The influence of electrode material on plasma characteristics had been investigated for mercury-free fluorescent lamp. In this experiment, the breakdown voltage and plasma density are examined at electrode materials such as aluminum, magnesium oxide and SrTiO3 using argon and neon gases. It results that the breakdown voltage decreased with increasing gas pressure from 0.1 to 1.25Pa, and the discharge voltage for neon is higher than one for argon at both electrodes. It was found that the plasma density estimated from the ion saturation current increased with increasing gas pressure at both gases.

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The roughness of diamond surfaces were formed using O2 gas in a reactive ion etching (RIE) system. The electrode materials were used stainless steel (SUS) and MgO sintered ceramic. The samples to be etched are positioned on the power electrode. After diamond etching, the roughness surfaces of diamond were observed with atomic force microscope (AFM). The breakdown voltages of diamond electrodes were measured under various Ne pressure with a V-Q Lissajous method. The nanoneedle array on the surface of the diamond was fabricated at MgO electrode.

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Wall blackening of a fluorescent lamp was observed to see the effect due to a short duration turn-on/turn-off operation. The lamp had shown a rapid wall blackening at the lamp end, when it was operated with a turn-on/turn-off procedure from the as received condition. Any continuous operation at the rated power with the time longer than 6 hours prior to the turn-on/turn-off operation had indicated moderate progress of wall blackening. The electrode showing deeper blackening tended to produce smaller electron emission corresponding to depletion of emitter from the electrode.

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We investigated discharge characteristics in cold cathode fluorescent lamps of 4mm inner diameter used for backlighting of liquid crystal display. MgO film has a high secondary electron emission. The material of electrode on one side was a Ni, and on another side that was a MgO thin film on Ni. The filling gas in the lamp was Ne. The cathode voltages of lamp with the electrodes made with different materials were simultaneously measured with high voltage probe connected to digital oscilloscope when the lamp was operated by sine-wave on the same condition.

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The authors have been developing mercury-free fluorescent lamps and reported a luminance and efficacy improvement method by using an auxiliary external electrode (AEE). In this study, instead of simply grounding the AEE, another HV pulse was applied to the AEE, which was synchronized to the driving HV pulse and further luminance and efficacy improvement was achieved.

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The authors have been developing mercury-free fluorescent lamp, mainly for general lighting purpose (inside diameter of 26 mm), and enhancing its luminance and efficacy using auxiliary external electrode (AEE). In this study, for thinner lamp (inside diameter of 8.7 mm) with the AEE, the shape and the size of the inside electrodes were optimized. It is found that thinner and longer cathode (high voltage side) and thicker and shorter anode (ground side) are preferred when sleeve shape electrodes.

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For Fluorescent lamp electrode, lead-glass has been used for the reason of good processability, though the content of the poisonous substance is prohibited in the RoHS Directive. Lead-free glass that has good processability is strongly required to take the place of lead glass for fluorescent lamp.In addition, the glass strength decrease due to wound on the surface was a problem though the lead free glass had been adopted in the CCFL lamp. We improved processability by decreasing specific heat of the glass by controlling of Alkali earth element content. And we improved the strength of glass by surface-active agent coating.

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In order to discuss the effects of ambient gas and total pressure on the emitter material loss from the electrode of a low-pressure fluorescent lamp (FL), a LIF technique and a black-body radiation method have been applied to the Ba atom density measurement and the electrode temperature measurement, respectively. It is shown that the decrease of the Ba atom loss with the pressure increase is mainly due to the decrease of the hot spot temperature. It is also suggested that control of the hot spot temperature is most important for an effective and long-lived FL.

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It is possible to enhance the injection current to xenon cold cathode mercury-free fluorescent lamps with suppression of positive column contraction by using an auxiliary external electrode. Investigation of electron density distribution is required in order to analyze mechanisms of positive column contraction after local ionization concentration. The authors employed CO2 laser interferometry to measure electron density distribution because it has high special resolution and does not disturb the plasma. The electron density of 2.5×10¹³ cm^-3 was obtained at the center of positive column for the lamp with 50 Torr xenon, 50 mm of inter-electrodes, 14 mm of lamp inside diameter and 25 mA of injection current. As a future task, variations of electron density distribution by the auxiliary external electrode will be examined.

