All issues
Volume 18 (1994)
- Issue 2 Pages 2_11-
- Issue 1 Pages 1_15-
Volume 18, Issue 2
Displaying 1-6 of 6 articles from this issue
- |<
- <
- 1
- >
- >|
Papers
-
Masaru SUGIMOTO, Toru FUJIOKA, Takahiro INOUE, Hiroshi FUKUSHIMA, Yous ...1994 Volume 18 Issue 2 Pages 2_5-2_10
Published: 1994
Released on J-STAGE: February 25, 2011
JOURNAL FREE ACCESSThe surface structure of the incandescent body effects on the emissivity of the infra-red light. If an adequate surface structure can suppress the infra-red emission, the efficacy of the incandescent lamp could increase. The main purpose of the present work is to measure the change of the infra-red emission due to the surface structure. Tungsten films with submicron-sized deep holes (the diameter of 2-4 hundreds nanometer and the depth of 2-4 micrometers) were prepared and heating them. The spectra of incandescent light were measured at high temperature up to 1400K. We found that the amount of the infra-red emitted from the surface with submicron holes is almost a half of that from a surface with macroscopic holes.View full abstractDownload PDF (716K) -
Hidekazu TANAKA, Yuji IWAHORI, Naohiro ISHII1994 Volume 18 Issue 2 Pages 2_11-2_17
Published: 1994
Released on J-STAGE: February 25, 2011
JOURNAL FREE ACCESSA new estimation approach is proposed to reconstruct the glossy surface shape from shading images. The reflectance property of an object is uniform glossy surface described by Phong reflectance model, and the light source produces a uniform parallel beam and the image projection is orthographic. This approach is a kind of wide range recovery technique and the illuminating direction is varied slightly, and the directional derivatives of image density are obtained. The local surface orientation parameters of the curved and polyhedral objects are estimated from the image density and the directional derivatives by a nonlinear optimization method. The estimated gradient values for Lambertian surface are used as the initial values in the optimization, and they are determined only by the directional derivatives of the image density. The effectiveness of this approach is demonstrated in the shape reconstruction simulations for the polyhedral and curved objects.View full abstractDownload PDF (617K) -
— Application to Spatial Illuminance and Error in Rough Calculation —Sho KAMISAKA1994 Volume 18 Issue 2 Pages 2_18-2_29
Published: 1994
Released on J-STAGE: February 25, 2011
JOURNAL FREE ACCESSBy applying the analyzing method introduced in the author’s last paper, “New Calculating System for Illuminance due to Flat Surface Source (1),” a formula can be developed for various types of spatial illuminance due to a flat surface source, with arbitrary shapes and located at arbitrary positions, using the same method as in the case of horizontal illuminance. Regarding errors between theoretical values of spherical illuminance obtained by this formula and approximation obtained by averaging illuminances in 6 directions, the smaller the subtending angle in the luminous front of the source, such as from flood-lighting, the greater the likelihood for error. However, the degree of the error can be significantly reduced by assuming a minute 26-sided polyhedron which interpolates directions at 45 degrees, and applying a method in which all products of illuminance and area ratio are averaged.View full abstractDownload PDF (1344K) -
Yoshiro AOKI, Takashi IRIKURA, Tetsuo TANIGUCHI1994 Volume 18 Issue 2 Pages 2_30-2_39
Published: 1994
Released on J-STAGE: February 25, 2011
JOURNAL FREE ACCESSStudy on the brightness of airport light systems, especially on how much light is scattered by the atmospheric particles, is important under low visibilities. In this paper, a simulation was programmed to analyze space distribution of scattered light by Monte Carlo method, based on scattering by a single particle calculated through Mie Theory. There is no limitation to the position of particles. Effects of visibility, of particle size distribution, and of light wavelength can be taken into consideration. With this program, we studied the variation of luminance distribution with the change in visibility, position of a pilot looking at the airport and the surroundings when approaching, and so forth. The result shows that the scattering of the airport light may add some influence on the brightness of the airport light in the twilight and at night. The simulation had a slight deviation from the calculation using Koschmieder formula for additional luminance with scattered daylight. Particle size distribution greatly affected airport light scattering, while it had little effect on daylight scattering.View full abstractDownload PDF (1065K) -
Kunio YUASA1994 Volume 18 Issue 2 Pages 2_40-2_45
Published: 1994
Released on J-STAGE: February 25, 2011
JOURNAL FREE ACCESSTo determine traces of oxygen as impurities, existing in conventional incandescent lamps, we investigated the emission of light caused by electric discharges. The total pressure of the gas mixture was 93000 Pa, which consists of approximately 90% of Ar, 10% of N2, and less than 250 ppm of O2. The spectrum decay time of Ar and N2 did not significantly depend on the O2 concentration, while that of O(1S)Ar excimer formed in discharges showed a remarkable dependence; i.e., at the O2 concentration lower than 50 ppm, R (decay constant, [1/sec]) of the excimer was proportional to the O2 concentraiton. The measured decay time well fit the calculation using the Welge and Atkinson equation.5) At O2 concentrations of 50 ppm or higher, R increased with the third power of the concentration. The production of O3 may have accelerated R. Determination of time-dependency of the excimer spectrum enabled determining O2 in conventional incandescent lamps without destroying the envelope.View full abstractDownload PDF (473K)
Committee Report
-
Toru NOGUCHI, Masato OKI1994 Volume 18 Issue 2 Pages 2_46-2_55
Published: 1994
Released on J-STAGE: February 25, 2011
JOURNAL FREE ACCESSThe Illuminating Engineering Institute of Japan (IEIJ) organized the Special Technical Committee of Effective Energy Utilization in lighting in 1991, and made several surveys for almost two years. The aim of this committee was to have a better understanding of the present status of lighting technology in Japan especially from the view point of energy efficiency and thus to find the direction of lighting research. This report presents the summary of the energy situation and energy conservation policy of Japan, the present status of energy efficient lighting equipments, measures to reduce the electrical energy demand for lighting without hindering the quality and the present condition of effective utilization of energy for lighting in Japan.View full abstractDownload PDF (1541K)
- |<
- <
- 1
- >
- >|