A large ballast resister is connected to the ground side electrode of our Xe fluorescent lamp with keeping the positive column in diffusive mode. In this configuration the potential of the ground side electrode becomes higher and floating, therefore the current flows out through the stray capacitor between glass wall of the lamp and ground becomes large and not negligible. In this paper we report the effect of ballast resistances ration between hight voltage side and ground side on the optical characteristics of the lamp. As the result, luminous efficacy increased and to maintain the diffuse state became easy by decreasing the ground side resistance. It is necessary to verify this effect by changing the driving frequency and the pulse width in the future.

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High voltage at the time of the start examined whether the emitter damage by the high energy shock with impressing it could become the proper means to accelerate the electrode deterioration of the fluorescent lamp till now. I conducted an investigation into the influence that aging appointed to JIS C 7617-2 gave deterioration this time and examined.

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A continuous improvement in the lumen output and efficacy of the cold cathode fluorescent lamps (CCFLs) is always expected. The lumen output and efficacy can be improved by controlling the electric field intensity in the discharge plasma by changing gas pressure. The authors investigated the influence of gas pressure on the cathode fall voltage (CFV) and the electric field intensity of the positive column. The measurement results show that the absolute value of the electric resistance per unit length of the positive column in Ne-Ar-Hg lamp increases with a rise in gas pressure, while the values of the Ne-Ar lamps do not change.

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It is well known that the electrode-less lamp ignites when E-discharge occurs and changes to H-discharge, but that mechanism about its transition has not been cleared. Authors investigated the way E-discharge changes to H-discharge in the electrode-less lamp operated at 150 kHz. Then they grasped that the transition time from E-discharge to H-discharge depends on the characteristics besides the operating circuit voltage applied before the lamp igniting.

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The fluorescent lamp systems driven by high frequency are very popular. Therefore it is very beneficial to be able to predict the lamp's life before the lamp dying. In order to judge the lamp life, a method for grasping the emission point, by calculating the filament resistance from emission point to the end of the filament, has been reported. The authors investigated the difference in the way the emission points moved for two lamp systems which are very popular. As the results, the emission point moving ways are influenced on the operating systems.

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The material of the carbon system including the diamond is a material as fee that has high potential. We are aiming at the achievement of the electrode for the liquid crystal backlight as a diamond thin film application. One clue from the relation between the discharging characteristic of the diamond electrode and the surface-roughness of the diamond to driving voltage decrease was obtained. Therefore, it is thought that the decrease of the driving voltage is more possible if a minute stylus of the high-aspect ratio can be formed on the surface of the diamond electrode. Secondary electron emission characteristics of the diamond electrode to which the surface was processed by reactive ion etching (RIE) of the parallel, monotonous type capacity uniting that used the MgO electrode were examined in the present study.

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When a fluorescent lamp at the end-of-life is ignited, a discharge spot is formed at the bottom of the lead wire. The mechanism of this dischrge spot formation is examined by the experiment. It is concluded that the spot is formed by the strong electric field formed between the lead wire and sputtered metal around the lead wire.

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The lifetime of a fluorescent lamp (FL) mainly depends on emitter loss from its electrode, i.e. the rate of emitter loss controls both of the lifetime and the efficiency of FL. We have clarified a part of mechanism of the emitter loss in FL. In this presentation, a relationship between the mechanism of emitter loss and the electrode temperature has been described. In the long-used FL, two hot spots were generated. Thermionic electrons and emitter atoms were emitted only from the one of these. In the other, the temperature was high and needless energy consumption for the discharge generation was large.

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The glass tube immediately after construction because of its prevention of the wound on the surface of the glass tube it was examined and it was examined to form the thin film of oxidation tin on the surface. (CH3)2SnCl2 was used for the material. SnO2 can be formed to the glass surface. Because hardness is larger than the glass, SnO2 is effective for the prevention of the wound formation. According to the Arrhenius rule, the rapidity of response has improved to the reaction by the temperature high as a result of investigating the temperature of the glass tube when processing it and the relation of the rapidity of response. It was confirmed to obtain desired a film thickness by controlling the temperature of the glass tube and the time when processing it as a result. Three point modulus of rupture of the glass tube where the thin film of SnO2 of 10?20nm degree had been confirmed to the surface was measured. Strength improved by about 40% in the coating goods compared with the result and the unprocessing goods, and the effectiveness of the coating processing was confirmed.

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It's often reported that light shifts the circadian rhythm of melatonin and that light helps humans keep the healthy circadian rhythm. It is supposed visible light of short wavelength is more effective to the circadian rhythm. In addition, visual pigment "melanopsin" (relates to melatonin secretion) was confirmed. To utilize the effect of short length light, we developed very high correlated color temperature FLs. The correlated color temperature is set about 12,000K which corresponds to fine skylight. We conducted field tests at our factory. We got results that under the new 12,000K FLs they showed 3-4% higher performance than before.