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Deuterium lamp with multiple pinhole which constrict positive column was manufactured experimentally. As a result, wide UV irradiating area is obtained from joinning with irradiation from each pinhole.

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Development of the mini krypton bulb shaped self ballasted fluorescent lamp. This lamp commercialized in 2010, has been downsized up to that of a mini krypton bulb PS45 type and features power-saving and a long life time.

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In a ceiling light for houses, I developed the lighting equipment which I added a-like light function to automatically which let I was automatic, and the fluorescent light output change to keep the brightness that I used a brightness sensor and set for a change of neighboring brightness. The interior of the general house is various, and wide dynamic range is necessary for brightness detection by color of the carpet or having table or not so that reflectance is different greatly. In other words adaptability for various room environment becomes the problem. Therefore I adopted a load resistance reshuffling circuit and planned precision improvement of the brightness detection for wide reflectance.

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The fluorescent lamp had been adopted for the pulse superposition method and frequency modulation method in the electric ballast to dim deeply.These ways have problem that are the complication of the circuit and noise.We design the electric ballast which can fade in.

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An electrodeless discharged lamp is expected to be a light source for next generation, because it has some industrial advantages such as long lifetime, high lamp efficiency, and relatively high color rendering property. As the strength of light emission is affected by plasma in the lamp, it is effective to figure out electron density in plasma for improvement of the lamp efficiency. In this report, we focused on the transmitted power from exciting coil to the plasma and investigated the designs of power coupler in the lamp.

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Mercury-free metal halide lamps for automotive purpose have been developing in the market. When mercury is not used, the electric and emission characteristics of the lamp strongly depend on the xenon filling pressure. Therefore a simple and non-destructive gas pressure estimation technique used in production lines is required to obtain stable performance of the lamps as commercial products. The authors have developed an estimation method by which the gas pressure is estimated from the current peak value at the initial stage of ignition under pulsed operation. It is shown that the accuracy of the order of +-(0.1--0.3) atm is obtained using an empirical formula.

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It is thought that a more accurate life prediction is possible if there is something that becomes the index of deterioration in addition though the HID lamp is known the luminous tube is made black along with the driving time and the illuminance decreases. The electrical discharge period was discovered to tend to extend being deteriorated the lamp because the glow discharge period when the electric power was turned on was measured in the present study. It doesn't depend on the driving history of the lamp and the electrical discharge period extends according to a decrease in the illuminance, and then, this relation can be used as an index of the lamp deterioration and it is thought that whether it is possible to become the index of new deterioration this correlation is investigated.

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Thoriated-tungsten (ThO2-W) is popularly used for the electrodes of a super-high pressure mercury lamp, or for arc-welding, because of its excellent performance as to the electron emission. Because it is radioactive, however, a new material which can replace it would be desirable. We have attempted to find a material to replace ThO2-W as the electrode. We have found that neodymium oxide or samarium oxide made under certain conditions produces encouraging results.

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We have examined influence of light emission luminance and electron density with the generation of the radio-frequency discharge plasma by changing the tube diameter of 30mm and 20mm. Phosphor (BaMgA110017:EU) was applied for Xe excitation with Ne-Xe mixture gases. It was found that at the flow rate with 50sccm and 100sccm of Ne and 0.1-4sccm of Xe, light emission luminance for 30mm tube diameter was higher than one for 20mm diameter. It was also obtained that the measured electron density for the 20mm tube diameter was higher than one for 30mm diameter. This apparent contradiction would be caused by the re-combination near the tube wall.

