It was found that, during experiments of diamond growth from CO gas at higher concentrations, it smelled ozone intensively near the view window of quartz. From the fact, the CO gas discharge can be expected as an intense UV emission source. In this study, VUV spectrum for the emission from CO gas discharge was measured. The stability of the discharge and VUV emission was also examined. There were many intense emission peak between 150 nm and 210 nm in the spectrum. The emission intensity increased with decreasing the pressure. The emission spectrum was stable during 60 min discharge although the glass tube was slightly browned due to carbon deposition.

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For earth environment, as the source of ultraviolet ray instead of mercury in the fluorescence lamp, we examine for the possibility of use of nitrogen discharge. As the result, nitrogen discharge lamp have some sharp ultraviolet ray between with a wavelength of 300[nm] to 400[nm].
These ultraviolet rays are applicable to excitation of phosphorous material. If nitrogen discharge is compared with mercury electric discharge using a blue phosphorous material, the luminescence efficiency of nitrogen discharge was the half of mercury discharge. Nitrogen discharge luminescence efficiency may be able to improve by search of a suitable phosphorous material.

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We propose mercury-free cylindrically flat fluorescent lamp, and present its characteristics. Two glass tubes are arranged concentrically. One end of space between two tubes is sealed by glass plate with ring electrode, printed on inner-side of plate, and covered by dielectric layer. Other ends of each tube are sealed, and center electrode is arranged. Filament electrode and printed circular electrode covered by dielectric layer are examined. Filling gas is Xe-Ne-Ar mixture. When rectangular AC voltage is applied for operation, fountain like discharge is occurred. Lamp efficacy of 15 - 20 lm/W is obtained.

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The behavior of the coating material in the fluorescent lamp manufctureing proceess is described. The residual hydroxyl groups depend on the teperature rather than the heating time, and CO₂ adsorbed on alumina is replaced with H₂O in the air at room temperature. The formation of the bicarbonate ion HCO3^-. is referred to the residual hydroxyl groups.

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The sealing glass of a fluorescent lamp tube is sometimes meltdown at the end-of-life when it operated by the electronic ballasts composed of a resonance oscillation circuit. In this study, the phenomena of the electrode at the end-of-life are investigated. Two mechanisms are existed for breakdown of the coil-electrode. The meltdown of sealing glass is caused by the current flowing through the capacitor for resonance oscillation after the coil-electrode breakdown.

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We selected the discharge tube structure and circuit system this time and developed the compact self-ballasted fluorescent lamps which achieved the size equal to an incandescent lamp of A60.

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Considering the point of cost, the driving frequency of the electrodeless discharge lamp should be lowered because high frequency driving (> 1MHz) requires special components for reduction of noise and circuit loss. It is, however difficult to obtain enough electric field to maintain a discharge at low power, therefore it is needed to improve the bulb which enables to maintain a stable discharge.
We investigated the buffer gas condition and driving frequency to cope with maintenance of plasma, so as to realize the low-frequency driven (<480kHz) and low power (<12W, which replaces for 60W incandescent lamp) electrodeless compact fluorescent lamp.

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Conventional electrodeless lamps operate at a frequency range from 200kHz to 10MHz. In this paper we describe the development of a high efficacy, high output, electrodeless fluorescent lamp of low frequency operation of 135kHz. Energizing coil wrapped around a rod-shaped ferrite core and located within the re-entrant tube in the center of the bulb-shaped lamp vessel. The lamp-and-ballast system has 13,800lm light output at 83.6lm/W with 165W input to the ballast.

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Development of dimming electronic ballast with a phase control dimmer for studio lighting

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This system is to lessen the change of color temperature when controlling incandescent lamps (including halogen lamps) for stage lighting.
When a light bulb encloses filaments of various voltages, a filament with low voltage and small power can be turned on first by dimming operation.
The second filament comes up after the color temperature of the first one reaches a specific degree.
Even if the color temperature of the second one is low, the system ensures it by impressing the voltage of the first one higher.
Example) The color temperature is kept at 3000K when the intensity is higher than 45% (lamp with 70V300W and 100V700W filaments, the rated color temperature: 3200K).

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Mercury discharge tubes have been operated by an aperture type micro wave cavity. Carbon dummy load experiment showed the disc type tube absobed higher micro wave power than a spherical tube. But the actual discharge tube experiment showed the disc type discharge tube absorbed less micro wave power than a spherical tube. The cause may be the impedance difference between a dummy tube and an actual one.

