All issues
Volume 2 (1978)
- Issue 2 Pages 2_12-
- Issue 1 Pages 1_16-
Volume 2, Issue 2
Displaying 1-5 of 5 articles from this issue
- |<
- <
- 1
- >
- >|
-
Masahide SUENAGA, Mikiya YAMANE1978 Volume 2 Issue 2 Pages 2_2-2_5
Published: 1978
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSBursting of arc tubes is one of the problems to be solved in metal halide lamps which contain sodium iodide as one of the additive compounds. Investigations have been made on a chemical reaction between sodium iodide and fused silica by heating fused silica capsules containing sodium iodide in the temperature range, 900∼1200°C. Two processes were found to be connected with such catastrophe. One was sodium dissolution into fused silica and the other was devitrification of fused silica, which was observed when the capsules contained water vapor as an impurity, or when the capsules contained water vapor as an impurity, or when the capsules were made of fused silica with OH redicals. Both processes were found to proceed remarkably above 1100°C to form many cracks on the inside surface of the capsules. The reaction products were compared with those found in the arc tube which had been operated horizontally at higher-than-rated wattage, and comparatively good agreements were obtained.View full abstractDownload PDF (1160K) -
Akihiro INOUYE1978 Volume 2 Issue 2 Pages 2_6-2_11
Published: 1978
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSWhen impurity gas exists in a discharge lamp, both the breakdown voltage and the positive column field strength increase. Value (E2-E02)/E02, which means an increasing ratio of electron energy loss by impurity gas to that by main gas, is proportional to impurity gas concentration, where E and E0 are the electric field strength in positive column with and without impurity gas, respectively. This ratio depends on electron energy loss mechanism by impurity gas. In Penning mixture gas, electrons lose their energy by exciting main gas atoms to their metastable levels. The metastable atoms lose their energy by the second kind collision with impurity gas molecules. On the otherhand, in the positive column with a current density between 5×10-3 A/cm2 and 5×10-2 A/cm2, electrons lose their energy by direct collision with impurity gas molecules. Impurity gas affects more strongly on the positive column field than on the breakdown voltage.View full abstractDownload PDF (508K) -
Takashi URAYAMA1978 Volume 2 Issue 2 Pages 2_12-2_21
Published: 1978
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe designs and the performances of the chock type constant wattage ballasts are discussed. The fundamental quantities for design, such as the reactance values of the linear chock coil and turns ratio of the saturable auto-transformer related to as function of the auto-transformer secondary voltages under normal operation and variable K, which are indicated by ratios of the magnetizing current of the auto-transformer referred to the secondary to the rated lamp current, besides the line and lamp ratings. It is then carried forward according with the particular specification to design the linear choke coil and the saturable auto-transformer in terms of window and core cross sectional areas, core and copper volumes and others, and then, the electrical characteristics, such as the lamp wattage regulation, the lamp current crest factor, and the ballast losses, are investigated from various points of view, such as variable K, the secondary voltage and the flux density of the auto-transformer under normal operation, coefficient of specific voltage, and others.View full abstractDownload PDF (707K) -
Masahiro MATSUURA1978 Volume 2 Issue 2 Pages 2_22-2_29
Published: 1978
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSWithin the visual field, the visual obstruction usually takes place in case which a transmissive screen exists between the eyes and the visual objects. When the inhomogeneous screen, such as mesh and Venetian blind, is used as the materials for the screen, the phenomenon cutting off the objects partially or the one producing a veiling of light is sometimes observed. In the case, these phenomena are complicatedly observed in both experiment and theory in comparison with the phenomenon observed by the homogenious screen. A Randolt ring and screen material were set up in an experimental room, and the visual acuity of a human subject was measured with regard to the lighting conditions, the organization of the composition of the screen, the movement of the visual objects and the relative positions of the eyes, and the screen and the object. These above-mentioned experiments had the result of confirming the existence of glare effects caused by the inhomogenious screens.View full abstractDownload PDF (849K) -
Masayuki IIZUKA, Kozo ISHINO1978 Volume 2 Issue 2 Pages 2_30-2_40
Published: 1978
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe studies of coherent optics such as optical spatial filtering, optical Fourier transformation, optical holography and its application techniques are now widespread according as the progress and diffusion of laser. On the other hand, many researchers have proposed the various simulation methods of coherent optics by means of the digital computer in stead of using the optical processing systems. In this paper, first of all the basic ideas and many parameters considered in generating the binary Fourier hologram by the computer are briefly reviewed. The authors examine the effect of quantization, in particular, the phase parameter which most influences visual appearance and blur of reconstruction image. Moreover, the results of the computer simulation are compared with that of the optically reconstructed image.View full abstractDownload PDF (1726K)
- |<
- <
- 1
- >
- >|