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A 2/3-inch 2M-pixel CCD image sensor with and advanced frame interline transfer (A-FIT) structure is proposed in this paper. The new sensor is equipped with both interlaced and progressive scanning to meet the increasing demands for progressive scanning in various fields. The vertical CCD register in the storage area consists of two vertically divided registers so that the sensor can output the signal in progressive mode. The advantage of this structure is that both progressive and interlace scanning can be done without increasing the number of stages of the vertical CCD. An inproved vertical MTF and improved limiting vertical resolution of 1035 TV lines were obtained with a test device fabricated with a three layer poly-silicon process.

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An experimental 2, 000-line image pick-up system using the four-imager pick-up method is studied with the aim of developing an ultrahigh-definition image pick-up system that surpasses a high-definition system. Using existing high-definition pick-up elements and lenses, a 2, 000-line image pick-up experimental system with improved vertical resolution has already been developed In this development, the pixels are offset diagonally between the image pick-up elements of two imagers to make the four-imager pick-up method used to improve resolution even more efficient. In addition, a technique where by spatial sample points are taken to be quincunx samples is studied in an effort to improve horizontal and vertical resolution.
In this paper, we report on our investigations into achieving greater horizontal and vertical resolution by offsetting pixels diagonally using HDTV 2/3-inch 2M-pixel charge modulation devices (CMD) We also report on our success in achieving both a horizontal and vertical limiting resolution of more than 1300 TVL through image pick-up testing.
In regard to the approach used to achieve ultrahigh-definition through the multi-imager method, comparisons were made between two-imager pixel offset high definition and simple multi-pixel high definition. We verified that there was no deterioration in S/N and sensitivity, and that there was a gain in dynamic range In addition, simulation showed a limitation resolution curve that included errors in the mounting position of the prisms for the two-imager pick-up elements. The relation between the limiting resolution point and mounting precision is also studied.

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Converted picture quality by a motion-copensated standards conversion depends on the performance of the motion vector estimation from TV signals. The performance of this motion vector estimation from TV signals in turn depends on the characteristics of input pictures. Therefore, subjective evaluation using several test sequences is important to evaluate the performance of a standards converter, and objective evaluation using general broadcasting programs is important, too. This paper proposes a measure for objective evaluation of artifacts which are generated by motion-compensated standards conversion. The proposed measure for objective evaluation is analyzed, and some converted pictures which are obtained by computer simulation of standards conversion are evaluated using this measure. The relationship between the measure and the artifacts of the converted pictures is considered. We confirm that the proposed measure can roughly represent artifacts in the converted pictures.

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The purpose of this study is to investigate the required lightness and contrast for legibility of reflective liquid crystal displays (LCDs). Thirty subjects rated 65 lightness and contrast combinations displayed on the hard copy that simulate a reflective LCD, under various ambient illuminance conditions The results indicate that a higher contrast ratio is required as the lightness L * of the background is decreased lower than 65 or 70 (i e reflectance is 35-40%). The required contrast ratio is about 5 when the lightness is higher than 65 or 70. The influence of ambient illuminance on subjective legibility of the simulated reflective LCDs is not so obvious when the lightness of the background is higher than 65 or 70 These results suggest that the lightness of the background should be higher than 65 or 70, and the contrast ratio between the characters and background should be at least 5.

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This paper describes a new control system for VCR drums. The system, called the Dynamic Drum (DD) system, has the drum assembly's rotation axis tilted to accurately trace recording tracks for noise-free playback. The tilt angle for each playback speed is coarsely controlled by a rotary encoder; the tilt angle is finely controlled by a detected envelope of playback signals. The 2-step control of the DD enables fast angle determination and high stability even for videotapes recorded on other VCRs. The data for the optimum tilt angle at each playback speed can be saved for coarse tilt angle control.

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A display system requiring no special glasses in a useful technology for three-dimensional (3-D) images. The lenticular display system has demerits such as a non-planar screen and blurred images. In this paper, a new 3-D real-time color display with a holographic optical element (HOE) is described. This simple 3-D display can improve the above-mentioned problems. The advantage of the HOE screen is that the number of presented views is much greater than the number of presented views of an equivalent lenticular display, because the HOE screen can multiplex pixels both horizontally and vertically to display lateral views. This color screen can be made easily and smoothly in the same way as the monochrome screen. The trial HOE screen is 4″×5″ and consists of 384, 000 holograms Therefore, the image size measures approximately 4″×5″, and the resolution is 200×160 pixels×4 views×3 (RGB).