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In this report, high efficacy metal halide lamps were studied by microwave (2.45GHz). A microwave cavity resonator with a function of a reflector was designed by the finite element calculation. Rare earth metal halides, mercury and argon were used as filling materials for the high efficacy whitish emission. The dimension of the filling was optimized, and the efficacy, the color temperature and the CRI were 178LPW, 3200K and 68 respectively at 400W lamp input in a 27mm-diameter quartz lamp. Finally, the feasibility of the microwave lamp system as a high efficacy and a long life was discussed.

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Dimming characteristics of mercury-free metal halide lamps were studied. On the condition of a 80mm distance between electrodes, vacuum inside the outer bulb and a horizontal burning position, the lamp performance was measured with the parameter of a bulb dimension, Xe gas pressure and a filling composition. The smaller the inner diameter of the bulb was, the less the change of the color temperature was when dimmed. The change of the color temperature was considered to depend on the inner diameter of the bulb and the operative temperature.

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Development of 400W metal halide lamp with high performance

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Development of 400W Ceramic Metal Halide Lamp

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More compact dimensions are requested for small wattage HID electronic ballasts. High frequency operation has advantageous for miniaturization of electronic ballasts. However, it is necessary to prevent acoustic resonance phenomenon in HID lamps at high frequency operation.
We have developed an innovative technique to prevent acoustic resonances of metal halide lamps by operating at two different frequencies alternatively with a suitable time ratio. With choosing 45 kHz as the first operating frequency and 100 kHz as the second frequency, we have succeeded to drive 20W ceramic metal halide lamp without any acoustic resonances.

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In this paper, a small igniter for low wattage HID lamps is described.
SparkGap and edge-wise winding pulse-transformer are employed in proposed igniter.
The volume of the developed pulse-transformer is reduced to one-third times smaller than conventional pulse-transformer.
As the conclusion, we propose 40% smaller igniter than the conventional igniter.

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This research furthermore has the purpose which develops the illuminant where it is superior in cost performance.Because of that, it develops the illuminant which had feature two dimensional controllable and the large area and plane surface type. In the latest report, corresponding relationship between the opening diameter and gas pressure which give the maximum formation efficiency of the excimer was made clear.
Therefore, in optional gas pressure, it suggests that control of the glow excimer which is high efficiency, stability is possible.In addition excimer intensity per unit cubic measure is several times
predominant by comparison with the former double tube excimer lamp.

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The excimer irradiation device that radiates vacuous ultraviolet rays is being used to the washing process in the semiconductor, liquid crystal production process and even the demand is expanding. The excimer irradiation device pours the substrates glass so that it meets with lamp axis direction. And, that is able to materialize a high washing effect was confirmed, by giving integrating ultraviolet quantity of as that is regular to the substrates glass. We were able to materialize high washing ability, in all of without considering face even nature.

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Excimer Lamp is adopted in the washing process in liquid crystal process.
Excimer lamp the high efficiency and long life are demanded.
Unstable electric discharge causes the efficiency decline. The ultraviolet rays deterioration of quartz cause short life.
The above demand we evaluated the lamp electrode structure and electric discharge analysis of to that are satisfied. The result, lamp structure put quartz with the inside electrode and outside electrode and adopted the one side electric discharge method.
By controlling the inside electrode pitch a stable electric discharge was secured.
We commercialized a long life lamp with high efficiency.

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Liquid crystal substrates size is enlarging the size. Accordingly, even the overall length of lamp becomes long. The distribution of ultraviolet rays strength becomes bad, with that the excimer lamp becomes long. Accordingly, we tested the lamp structure of to that does ultraviolet rays distribution evenly. The result, structure established the gap between the electrode of the quartz pipe and outside. By controlling gap we were able to obtain the good lamp of the radiation distribution of the ultraviolet rays of the lamp. The equal ultraviolet rays power distribution were able to be fixed even to a long lamp.

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Development excimer Lamp is establishing the gap between the lamp and lamp appliance. The ultraviolet rays distribution of axis direction have been improved by it.
On the other hand, Lamp voltage becomes high when the gap becomes big. The bobbin of marketing came not to use it from the relation of resistance voltage by it. Thereupon, we examined the circuit constitution that uses the bobbin of marketing. We solved inverter transformer connection primarily the parallel, Secondarily by making the series. Besides the change of the transformer connection number is effective in seed lamp specification.

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Cluster lamps are light generations using the thermal emission spectrum from clusters, which are created small particles in a high-pressure discharge. It is expected to yield high efficiency and excellent color rendering.
In order for cluster luminescence to take place in electric discharge space, such as, the vapor density of metal atoms exceeds the saturation vapor density, halogen cycle is kept continuously, are considered from the principle of a cluster lamp of operation. In this paper, we describe mainly spectral distribution of cluster radiation, which is affected by the metal oxides.