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Spherical-shaped electrodeless lamps are known as one of high-efficacy, long-life light sources. In the inner space of these lamps, mercury plasma, which contributes to excite phosphor materials with its UV radiation, is generated. Therefore studying the behavior of mercury plasma is important for increasing luminous flux of the lamp. Based on these understandings, we have measured the light emission spectrum from mercury plasma in the lamp, and then calculated the spatial distribution of light emission with respect to each wavelength. These results can be applied to further investigation of mercury plasma behavior to find the key of increasing luminous flux.

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Traditionally, administrators have been spending labor and time to manage and recover the magnetic cards or coins by traditional lighting control systems which use the magnetic cards or coins. Also, users have to borrow the magnetic cards or coins from the contact. The lighting system used two dimensional barcode which has been used in various fields in recent years is developed for laborsaving in rental service. Administrators need not manage and recover the barcode by the system used barcode. Also, users need not borrow the barcode from the contact. The developed lighting control system is effective means for laborsaving in rental service.

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The concern of the energy saving is inc reasing in China.We developed the lighting controller with lighting sensor for the Chinese market.That was designed based on the existing controller in Japan. We changed the dimming signal from the control by pulse width modulation (PWM) which is mainly used in Japan to the control by d.c.voltage widely used in Chinese.This system will contribute to the environmental protection in a Chinese market.

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In the lighting fixtures in a metal processing factory, where oil mist adhesion to the fixtures from the water-based cutting fluid has happened, the anti-contamination layer made from the developed water- and oil-repelling coating on the reflectors suppressed oil-mist adhesion and enabled easy wiping. This anti-contamination functional layer is a copolymer made from an acrylic unit bound with polysiloxane, which has a high value of both static contact angle and retracting contact angle, and a fluorine unit, which has low surface energy and high orientation property on the surface. This copolymer layer contains oil-mist repelling composition densely localized on the reflector surface, and forms a fluorine-polysiloxane coating bridged densely in three dimensions. The developed technology enables long-term maintenance of the initial high fixture efficiency and improves the work environment in the factory as well as achieves energy conservation.

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

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This study aims to show the preferable lighting conditions for the appearance of dishes and good communications with family in the dining room. We conducted the experiment on the subjective evaluation under 14 lighting conditions in total, which combined light source, light colour and illuminance. 20 subjects evaluated "Brightness","Visibility", and "Preference of the appearance" for each object; dishes on the dining table and face of subjects sitting at dining table. And they evaluated "Impression of the dining table" with the Semantic Differential method. The results showed that evaluations dpend on illuminance, colour temperature, and spectral distribution of light source.

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In this study, we carried out a subjective experiment of the visibility of food ingredients, cooked meat and recipe book, using light of different sources, illuminance and colours. Before this experiment, we produced 3 indexes; colour charts for the food ingredients, colour charts for cooked meat and recipe book. We created 48 different lighting conditions with a combination of illuminance and light colour, using fluorescent lamps and LEDs. Subjects evaluated the visibility for the food ingredients, the visibility for cooked meat and the visibility for recipe book with categorical scales and ME method. According to the results, it was shown that the appropriate conditions of illuminance and colour temperature in making meals.

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Questionnaire survey in the elementary school classrooms was conducted to identify the use of daylight and that of the ceiling luminaires. It was identified that the teachers controlled both the ceiling luminaires and sunshade devices in more than 90% of the measured classrooms. Also it was identified that the

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Providing a adequate brightness and keeping enough outside view as well as preventing discomfort glare are required performance for venetian blinds. The purpose of this study is to identify the effect of the size of the blind on the illuminance distribution of the ceiling when the blind slat is controlled based on the discomfort glare. The results of numeral simulations showed that the effect of blind size on the ceiling illuminance is small, when the ratio of blind interval to the blind slat width is between 0.7 to 0.9/

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Sky factor regulation was enacted in 2003. Therefore, the city will change from formed by set-back regulation. This study compared when the building applied set-back regulation with when the building applied sky factor regulation, examined effect on the daylighting of non-uniform skyline base on sky factor regulation. As a result, when the average height of neighboring buildings was high, and Skyline became non-uniform, the possibility that quantity of lighting decreased was suggested.