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FCL-type circular fluorescent lamps(FCLs) are still widely used for residential lighting in Japan, and expected to reduce the power consumption. We have therefore developed energy-saving FCLs. Ar/Kr mixed gas is utilized to decrease the impedance of the arc, and the distance from the end of the lamp tube to the electrode is increased to decrease the arc length. As a result, we have achieved to reduce the power consumption of new FCLs by approximately 5% of that of conventional FCLs in case of using with the electronic ballast having regular current output.

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"Development of an A-shaped self-ballasted fluorescent lamp using a helical tube. This lamp commercialized in 2008 has almost the same shape as that of an incandescent lamp, and also features power-saving and a long life. "

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(Development of ballast repeatable type CFL.)
In the situation in which the rise of consideration to the global warming prevention and environmental problems extend between consumers in all parts of the world, the compact self-ballasted fluorescent lamp is paid to attention. This time, we developed the ballast repeatable type CFL.Spread of the CFL with the energy conservation performance and the effect of the saving resource is expected as a source of light of the light bulb substitution.

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We developed the High Watt self-ballasted fluorescent lamp as same size as the current model. It is 9% energy saving and 67% longer life time for the current model, and it don't make the short life for much re-starting on-off cycle.

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Recently, the Visible Light Communication (VLC) techniques have attracted attention because of its high security and so on. In 2007, the standard concerning systems of VLC techniques using LED sources was defined by the Japan Electronics and Information Technology Industries Association (JEITA). This time, we report that, in the case of fluorescent lamp systems, we have completed VLC based on the standard by modulation of lamp operation frequency with a digital signal processor and by using photodiode having sensitivity peak around 436 nm in order to receive outputs of the lamp as accurately as possible.

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A significant improvement on discharge charcteristics such as cathode fall voltage or firing voltage was observed for trial manufacture cold cathode lamps that comprise 12CaO∙7Al2O3 crystals with F+ center (so-called C12A7 electride) as cathode material. The observed cathode fall voltage under Argon or Xenon discharge gas was smaller by 50-60 volts than those observed for Mo cathode lamp simultaneously prepared for the comparison. The result may be attributed to F+ center inherent to C12A7 electride, that gives small work function of 0.6-2.1 eV to the present material.

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The cold cathode fluorescent lamps(CCFL) is used for the LCD backlight. CCFL is characterized by long life, and various kind of tests has been done. In generally, accelerated test is normal to get long life reliability,but those phenomena have not been known so much. By the accelerated lamp current test, we investigated many influence on CCFL.

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Patterns of wall blackening on ceramic metal halide discharge lamps are investigated to quantitatively evaluate relative contributions of degradation mechanism.
Sample prepared with 2 minutes turn on/ 3minutes turn off operation procedure had shown a homogeneous blackening, while the tube of a continuously operate lamp exhibited blackening thicker toward the direction of gravity.
Contribution to the wall blackening due to wall reaction during continuous operation seems to predominate electrode sputtering at the discharge commencement judging from the light transmittance distribution of tested lamps.

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In order to realize mercury-free metal-halide lamp, it is important to know the spatial distribution of emission spectra in the lamp. However, since the arc shape is not symmetrical, it is imposible to know the spatial distribution using the Abel inversion. Therefore, the authors employed computed tomography technic to create the tomogram image from measured spectra. From the comparison between the tomogram images for In (450.87 nm) and Na (818.92 nm) emissions, it is found that the In emission shrinks into the arc center, whereas the Na emission diffuses. It is thought that the reson for this phenomenon is less diffusion for In because of larger atomic diameter compared to Na.

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Rupture characteristics of sealed parts in small type super high pressure lamps were investigated in this study. The rupture characteristics were important to design the quality lamps because of the operating pressure of the lamps were extremely high (more than 200atm). We employed water pressurizing system and FEM calculation to investigate the rupture characteristics. As the result, It was obtained that main factor of the rupture characteristics was disbonded area in the sealed parts and we estimate safety internal pressure of the lamps.

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This study investigated about decreasing of the stress generated in the seal of ceramic metal halide lamp. The seal of it is usually achieved by using the glass frit. The stress generated at the area is influenced by the difference in thermal expansion coefficient of the components (polycrystalline alumina, glass frit, niobium), which has is the possibility of causing the crack in the glass frit. This investigation revealed that the stress generated in the seal decreased by crystallizing the glass frit.

