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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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[in Japanese]

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[in Japanese]

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[in Japanese]

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A 6.7-in. square, full-color, a-Si TFT-LCD with 1, 024 × 1, 024 dots and 153 lines-per-in. resolution has been developed. TFT-LCDs with such large display area and high-resolution have several problems : a decreased scan period, an increased scan-line time-constant, and so on. An advanced scanning method in which contiguous scan pulses overlap each other was adopted for the TFT-LCD. Using this driving method, the TFT channel width is reduced. As a result, the scan line capacitance of TFT-LCD has been reduced to 4/5. Moreover, the scan line has low resistance. This line consists of a straight Mo-Ta alloy main and Al islands. Each Al island is connected with the main line through a via hole in a gate insulator layer. With this structure, scan line resistance has been reduced to 1/2. Using these methods, TFT-LCD has good uniformity and gray scale reproduction over a large display area with high resolution.

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An high resolution, eight color, 38 “projection display has been developed using three ferroelectric liquid crystal light valves (LVs) all with 2000 × 2000 pixels. Displays of high uniformity are attained by using the LVs developed with the ultra-fine precision processing technique and a high resolution optical system. The ultra high-resolution LVs (3.3” diagonal) with the pixel pitch of 30, μm (33 lines/mm) are mounted with LSI driver chips assembled with the newly developed COG technology. The LV, filled with FLCs uniformly aligned by obliquely evaporated SiO layers with 2.0 pm spacing has excellent bistability and is addressed by a two slot multiplexing scheme of 1/2000 duty ratio.
The display's contrast ratio is about 100 : 1 in a memorized state in the center area of the projection screen, in spite of the simplest structure which has no black-matrix layer. We successfully achieved molecular orientation causing black-matrix effect in the non-pixel areas by utilizing specially designed driving scheme (we call it “Field-Induced Black-Matrix”).
This multi-color display with high contrast ratio and excellent color purity has an advantage over the laser addressing LC-LV system especially because its renewal speed is a few order faster.

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Recently, visibility of simple matrix LCDs has been remarkably improved by double layer STN and CSH (Color Super Homeotropic) using ECB mode and homeotropic alignment.
In the area of flat panel display, however, the capability for high duty driving is the key to meeting the market demand for higher information contents. A new technology was developed with optimum combination of the following items.
(1) High birefringence LC material (Δn>0.2) for good transmission rate.
(2) Homeotropic alignment with high anchorage energy and small tilt (tilt angle?0.75°) which gives high contrast at high duty driving.
(3) An optical compensator with high retardation.
As a result, high visibility is realized with high performance including a contrast of more than 10/1, a response time less than 100 ms, a wide viewing angle and 8 gray levels.

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A new concept of antiferroelectric stabilization as a result of intermolecular interaction is presented. The characteristic features of the tristable switching among the electric-field-unwound, tilted uniform states and the so-called 3rd state in the antiferroelectricity stabilized ferroelectric liquid crystals (AFS FLCs) are discussed : 1) The director is parallel to the smectic layer normal in the most stable 3rd state and the alignment is easily attained and well maintained : 2) Because of the absence of permanent spontaneous polarization, the switching is free from the so-called ghost effect, one of the serious problems in SS FLCs : 3) Sharp DC threshold and hysteresis endow the switching with the memory effect : 4) Response time sensitively depends on the applied voltage and may become sufficiently fast : 5) The soft smectic layer assures the quasi-bookshelf layer structure and hence the relatively high contrast ratio : and 6) Regular formation of domains may allow us to attain the gray scale. Since the number of FLC materials showing AFS is increasing, it is worth while to investigate its application to displays and other electro-optic devices.

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In order to develop a compact high definition TV (HDTV) set with liquid crystal projection technology, a new reflective TFT array is proposed. In addition, 2. 3 inch liquid crystal light valves (LCLVs) are fabricated, containing about 1. 36 million pixels.
Furthermore, a new driving method is also proposed which is concerned with not only the TFT array architecture but also with the driving scheme of the TFT array. From the experimental results of image quality of the LCLV projection system, this new method has been clarified to be effective for cancelling the cross-talk from the signal line to the pixels through the source-drain capacitance.

