eliminating this gas is to use a hydrogen gettering material inside the outer bulb of the lamp since, under operational conditions hydrogen can diffuse through the quartz wall of the discharge tube into the outerr bulb.Because most types of high pressure metal iodide lamps have a mixture of a noble gas and nitrogen inside the outer bulb the gettering material must react only with the hydrogen and not with the nitrogen. For this reason the qetter has to be selective. In order to invistigate the selective gettering action of different chemical compounds a simple measuring technique was used to measure continuosly the hydrogen partial pressure inside the nitrogen-noble gas atmosphere.Most investigators use a mass-spectrometer or a gas chromatograph to register the change of the partial hydrogen pressure during the lifetime of the lamp. A much better technique is the use of a nickel diffusion leak combined with a manometer. A higher accuracy can be reached with this methods and it is possible to add or pump away thhe hydrogen without changig the nitrogen or noble gas atmosphere.The selective gettering action of a ZrAl alloys has been examined by this measuring technique and the results of this investigation are given.     

Analyzing experiments with degradation data for improving reliability and for achieving robust reliability

Statistically designed experiments provide a proactive means for improving reliability; moreover, they can be used to design products that are robust to noise factors which are hard or impossible to control. Traditionally, failure‐time data have been collected; for high‐reliability products, it is unlikely that failures will occur in a reasonable testing period, so the experiment will be uninformative. An alternative, however, is to collect degradation data. Take, for example, fluorescent lamps whose light intensity decreases over time. Observation of light‐intensity degradation paths, given that they are smooth, provides information about the reliability of the lamp, and does not require the lamps to fail. This paper considers experiments with such data for ‘reliability improvement’, as well as for ‘robust reliability achievement’ using Taguchi's robust design paradigm. A two‐stage maximum‐likelihood analysis based on a nonlinear random‐effects model is proposed and illustrated with data from two experiments. One experiment considers the reliability improvement of fluorescent lamps. The other experiment focuses on robust reliability improvement of light‐emitting diodes. Copyright © 2001 John Wiley & Sons, Ltd.     

Compact fluorescent lamp phosphors in accidental radiation monitoring

The application of lamp phosphors for accidental dosimetry is a new concept. Since the materials used in fluorescent lamps are good photo luminescent materials, if one can either use the inherent defects present in the phosphor or add suitable modifiers to induce thermoluminescence (TL) in these phosphors, then the device (fluorescent lamp) can be used as an accidental dosemeter. In continuation of our search for a suitable phosphor material, which can serve both as an efficient lamp phosphor and as a good radiation monitoring device, detailed examination has been carried out on cerium and terbium-doped lanthanum phosphate material. A (90)Sr beta source with 50 mCi strength (1.85 GBq) was used as the irradiation source for TL studies. The TL response as a function of dose received was examined for all phosphors used and it was observed that the intensity of the TL peak vs. dose received was a linear function in the dose range 0.1-200 Gy in each case. Incidentally LaPO(4): Ce,Tb is a component of the compact fluorescent lamp marketed recently as an energy bright light source. Besides having very good luminescence efficiency, good dosimetric properties of these phosphors render them useful for their use in accidental dosimetry also.     

High-definition imaging system based on spatial light modulators with light-scattering mode

We have developed a prototype high-definition imaging system using polymer-dispersed liquid-crystal (PDLC) light valves, which can modulate unpolarized light with high spatial resolution and exhibit a high optical efficiency, based on the light-scattering effect. We fabricated high-definition light valves with a fine polymer-matrix structure in a PDLC film by controlling the curing conditions used during the photopolymerization-induced phase separation and formation process. This device has excellent characteristics, such as a high resolution, with 50 lp/mm for a limiting resolution and greater than 20 lp/mm at the 50% modulation transfer function point, and a reflectivity of greater than 60%. An optically addressable full-color projection display was designed, consisting of three PDLC light valves, a schlieren optical system based on shift-decentralization optics with a xenon lamp illumination and input-image sources with 1.5 million pixels, including electrical image compensation of the gamma characteristics. We succeeded in displaying pictures on a 110-inch screen with a resolution of 810 TV lines and a luminous flux of 1900-2100 American National Standards Institute lumens.     

竹编在当代灯具设计中的新生

目的 为传统竹编在当代灯具设计中的活化传承探索有效的途径和思维方法。方法 分析传统竹编日渐走向没落的根本原因,为其新生之路提供借鉴。在发掘传统竹编的材性、材质以及工艺美学等潜能的基础上,结合时代背景从工艺革新和产品创新2个角度着手探寻传统竹编的脱困途径,分析竹编材质特性与灯具产品功能特征的协调性。从设计方法与生产工艺、传统基因与时尚潮流、多元材质结合3个角度,探索竹编在当代灯具设计中的设计思路。结论 传统竹编的新生必须在产品类型、生产工艺、设计思路等方面与时代发展的脉络相结合。灯具是竹编实现新生的理想载体,竹编的材质优势、工艺美学以及文化渊源是当代竹编灯具设计的重要突破口。