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The red color rendering index R9 of metal halide lamps is improved by change of arc tube material from quartz to alumina ceramic. However, further improvement of R9 is required in color critical applications such as fresh food retailing. We adopted the seamless arc tube (which capillaries and a body are integrally molded) for ceramic metal halide lamps to reduce thermal loss, and we researched the ratio and the amount of Calcium iodide and Lithium iodide to improve R9 while keeping a high luminous efficacy. We adopted two outer bulbs construction to adopt for open fixture, and reduced lamp size without sacrificing of safety and life performance.

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To achieve a lower break down voltage, ignition characteristic of mercury free ceramic metal halide lamp using with trigger wire is investigated. Parameter of the trigger wire structure is number of turns around capillary, turn around bulb and connecting to electrode. Without the trigger wire, breakdown voltage is above 6kV. But using with the trigger wire which connecting to the odd electrode and brought into contact with the bulb, breakdown voltage is 3.4kV.Creep discharges which follow the trigger wire tend to accompany lower break down voltage. It is inferred that breakdown voltage is correlated with discharge pass.

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We investigated a light generating material that was able to generate the lamp voltage in place of the ZnI₂ and the high-pressure Xe gas. We selected TmI₃ from ionized energy, the vapor pressure, and the radiation power. Because TmI₃ generate a high lamp voltage as a result of examining it, we have found that high lamp efficiency is obtained while improving the breakdown voltage. For example, the maximum lamp voltage of 62V and the maximum lamp efficiency of 95lm/W were obtained in the high Xe pressure lamp of 30watts.

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Study of high power ballast for step-dimable induction lamp.

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a basic illuminator with a fluorescent lamp is adopted from viewpoints of the improvement and the economy etc. of the power saving and the visual environment in the tunnel lighting whose hid source of light is a main current so far. however, the low-pressure sodium lamp is often used from there is a problem in low-temperature characteristics of a fluorescent lamp in the cold district. then, because the tunnel illuminator with high frequency lighting fluorescence lamp (hf32w) that can be adopted in the cold district was developed, it reports.

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The point source of light such as fluorescent lamps were used as various illuminators. However, surface light source such as the organic EL lightings were developed, recently. These surface light source may have a different illumination distributions compared with previous point source of light. Therefore, illumination distributions of virtual office have been calculated using Monte Carlo simulation method. From our calculation, it in clear that the mean illumination distributions of the EL lightings lower than that of the fluorescent lamp of the same brightness, on the other hand, uniformity ratio of illuminance of the EL lighting goes up.

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Calculation of illuminance and sky factor by the luminance distribution measurement tool using a digital camera

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While becoming interested in higher quality lighting, people have revalued candle lighting. In order to develop an LED lighting system simulating comfortable fluctuation of Japanese candles, this study measured and analyzed modulation of Japanese candles. The result of the analysis suggested that: (1) the power of the modulation of the candle flame decreases as an inverse function of frequency, and (2) the frequency of Japanese candles was different from the frequency of Western candles especially around a frequency of 10Hz. Additionally, in this frequency range, Japanese candles have a distinctive modulation pattern in which candle flame extends and shrinks like a spring.

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We examined the prediction procedure for finding position of light source when the combination of room reflectances is varied.
As a result, it is clear that the area mounted the light source and the position of the light source decided by using Monte Carlo Method and binary process.

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Kidnappings and snatches threaten people's lives now. The majority of the victims are women, and many of the crime situations are residential areas at nighttime. This study was aimed at the creation of the lighting environment at nighttime in the residential area where it can walk with the person relieved enough. In this study, the psychological experiment was conducted by using 3D stereoscopic vision. As a result, it was effective to use a garden light together as a supporting source of light and got the prospect that could build reasonable illumination environment to be able to walk in peace.

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A Light-shelf system is being watched with the point of view of energy-saving. This paper is application research on the nighttime of the Light-shelf system.

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n the research, we measure how human eyes sees object color , especially under dark conditions. From the results, it is known that when the reduction of the surrounding illuminance of the signboard at a certain point, human eyes shift from seeing the signboard as object color to light source color.This shift point start when horizontal plane illuminance reduced to 1000 luminance flux ( lx ) and when the illuminance reached 100 lx, seeing the signboard color as a light source exceed seeing it as an object color.From the results it is also known that human eyes sees object color as light source color when the luminance is under 200cd/_m2_.

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We investigated the areas where the blue crime prevention light was introduced after several months and two years it was introduced. As a result of the hearing survey, it was thought about a blue light as a symbol to urge the crime prevention consideration. As a result of the questionnaire survey, because of the anticrime activity in the area positively done the evaluation has improved. But because of novelty faded and a decline of luminous flux of a lamp, the evaluation has worsened. The crime occurrence number shows the tendency to decrease overall.

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Influence that pyhsical factor gives to a favorable impression of a night view.