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n this experiment, the photovoltaic power generation panels stand in the veranda may supplying the power for lighting LED in night time.

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Japan has entered a super-aged society. The lighting in the living environment is desired some improvement that can compensate for the age-related decline in the visual function. It is said that the elderly people are hard to read blue or green letters on black background because of the age-related changes of spectral transmittance of optic lens, especially in the short wavelength. In the high illuminance, however, some of them feel glare because of cataract, and the age-related changes are different in the individual. Therefore, the system which can be changed the light spectrum easily and produce the best lighting condition according to the individual or the situation is very useful for them and the society. Here, we propose that the algorithm and the system with "Color programmable lighting system" which can change the light spectrum, can produce the best lighting environment for the elderly people.

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Recently, there are many cafes in the city and the form and design of them are various. This study aims to show the effect of the density of lattice and interior lighting on evaluation of restfulness at the inside of Machiya Cafe. Subjective experiments were carried out with the 1/6 scales model of Machiya Cafe. Subjects evaluated 60 combinations which consist of 10 densities of lattice, 2 illuminances (501x, 2001x) and 2 color temperatures (3000K, 5000K) at day and night. It was showed that the moderate area rate of opening was the best design for the inside of Machiya cafes.

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When we designed windows and illumination lamps of the residence or office, it is very important to grasp discomfort glare and to take measure for comfort, convenience, Improvement of intellectual productivity, reduction of illumination energy in a room which illuminates.
These days, simulation technology has improved and the design of the illuminations and the windows became easy by simulation. If we can make the discomfort glare appraisal easily which uses the luminance image, it becomes possible high level design.
Then we introduce the evaluation method of the discomfort glare which uses simulation.

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Based on the eco-life and moreover to realize more comfortable life, we aim to create products or a room to control environmental elements such as light, heat, air quality, and sound. However we will not make real trials or a life-size room, but create them in the digital space on the computer. A high-accuracy simulation technology of a light environment, which we name VRAD (VR Aided Design) , has been developed. This paper describes the accuracy and functions of VRAD, and the dramatic effects to improve the process between planning and designing by applying VRAD from the beginning of creation.

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High power LED is developing a new solid state light source rapidly. The light up has some problem, harmful lighting, cost of high electrical power and maintenance, safety of eye and heat, and so on. We have developed high directional LED illuminators named 'HOLORER-it!' like a LED searchlight. We tried to experiment telecentric lighting to the mountain using a lot of 'HOLORER-it!'. The experimentation was given for view lighti up Mt. Ookusayama at Hamamatsu for two mounths. The result is 'HOLORER-it!' makes a success to light up the mountain partially. We hope it is a new technique of lighting method.

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We studied the simulation of the luminous intensity distribution of a skylight under the CIE standard clear sky. To calculate the luminous intensity distribution, we established the bidirectional transmittance distribution function(BTDF) and the bidirectional reflectance distribution function(BRDF) of optical elements of the skylight based on their measured gonio spectral transmittance and gonio spectral reflectance, and did bidirectional ray-trace simulation using BTDF and BRDF. The obtained luminous intensity distribution data make estimation of illumination distribution under the skylights easy as in the case of artificial lighting.

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To create active atmosphere, developement of high correlated color temperature, over 10,000K lamps are increasing all over the world. On the other hand, it is expected that high correlated color temperature lamps is very applicable for street light, because mespic lumiosity curve has its peak ato shorter wavelength region than photopic luminosity curve. As result, we get a conclusion that 12000K is the best among 5000K, 12000K, 17000K and blue monochromatic fluoresecent lamps.

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Study on the intervals and brightness of leading light

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The car accident occurs easily at nighttime, and the fatal accident ratio occupies half of vicinity especially at nighttime. Moreover, the accident because of the low beam use at dark night is pointed out, and the research are requested. In this research, the CG simulation analysis of the visual information when driving at nighttime was done, and how easiness to see changed with the headlight was analyzed.

