[in Japanese]

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Liquid-crystal displays (LCDs) are now widely used as computer display devices. Among them, twisted nematic (TN-mode) and super twisted nematic (STN-mode) displays are the most popular. The spectral transmittance of these LCDs, however, depends on the gray tone level so the gray tone color becomes bluish. We have therefore investigated the quality of the displays and in this study we focus on face color quality. We prepared test images by using a software program to add blue into the image data. Five different bluish levels were used in simulated TN-mode and STN-mode displays. Nine portraits were selected as the testing images. Test participants were asked to judge the quality of the faces according to a five-grade scale and judge the amount of blue according to an impairment scale. These test results show that face color quality is significantly affected by the bluish level of gray tones and that face-color quality is good when no blue is perceived in the face color. We then compared the simulated face color quality with the gray-tone chromaticity of three current TN-mode LCDs, and we found that two of them will be able to display good face colors.

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Research on shooting conditions of 3D program production for natural 3D images has been continued. In the study, it has been shown that orthostereoscopic conditions bring about no inconsistency between depth information from perspective of the lenses and that from binocular parallax. A newly developed 3D camera is based on orthostereoscopic conditions which results in compactness of the camera (weight 8 kg). At the same time, the new camera has a zooming function and is valuable in many ways, especially sport broadcasting. In this paper, we give an outline of the newly developed 3D HDTV camera and the results of subjective evaluation tests on psychological effects of the images shot by the camera. These tests show that the images shot by this camera are more powerful and comfortable to view than those shot by existing 3D cameras.

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The paper describes the design of an array antenna having a rectangular radiation pattern. The antenna can be applied to mobile communications in urban areas and to car-testing tracks having an oval shape. An elliptical pattern is set as the target pattern for developing the rectangular radiation pattern. The current distribution of the array was calculated by recursive computation using a modified Woodward-Lawson sampling method. The element spacing and the current distribution of arrays having 10-20 elements are given in this paper. To confirm the achievement of the desired antenna characteristics, prototype antennas fed by two different types of excitation were examined. The antennas produced a nearly rectangular radiation pattern.

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Low-temperature poly-Si TFTs have lower mobility and a higher threshold voltage than crystallized i transistors. An integrated data-driver using low-temperature poly-Si TFTs consumes a great deal of power if it is formed using conventional circuits. We have developed an integrated data-driver that uses low-temperature poly-Si TFTs that produce a data-sampling frequency twice as high as the clock frequency. The shift registers in the data-driver are divided into many blocks, and each is driven by an intermittent clock. We investigated the relation between power consumption and the number of divisions to optimize the operating conditions. The optimum number of divisions was found to be eight stages/block. The power consumption of the circuit we fabricated, which generates sampling signals, was decreased to only 16%that of a conventional circuit.

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[in Japanese]

View full abstract

[in Japanese]

View full abstract