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The higher-pressure electrodeless mercury-free discharge lamps have been investigated to develop long-life and high-efficacy lamps. It is confirmed that the stable discharge can be sustained in the lamps filled with atmospheric xenon gas by the low-power microwave of 10 – 50 W using the launcher made of the coaxial cable and that the lamp efficacy is around 40 lm/W when the additives such as NaI and ScI3 were mixed with xenon gas. However, The lamp efficacy should be at least 100 lm/W for the practical use. It is considered that the low evaporation pressure of the additives causes the lack of the light intensity from the present lamp, which can be supported by the lamp wall temperature lower than 1000 K. This is originated from such a reason that the microwave power may be too small compared with the lamp volume.

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Recently, the improvement of a response time of Liquid Crystal Displays (LCDs) is required for high-definition LCD-TVs. Cold Cathode Fluorescent Lamps (CCFLs) is using as backlights of LCDs, and phosphors with short decay time is needed for high response-time. However, it is problem that the green phosphor (LaPO₄:Ce³⁺, Tb³⁺) has especially long decay time in commercial tri-color phosphors. Therefore, we study Tb³⁺-doped new green phosphors with short decay time. In this paper, luminescence properties of Tb³⁺-doped phosphor are reported.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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We developed the built in type luminaire.
It has the shading component of a round shape design.
And a down light, an emergency light, a night-light, etc. can be built in the central part of the fixture.

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Luminaire corresponding to the network system which operates a home electricity product by remote control was developed

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[in Japanese]

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In order to give comfortable work environment in office, the brightness for the better atmosphere and control of discomfort glare which cause trouble is indispensable to work.
We performed impression evaluation of space, in order to clarify relation between Unified Glare Rating and sensation of brightness.
The equipment evaluated to two adjoining spaces was installed, and evaluation and analysis were performed according to Scheffe's method of paired comparison.
As the result, it has the good luminosity of balance of the lighting equipment to adapt to Unified Glare Rating regulation, and reconciling brightness and glare control by this equipment was suggested.

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As for the visibility of the critical subject in tunnel lighting, it is common to carry out the field experiment using an actual tunnel. However, it is needed huge cost and a huge human power. So, this paper examined whether visibility evaluation could be performed in CG experiment instead of a field experiment. Consequently, if suitable experiment equipment and a suitable experimental condition were constructed, in order that CG experiment might show the tendency of the same visibility as a field experiment, it turned out that visibility evaluation can be performed by CG experiment.

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To investigate visibility of the critical object using total revealing power need relationship between road luminance and luminance contrast to assure visibility of the critical object. But we never have gotten it for speed condition 80km/h by examination using trial lighting installation. Because of probability for the correct perception for all conditions were more than 75%. We tried an examination using computer graphics. As a result, we found road luminance for Japanese standard is about five times as high as one gotten by CG examination and road luminance by CG examination corresponded one by examination using trial lighting installation.

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Utilization factor on the working plane within shadow is examined under Task Ambient Lighting.

As a result, it is clear that utilization factor is necessary to consider about not only the relationship of position between ambient lights and the working plane, but also the configuration of the fixtures and the shadow caster. And, the coefficient to obtain the utilization factor on the desk considered about the fixtures and the shadow caster from the utilization factor on the virtual working plane approximately was able to requested.

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Recently, the demand of the "Home-Theater" which can experience a powerful image and sound is increasing. Then, we researched the lighting requirements for "Home-Theater". This experiment was used the environment near actual living space. In this instance, we experimented about the simplest lighting environment has only ceiling light.

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Recently, the population of the old aged person shows a tendency to increase in the worldwide level. In Japan, about 25% or more of the population might be an old aged person when becoming 2015 years. Therefore, it is meaningful that we think about all barriers for the old aged person.
In this research, "Ideal way of Barrier-free Lighting in sidewalk" for a healthy old aged person was examined.
We analyzed the effectiveness of auxiliary lightings by using three dimension computer graphics and the computer image processing. As a result, "the brightness difference and the color difference are necessary for the old aged person to perceive the barrier on the sidewalk" was elucidated. This paper discusses the outline of results in this research.