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Subjective experiment was conducted to identify the effects of change in light color on visibility at transient dark adaptation. The subjects adjusted their eyes to 2600 cd/m2 of 5000 K for 2 minutes and then they were exposed to all 8 different conditions. The recovery time of visual acuity was measured 3 times each for all condition. All 21 university age students participated as the subjects. The results showed that the change in light color had no significant effects on the recovery time of visual acuity in the case when the luminance stepped into the lower level.

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When the consumption energy is reduced, it is necessary to consider the residence amenity. However, when the resident becomes absent, the consumption energy can be reduced by decreasing a set value. therefore,the energy saving of office lighting by human detection control is assumed to be an effective consumption energy reduction technique.In this study,the effect of the energy saving of office lighting by human detection ccontrol was clarified from the measurement analysis result in the office building really operated,and points of concern in the design to improve the effect of the reduction were brought together.

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It is evaluated that the CO2 exhaust reduction potential in an architectural field is the maximum in IPCC the fourth report WG3 (2007).It is important to examine the strategy that decreases the energy consumption of the buildings, though attention has gathered in groping for alternative energy to the fossil fuel.One of the effective strategies includes control of spectral selectivity and directivity against solar radiation on the building envelope. For the building internal space, appropriate visible solar radiation is effective, because utilization of daylight contributes to the reduction in the consumption of the electricity for the lighting and the air-conditioning cooling load.

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For all lighting devices, LED lighting is chosen for its long-life and for energy-saving. With high color rendering and low glare lighting fixtures, it is well-designed visual environment for the space for gathering people. In addition, it endeavors energy- saving with lighting control system. As well as combination with human detectors, eight lighting patterns are set to the controller, and any users can easily call up the scene by one button.

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Task & Ambient Lighting maintains the lighting quality, and is the lighting with good energy efficiency. The proper illuminance ratio between the working area and the ambient, which is necessary to design Task & Ambient Lighting, is examined based on two methods of subjective experiments. Subjects are 30 persons respectively. The consideration is as follows. (1) It clarifies the relation among the pre-adaptation illuminance, the working area illuminance and the ambient illuminance. (2) It examines the visual task performance and the impression of lighting when Task & Ambient Lighting is applied.

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In this experiment, we found that the shelf illuminance that is about three times as the living space illuminance make display space.

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The situation to which "Brightness feeling of the space" that the horizontal illuminance and the person who is a past brightness design index feel is not corresponding has increased by the diversification of an architectural design and the lighting method. A lot of methods of presuming the brightness feeling of in such and the space are reported. There was Feu value 1 calculated from brightness in the inducement view that Iwai proposed to the one), and the method of simply forecasting this index was described in last year's lighting society nationwide rally. The design technique for improving the brightness feeling of the space from the analysis of the Feu value was examined following last year's report this year.

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Our previous study showed that space brightness, which is immeasurable by horizontal illminance, can be evaluated quantitatively by border luminance of color appearance mode. Other study showed that perceived brightness of a room with chromatic interior decorations is higher than that with achromatic. The purpose of this study is to evaluate effectiveness of interior chromaticness on perceived space brightness by comparing magnitude estimated value of space brightness with border luminance. The border luminance was different corresponding to magnitude estimated value. It was shown that difference of space brightness with interior chromaticness could be evaluated by measuring border luminance.

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In nowadays modern society, modern buildings coexist with traditional buildings. In order to create the illumination color temperature for the traditional building with existing technology, research on this illumination color temperature is necessary. For that purpose, in this experiment, subjects are needed to give evaluation for the lighted up traditional building and using factor analysis, the effect of each color temperature used in this experiment were discussed in this research.

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Visual color perception of luminous lamps inside the private room is surveied.

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The purpose of this study is to examine effects of roof light on resident's impression towards visual environment in a private house which I designed. Plans with natural light in private houses are usually desided by designer's experiences and feelings.We examine effects and impressions of natural light (especially by roof light) and analyze psychological effects on residents in relations to comfort.

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