[in Japanese]

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[in Japanese]

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In order to establish of a high accuracy outdoor antenna gain measuring system in the UHF TV Band, a Four-Stacked Circular-Loop Array Antenna (F. S. L. A) System is proposed and a 8-element F. S. L. A consisting of a driven stacked-loop and parasite loops has its current distribution measured by the image method. Measured data clarifies the radiation mechanism. This antenna's radiation characteristics are investigated experimentally in order to obtain basic production data.
The effects of the proposed system on the problem of eliminating waves reflected from the ground or surroundings are examined in detail. In particularly, field fluctuations of this system are less than about 0.5 dB and improved by 0.2-2.0 dB compared to the other conventional outdoor measuring system. The measured error between available gain and directional gain is less than about 0.3 dB.

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Two expriments are performed to determine the optimal white background color for the positive presentation mode of a VDT screen. The first investigates white background color preference without regard to task. One-hundred twenty-four subjects rate the white background colors of a VDT screen. In addition, twenty-three subjects adjust background color to their preferred color. The second experiment studies changes of preference of white background color after VDT work. Four operators perform data-entry task for three hours during five days, and the results indicate that the prefered white background has a correlated color temperature about 8000 K. This temperature represents a slight decrease along the black body locus after VDT work.

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In order to investigate psychological factors in color impressions, questionnaire surveys based on a semantic differential analysis are carried out. Forty subjects estimated ten combinations of letters and background colors on the CRT screen. Factor analysis of color impressions shows that three factors named “preference, ” “gorgeousness, ” and “visibility” are important in evaluating colors on a CRT screen. “Preference” concerns five elements. These are familiarity, comfortableness, ease of operation, feelings of fatigue and visibility of letters.

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The nature of the mis-landing pattern of shadow mask tubes, eliminable by the smoothsurface lens system used in the photochemical screen depositing process, is discussed.
Mis-landing at a point (x, y) on a panel is defined on a fixed plane, perpendicular to the tube axis, as a deviation of the realized virtual light source from the ideal light source, from where the point on the panel in question is irradiated.
Then the subject is interpreted as a problem of finding the arrangement of the virtual light source which is possible with a smooth lens system.
After suggesting that Malus' theorem in geometrical optics is a fundamental for this purpose, the relation between the virtual light source coodinates u_R (x, y) and v_R (x, y) is derived.
Next, this expression is applied to an inline-dot tube and basic mis-landing patterns which cannot be eliminated are extracted.

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For the purpose of transmitting HDTV signals at 120 or 140 Mbit/s with a compact codec, for practical application, an intrafield DPCM system with an adaptive noise shaping filter and a reflected quantizer is discussed. It was confirmed that a weighted S/N of more than 48 dB was obtained and coding noise was hardly perceptible at an observation distance of 3H (H : height of picture). The hardware of this system was implemented by using high speed three line parallel processing with a modifiable look-up-table. The actual hardware could thus be realized with dimensions 430 (W) ×600 (D) ×300 (H) (mm).

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Caricatured portraits as well as photographs of prominent persons are often used in newspapers and magazines. These portraits sometimes look more like a person than original photographs. The reason the caricature resembles the person is that the caricaturist can duplicate features of a person's face very well. It is difficult for a layman to draw good portraits. The Proposed system can draw portraits from original face photographs. First, a face photograph is input by a TV camera and digitized by an AD converter. The picture is passed through median and Laplacian filtering and the components of the face (eyes, nose, mouth, etc.) are recognized using the slit method. The size and shape of each component is compared with the standard size and shape in order to extract the features of the face. These components are replaced with suitable illustration components and the portrait is completed.

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[in Japanese]

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