[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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A new head-tracking stereoscopic projection technique that does not require special glasses is proposed. Two LCD color projectors display large and clear stereoscopic images on a 44-inch diagonal lenticular screen (pitch 0.5 mm) at a resolution of 640×440 pixels. An innovative head tracking technique to increase effective stereoscopic display area is introduced. This technique uses only two image signals to create an effective stereoscopic area as wide as conventional techniques using many image signals. Experimental results show that clear stereoscopic images can be displayed, and stereoscopic area width increased to 600mm. Combining this technique with a video-telephone system or remote observation system should provide display accuracy and naturalness which is unattainable by conventional systems.

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In this paper, bandwidth expansion for NTSC chrominance signals through field-sequential transmission of high frequency chrominance components is proposed and studied. The field-sequential system has well-balanced temporal-vertical transmissible frequency bandwidth, is compatible with NTSC, and can be realized by simple hardware. Picture quality is improved for pictures which contain stripes or edges with saturated colors.

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This paper proposes a new method to extract characters automatically from 1/25, 000-scale maps, the scale widely used in Japan. Characters cannot be independently extracted because they are often connected with other figures. Therefore, large objects are divided into several small character candidates utilizing a boundary tracing method. Character candidates are compared to key characters which appear in maps in high number, and key character positions in the given map are obtained. Characters are searched from positions of obtained key characters. Algorithm of character extraction and experimental results are described.

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With regard to automatic irises, we have, in addition to controlling image average brightness level, divided the image into several areas, and employed a system that automatically determines image condition from brightness data of each area and makes the necessary compensation.
By using rules applied to the concepts related to image evaluation and employing “fuzzy reasoning”, we are providing a system that, using the same system resources, can cope with a greater number of images. Performance is improved for many images.

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A 10-inch high-quality 1024 (H) ×768 (V) pixels TFEL display has been developed. It has high resolution (5 lines/mm), high contrast (100 : 1) by use of Pr-Mn oxide black dielectric film, low driving voltage (170V_o-_p) by use of Sr (Zr·Ti) O₃ and BaTa₂O₆ dielectric films with extremely high dielectric constants (ε_s=100 and 22, respectively) and self-healing break down mode, and low shift of luminance/ voltage characteristic by use of CaS dielectric buffer film.
For driving, columns of data were divided into 16 bit low-speed signal by S/P transformation processing, and modulation driving power was reduced by 30% on the average by control of discharge loops. A direct pressure contact method was adopted to connect display electrodes with driver ICs mounted on both surfaces of board.
As a result, a high-performance, high-readability TFEL display with 50 cd/m² pixel luminance and low (25 W_max at 60 Hz frame frequency) power consumption has been realized.

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A New 1.2 Gb/s HDTV digital VTR has been developed to comply with “NHK Guidelines for HDTV Digital VTR”, which met the BTA S-001 standard. As it works at a higher data rata and density than current NTSC-system digital VTRs, low error-rate recording techniques were studied. Integrated detection was selected to satisfy good S/N on recording channel. Multilayered SAF head was developed to mitigate high frequecy loss at 148.5 Mb/s per channel. A 5-stage transversal filter was employed to cope with severe inter-symbol interference at a short wave recording of 0.345μm/b. A special PLL controlled by tape speed was employed.

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It is found that an experimental 18mm camera tube using an amorphous photoconductive target of selenium exhibits high sensitivity with quantum efficiency in excess of unity at applied target electric field of more than 9×10⁷V/m. This phenomenon results from avalanche multiplication in the target. Target thickness is 2μm. When camera tube is operated at applied target voltage of 240V, it shows sensitivity about 10 times greater than that of conventional camera tubes. Additional noise produced by avalanche multiplication is negligibly small. Deterioration of lag and resolution characteristics have not been observed. Light-transfer characteristics (γ) are close to unity up to a signal current of 300 nA. A color camera equipped with the selenium tubes is capable of clear picture reproduction in illumination of 180 lx (iris setting f/4).

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Movement detection for TV signals is described. Object areas are divided using high-frequency components of TV signals. These areas are classified into moving and stationary domains according to the value of frame difference signals.
For movement information, the moving domain uses the absolute maximum value of frame difference within the domain, the stationary domain uses the absolute value of frame difference, and finally, movement coefficient “k” is determined according to movement information value.
Scanning line interpolation process experiments show that movement mis-detection is greatly reduced and picture quality is improved.
The method is useful for achieving higher quality IDTV and EDTV images.

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In this paper, a Rank-Order Filter (ROF) and its application to TV signals are discussed. In order to apply ROF to eliminate impulse noise from NTSC color TV signals, we propose : a) kernal structure suitable for NTSC composite signals; b) theoretical analysis of ROF noise elimination characteristics; c) subjective evaluation method for noise elimination from realtime TV signals. In addition, an experimental noise elimination setup and experimental results of subjective evaluation using ROF LSIs we have developed is described. Finally, it is confirmed that (a) it is effective for NTSC composite signals to employ a kernel in a temporal direction where signals of the same phase color-subcarrier can be sampled and that (b) the results of subjective evaluation are consistent with the calculated results of theoretical analysis.

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This paper proposes an efficient new FM transmission scheme for picture signals. The proposed scheme transmits two TV signals over a single channel for the conventional FM transmission of one TV signal. This scheme employs two new techniques : multiplex of picture signals by using TAT (Time-Axis Transform) bandwidth compression and FM transmission of a differential signal. The SN ratio of the reconstructed picture signal and the bit error rate of the control information are analyzed in the proposed scheme. An improvement in the SN ratio of about 6dB is achieved by making a difference in the picture signal and companding its amplitude. The results of the analysis are applied to multiplex transmission systems for international satellite communication and satellite broadcast. These systems are expected to transmit two TV signals over one transmission channel with an SN ratio of more than 40dB.

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The tape squareness is one of the most important factors to improve the carrier-to-noise ratio in video recorders. The influence of the orientation conditions of Co-γ Fe₂O₃ particles in the magnetic paint on the tape squareness has been investigated experimentally and theoretically. It has been shown that the squareness is affected by the orientation conditions, such as magnetic field strength and position of the magnets for orientation and drying temperatrure. It has also been found that the initial slope of the paint magnetization vs. time of exposure to the magnetic field does not change with the applied field strength and its final magnetization is increased with increasing magnetic field strength.

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[in Japanese]

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