Self-ballasted compact fluorescent lamps (SBCFL) are widely used to replace incandescent lamps (IL) for energy saving. We studied the heat-transfer phenomena of outer globe-type SBCFLs by measuring the temperatures of lamp parts, consumption power, luminous output, and by calculating the energy balance. The applied methods are heat-transfer network analysis, and computational fluid dynamics (CFD) using FLUENT^® software. The heat loss increased in reflective globe-type SBCFLs as compared to normal transparent globe-type SBCFLs was estimated at about 3 W when the total lamp power was 22 W constant. This results in a temperature rise of 20 K in the plastic holder, and a maximum of 10K at the electronic part on the circuit board. Accordingly, we have developed a 12 W reflective globe-type SBCFL, which replaces a 60 W reflective IL, not a 22 W SBCFL replacing a 100 W reflective IL, to make importance of the thermal reliability.

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Our objective is to establish a window design system that can achieve a balanced flow of visual information from the inside and to outside of a room. To do this, we must clarify what an acceptable level is. We conducted a survey using a questionaire format on the actual window conditions of the and apartment surroundings. Then, we were able to evaluate the resident’s awareness of public disposure. Based on the results, it was clear that most residents were sensitive to being seen by neighbors or people working in nearby office buildings. Additionally, most residents used curtains or blinds to protect their privacy.

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We have already published several papers describing application of an approximate calculation method for calculating interreflection in a room with fixtures. As a result, it is clarified that the illuminance ratio (illuminance ratio =the floor illuminance in a room with fixtures / the floor illuminance in a room where fixtures do not exist) distribution on the floor does not depend to the luminous intensity distribution curves of the light source. The method is presented for predicting the floor illuminance in a room (we called this the real space) with fixtures and a non-uniform diffuse light source from the floor illuminance in a room (we called this the virtual space) with no fixtures. In the previous paper, we presented that the luminous intensity distribution curves of light source of the narrow angle type and wide angle type can be represented as a polynomial expression with the components of cosine to the kth power and angle α_κ of maximum luminous intensity. This paper proposed a method for predicting luminous intensity distribution curves of the light source when desired floor illuminance distributions is given. (we called this the inverse problem) This inverse problem of lighting design is useful for designing practical rooms, and ito procedures are as follows. First, the floor illuminance distribution of real space is replaced with floor illuminance distribution of virtual pace. Next, the relationship between position of the floor and floor illuminance distribution in a virtual room is expressed by the sixth equation. Finally, the relationship between the coefficient of the sixth polynomical with degree κ and the angle α_κ of maximum luminous intensity of the light source is discussed. As a result, it is clarified that the luminous intensity distribution curves of the light source could be predicted from the coefficient of the equation, which has relation to floor illuminance distribution.

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Although a white surface is a strong cue in the judgement of the color appearance of surfaces, the area of a perceptually white surface under different light sources has not been precisely specified. In this study, the Munsell chips categorized as being in the perceptually white area were determined under two different fluorescent lamps with correlated color temperatures of 3000 and 6700 K under three different environmental conditions: an achromatic room, a japanese style living room, and a modern style living room. The color appearance of the chips surrounding the perceptually white area was also investigated. For all three environmental conditions, the center of the perceptually white area was around the N and 10PB chips with the 6700 K lamp and around the 3PB and 5B chips with the 3000 K one. The number of chips categorized as blue was higher with the 6700 K lamp, whereas that categorized as pink or skin tone was higher with the 3000 K lamp. Comparison of results with the 6700 K lamp with the results using the CIE whiteness equation showed that some of the Munsell chips categorized as white in this study were outside the white area defined by the equation.

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Super high-pressure mercury discharge lamps have been employed as a light source on photolithography exposure process, such as patterning Semiconductors, LCDs and PCBs. These lamps have been used under more than 1.0MPa of internal pressure, and temperatures on the outer surfaces of their bulbs reach more than 500°C. Thus, the safety for their ruptures as well as bulb shapes, materials and the employed conditions must be taken into consideration in bulb design. The authors had investigated the effects of pressure and thermal loads on the bulb ruptures. Furthermore, the optimal shapes of bulbs under the above two factors have been studied. In addition to the two factors mentioned above, It is assumed that the effect of “Residual Stress” on the bulb rupture will be substantial. It has been known empirically that the residual stress of the bulb of the lamps are influenced by the employed conditions and it may be occurred when the bulb temperature at the outer surfaces is more than 900°C. Therefore, the objective of this study is to investigate the effects of the residual stress on the lamp bulb rupture. Firstly, the residual stress in the lamps are observed in the blinking tests. In the experiments, the relationship between the blinking numbers and the residual stress in the bulbs and the temperature distribution at the bulb outer surface were investigated. Distribution of the residual stress was calculated by the FEM under the some experimental conditions and the numerical results were compared with the experimental results. As the results, it was found that the tendency of the experimental results were found to be in fairy good agreements with the calculated results and maximum value of the calculated residual stress was 17 MPa. The values of the residual stress were found to be increased as the temperature and the cooling rate were increased and the direction of the maximum principle stress at the outer surface was opposite to that at the surface. It was assumed from the results that the residual stress was influenced by the temperature and the cooling rate. Furthermore, it was assumed that the residual stress was superposed with the stress occurred due to the internal pressure and rupture might be happened. In addition, the authors propose that the lamps should be used under lower temperature by which the residual stress is not occurred.

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