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A visual experiment was carried out to obtain BCD intensity of blinking light. The test light is 4 kinds of waveforms named “(a)Right bowstring wave&rdquot;,&rdquot;(b)Triangular wave&rdquot;, and “(c)Rectangle wave A&rdquot;,&rdquot;(d)Rectangle wave B&rdquot;. Illuminated time and dark time of it are equal, frequency is 0.5Hz. Background luminance is 0.10cd/m². Presentation position is 0 degree and 12 degrees of upper parts.
Analysis of variance was carried out. And, “The effect by the difference in a waveform&rdquot; was accepted at 5% of significant levels. Regardless of the presentation position, result with low BCD intensity was brought at the order of (b), (a), (c), and (d).

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Using of electric lights in the day as well as night. We turn on the electric lights when we do not get enough daylight. If we get enough daylight, the consumption of electric power may be decrease. But the actual condition of electric lights is not clear. We survey on the actual condition of electric lights in the non-living space using a questionnaire. As a result, using of electric lights in the day is many in the non-living spaces of apartment buildings in comparison with detached houses.

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This investigation aims to gain an understanding of the lighting arrangements providing a feeling of security and anticipation in the residential corridor. In this report, we tried to clarify the effect of sequential lighting on the psychological evaluation. Experiments were held with a full-size model consist of corridor, anterior room, and posterior room. Illuminance and luminance were measured at strategic points. The results show that the anterior room lighting effects the evaluation of corridor and posterior room. Evaluation of brightness and glare correlate with luminance and illuminance. Evaluation of walkableness correlates with the minimum illuminance on the floor.

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The purpose of this paper is to show that former adaptation level and elapsed time make an effect on relaxant light. The subject were 10 women. The following results were obtained:
The degree of satisfaction is decided by illuminannce. A difference in the initial adaptation level is explained by a change in the elapsed time.

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The final goal of this paper is to establish a design system of windows and window equipment that achieve balanced flow of visual information between the inside and the outside of a room. For this purpose, the faculties of windows were defined as Daylighting, Viewing, Understanding the outside, Impression of the inside, Interrupting the eyes form the outside. And, the experiment on the subjective evaluation was done under some window-conditions and view-conditions. In this paper, it was ascertained that the evaluation of windows were corresponded to the size and arrangement of windows.

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The final goal of this paper is to establish a design system of windows and window equipment that achieve balanced flow of visual information between the inside and the outside of a room. For this purpose, the faculties of windows were defined as Daylighting, Viewing, Understanding the outside, Impression of the inside, Interrupting the eyes form the outside. And, the experiment on the subjective evaluation was done under some window-conditions and view-conditions. In this paper, it was ascertained that the evaluation of windows were corresponded to the type and distance of windows.

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Last year,New Hi-Efficiency Indirect Lighting Luminaire(Hf54W.Luminaire Efficiency:93.7%) was developed(New Luninaire were attached on Top Wall).This time,New Ceiling Paint(Reflectance:89.3%) for New Hi-Efficiency Indirect Lighting Luminaire was develoved.
[Results]Under New Indirect Ligthing Luminaire(4sets) and New Ceiling Paint condition,
1.Glare and Veiling Reflection phenomena never occurred.
2.In Narrow space room(4 by 4 m, ceiling height: 2.7 m), Horizontal Illuminance(average)(height:0.7m) was 844 lx,and Vertical Illuminance(average)(height:1.2m) was 560 lx.

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The purpose of this study is to examine visual impression of the uniform lighting and the Adjusted-Compound lighting for a room lit form a window and ceiling. The experiment was carried out with two scaled-models designed like office rooms. Subjects were asked to evaluate overall impression of the state of lighting in the model space by comparing two rooms. The results showed that the impressions of the adjusted compound lighting were better than that of uniformity lighting on the items of 'dim-bright', 'dislike-like', 'artificial-natural' and 'closed-open'.

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Considering great effects on physical and energy-saving aspects, daylight must be positively introduced into architectural space. To realize positive utilization of daylighting, daylight simulation must be significant as well as development of various devices for daylighting and management technique. However, exact simulation of daylight is not easy in the practical field of lighting design.
The reason for this seems to be following two points.
(1)Precision level of lighting simulation software
(2)Complicated user interface for practical lighting designer
To overcome these situation, we developed LVECS (Lighting and Visual Environment Consulting System) to improve precise level of daylight simulation.

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To clarify the correlation between the evaluation of apparent brightness on the display and that in the space where the source of light is daylighting, 6 examinees are interviewed about four viewpoints. The degrees of which are evaluated in seven ranks, such as "bright to dark".
By the multiple regression, the evaluation of apparent brightness in the space can be formulated by that on the display, maximum luminance on the display and that in the space.
The multiple correlation coefficient is 0.82 .

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