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The goal of this study is to clarify the lighting requirements for makeup.We conducted evaluation experiments on the interior lighting conditions with dimmer desk lamp. As a result of the experiments, we cleared up the lighting level for each makeup class and suggested the using of the dimmer lamp provided the suitable lighting level for makeup.

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This study finally aims to determine the appropriate lighting conditions for cooking in the kitchen. In the kitchen, a family prepares and makes their dishes; washing, cutting, peeling and cooking, creating the possible danger of cuts and burns. In this study, we conducted the experiment on the subjective evaluation for cooking under a variety of conditions of light source, illuminance, light color, and light direction. Subjects evaluated "Brightness", "Visibility", "Task Performance" and "Satisfaction". As a result, it was determined that the subjects' evaluation differed according to the light direction under the same conditions of illuminance on the work table.

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Recently, there are Machiya-cafes which are renovated from Japanese traditional houses called "Machiya" in Kyoto. In this study, we focused on the effect of leaking light through the lattice from Machiya-cafe at night on the evaluation of cafe. And we conducted the experiment on the subjective evaluation. The subjects evaluated the 5 evaluation factors, "Clarity", "Enterability", "Restfulness", "Regionality", and "General evaluation" with. As a result, it was shown that the components of cafe facade, "Lattice", "Plants" and "A split shop curtain" and the leaking light through the lattice from Machiya-cafe at night influenced the evaluation of cafe.

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The aim of this study was to investigate the characteristics of luminance distribution calling forth conspicuity in the human mind. The study also established a system that transforms luminance distribution into an image of human-perceptual simulation called a 'Conspicuousness image'. A subjective assessment was performed. The experimental variables were target size and luminance ratio (target luminance/background luminance). The subjects simply observed the targets (round shapes of various sizes and with varied luminance), and ranked the conspicuousness of each target. The result is well explained by Nakamura's analysis approach, which is called the contrast profiling method.

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Consideration of Lighting plan using the Lighting Environment Evaluation System

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Under construction.

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Development of Visual Environments Using the Metric of Space Brightness For measurement and design reflectivity of space

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The appearance and diversification of methods of lighting a new light source, and feel the horizontal illuminance of the conventional design index " the Metric of Space Brightness" the situation does not match the increase. In these reports are many ways to estimate the brightness of the sense of space. Calculated from the brightness distribution of the field to the one proposed by Iwai Feu some value, is calculated to require a simulation of the brightness distribution of the field, takes a long time, is not simple. So in this study, case studies and T Building in Tokyo, for each condition was calculated from the distribution of brightness values based on simulated Feu, Feu simple report so that the methods to calculate the value.

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It is shown that the appearance of a building and interior lighting through the window from outside influence occupant's rating related to the brightness. The relationship between combinations of the various lighting design indexes and the brightness when observe cafes from outside are found out by the subjective experiment with scale model. The model which imitated a cafe has a window. Subjects observe the scene through it, and rate brightness of the interior, brightness of the exterior, the balance of them, feeling cozy and impressions. The results show that brightness of the interior is low with higher luminance of exterior when luminance of interior is same.

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Relation of initial lighting environment, task illuminance and allowance rate of task-ambient ratio T/A are shown in this report based on the assessment experiment. T is an illuminance at the center of working area, and A is the center illuminance only by the ambient lighting. Subjects are 30 persons aged 20 from 41 years old. The higher the working area illuminance is, the larger the accepted T/A is. T/A of the non-uniform initial lighting environment is larger than that of the uniform case.

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Studies aimed to establish the evaluation method of blur level of a target seen through figured glass has carried out. We pay attention to a ray pass through figured glass is refracted according 'Snell's law' and lead equations tracing ray. In this paper, some simulated blur images seen through figured glass with simple shape are shown.

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Traffic accident of older drivers keeps increasing every year. In this research, the decrease of visual characteristics of older drivers was analyzed. The computer graphics that simulate in consideration of the aging change in the visual characteristics was developed. The influence that the glare veiling of the headlight exerted on a peripheral visibility was examined.

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The influence of the daylighting and the artificial lighting on interior brightness is examined

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In cloudy judgment, we compared existing system to new system (pictorial images of luminance distribution system). As a result, new system was accurate compared existing system. In addition, new system may enable continuous prediction of skylight condition, not only an instant judgment. In blind salt angle setting based on discomfort glare evaluation method, we developed simulation flow of blind slat angle setting based on discomfort glare evaluation method.

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There are two kinds of Noh stages, one is an outdoor Noh stage lit by natural light, the other is a Noh stage in a theater lit by artificial lighting. As an exsample, photometry surveys were carried out in each Noh stage and the distributions of illuminance and luminance were compared. Several differences on the lighting effect between both Noh stages were found out.

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