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The constitution of a photoconductive layer and pixel electrodes for an avalanche-type solid-state imager overlaid with an a-Se photoconductive layer is studied. To achieve a stable avalanche phenomenon under high electric fields, a blocking structure against charge injection into the photoconductive layer from the electrodes is required. Pixel electrodes with a sufficiently flat surface are also needed to avoid breakdown caused by the local maximums in the electric field To reduce the electric fields in the vicinity of each electrode, we use an As₂Se₃ layer between the cathode and the a-Se layer, and a LiF-doped a-Se layer between the anode and the a-Se layer. This also reduces the dark current. Flat pixel electrodes are formed by p⁺-layers in a n-type Si substrate By using these techniques, an avalanche multiplication factor larger than 20 is attained on a MOS type linear image sensor overlaid with an a-Se photoconductive layer.

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This study adapted three analyses to spontaneous interblink intervals to investigate the temporal fractal in the human eyeblink. First, periodic regularity was qualitatively investigated with one-dimensional maps. Second, the regularity was quantitatively measured by the Poisson regime test. Third, the temporal fractal dimensions were estimated from the regression coefficients of cumulative frequency distribution of the log-log histograms. The behavior of eyelids was optically measured and transformed into point-series data in three conditions : with no, passive and active stressers respectively. The results were as follows : first, the blinking patterns change mainly in period three or four. Second, the intervals change not at random but with statistically significant regularity. Third, the fractal dimension in subjects with no or passive stressers exhibited great value compared with that in subjects with active stresser. Those results suggest that the spontaneous blink patterns have regularity with various time scales, even though the blink seems to occur randomly, and that the scale which is defined as temporal fractal dimension mainly changes according to the psychological attitudes of subjects.

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To understand the effect of the powder characteristics of screen-printed protective layers on activation, we studied several types of MgO powder using parameters, fabrication methods such as vapor phase oxidation (VPO) and decomposition of Mg (OH) ₂ (DOM), the BET value (particle surface area), and the particle size of the MgO powder. First, powders were analyzed by using FTIR, DSC, and TEM. Results show that VPO powder has a lower activation energy compared to DOM powder because of its high crystallinity, smooth surface, and non aggregated particles. Panels were then fabricated using these powders, and activated. To evaluate activation, we measured the firing voltage as a function of activation temperature and aging time. Panels using VPO powder were activated most easily at temperatures above 300°C and firing voltage stabilized within 20 minutes.

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An approach to gray-level image coding based on a fractal theory of iterated contractive transformations was first presented by A. E. Jacquin in 1989. To capture the redundancy through self-transformability piecewise, this approach employs spatial image partitioning into range blocks of two sizes with a thresholding operation based on waveform distortion. A set of elemental contractive block transformations from domain blocks to range blocks in an image is referred to as “Iterated Function System (IFS)” since its iterative application to an arbitrary initial image produces a definite convergence image as a good approximation of the original image. However, the image region with weak self-transformability would degrade the performance of the IFS image coding considerably. In this paper, we introduce a spatial image partitioning method based on a distortion-rate cost function, and then we study the following two improvement techniques : the extension to three-stage spatial image partitioning with range blocks of four different sizes, and the hybridization of the IFS image coding with a more traditional transform image coding.

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Previously we proposed a DC component suppressing method which adds an extra one-byte data to a data block of fixed bytes and converts information data into channel codewords. In this paper, we propose 8-15 channel coding which has no DC component suppressing capability, and 8-15 modulation method which is based on 8-15 channel coding and DC component suppressing method. The window margin and the minimum interval between transitions of the 8-15 channel data are about 6.6% longer than those of (2, 7) RLL codes, and are theoretically the most suitable length when 8-bit data words are translated into 15-bit codewords. The 8-15 modulation method is superior to the (2, 7) RLL coding in respect to some of their characteristic parameters and suppresses low-frequency components efficiently.

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An image processing method is proposed to automatically extract symmetrical regions from binary and gray-scale images. A symmetrical region is defined as a rectangle whose inner pixel values are almost symmetrical with respect to its center line Position, lengths of two sides and rotational angle of the rectangle are assumed to be unknown In this method, a Genetic Algorithm (GA) is employed to determine the rectangular region In our GA, a set of parameters of a rectangle can be regarded as a chromosome of a virtual living thing. Randomly generated individuals evolve according to natural selection and a good solution corresponding to a symmetrical region is obtained through generation iteration. Arbitrary symmetrical rectangular regions can be extracted by the method without any information about the regions.

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In this paper, we propose an extremely low-power spread spectrum communication system to be applied to effective use of television channels that uses transmitted reference synch. First, we assumed a cable system such as CATV. Second, we evaluated indoor radio communication. We evaluated extremely low-power spread spectrum communication with an experimental system. The processing gain of about 4 dB was confirmed.

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We propose lossless DCT coding in which the transform matrix is modified with short length words, then reversible quantizer is introduced for transform vectors The modification makes lossless com pression coding possible An 8 by 8 lossless DCT picture coding system is shown along with simulation results The algorithm can be applied to a contribution transfer system It is important that lossless DCT is compatible with conventional DCT

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[in Japanese]

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