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An enhanced EA (elliptical aperture) lens gun is developed for large screen color picture tubes. The effective lens diameter of the enhanced EA lens is 10.4mm, 30% larger than that of a conventional EA lens. This increase in lens diameter reduces spherical aberration and, thus, spot diameter. Spot diameter at center of the screen is about 20% smaller with the enhanced EA lens than that with the conventional lens.
At the screen periphery, the spot diameter is also reduced by aid of an improved dynamic quadrupole lens system. The structure of the quadrupole lens is quite simple and easy to assemble, and a high sensitivity to correct deflection defocusing (astigmatism and field curvature) is achieved. With application of a dynamic voltage under 1 kVp-p, the aorrection can be acomplished over the entire area of the screen.
Dimensions of elliptical apertures and the quadrupole lens are optimized with help of a 3-dimensional electron beam simulation.

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A new flat CRT is developed by means of multi-line thermal cathodes. Using this method, a large area full-color fiat CRT (30-50 in. diagonal screen) is possible.
This study focuses on production of a full-color flat CRT with a 34 in. diagonal screen, 30 to 60 mm in thickness and having 700×500 pixels. Because of its simple construction, a low production cost can be realized.
Before developing a large full-color display, a prototype with a small screen which displays a mono chrome image in a demountable vacuum chamber is tested. The size of this displayed image is 20 mm×20 mm, and the image has 110×26 pixels, and a 46 ft-L brightness.

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We are developing a large-size high-definition flat-panel CRT to be applied to HDTV. We investigated the essential technologies :, 1) needle pillar structure to make the glass envelope light; 2) multi-staged deflectors to make the deflection sensitivity high and make the deflection distortion small; 3) beam current feed-back systems to make the emission characteristics uniform; 4) beam landing control systems to synchronize the timing of the beam landing to that of the modulation signal; and 5) scanning methods for reducing the color difference between the sections. Based on this research, we successfuly developed an experimental panel that is approximately one-eighth the size of a 40″ panel. As a result of this development, we are quite certain that developing a large-size HDTV panel will also be possible.

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A 17-in. high-resolution color DC plasma display panel, having 480×640 (×3 : trio colors) pixels with 0.54×0.18 (×3) mm² pixel size, has been experimenntally manufactured and evaluated for its possible applications in large size work station terminals. Several new technologies such as the roll-coated self-aligned phospher layer and the new He-Kr-Xe mixed gas, have been studied. This panel has a layered priming-discharge electrode construction. 4096 colors can be obtained by each of the three (R, G, B) colors at a 16 gray level. This panel can be operated by a driving system for conventional Ne-Ar mixed gas type PDP. Luminance of 33 cd/m² (white) and efficiency of 0.025 lm/watt (white) were also achieved.

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We classify cell structures of organic electroluminescent (EL) devices into three categories. The optimization of EL cell structures is performed from the viwpoint of the electrical properties of the carrier transport and the emitter layers. Our results demonstrate that it is possible to apply a large variety of luminescent materials to an emitter regardless of its carrier tranport tendency, if the materials are inserted properly into the selected hole and/or electron transport layers.

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A full-color LED flat display panel has not yet been developed mainly because a blue LED has not yet been developed.
We developed high-brightness SiC blue LEDs (12 mcd at 20 mA) with the LPE method, and applied them to full-color LED lamps by combining them with high-brightness GaP red and green LEDs.
A display panel (2×6 lamp array) was also fabricated using these full-color LED lamps. Any color light ranging from red to blue, purple, or even pure white could be generated by this display panel.

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12-inch 3D-PDP and 9-inch 3D-EL displays having 640×400 dots with a lenticular sheet have been developed. We have demonstrated that 3D moving pictures consisting of four and five parallax images viewed without special glasses are possible. The reproduction of 3D television pictures have produced good results. In addition, computer ray-tracing simulations of a lenticular sheet and subjective evaluation tests of the viewing angle range that permit stereoscopic vision are described.

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A multi-aspect lens-plate 3D image is an image which is determined by its characteristic rays. Because characteristic rays are discrete, the images can be handled in real-time, but with one drawback : sampling errors.
In this paper, sampling errors specific to multi-aspect lens-plate 3D images are investigated both theoretically and experimentally. It is shown that the image is autostereoscopic and independent of the observer's parameters (the position of viewing and the interpupillary distance), if the sampling errors are averaged. The dependences of sampling errors on the basic parameters of both display systems and observers are formulated. To reduce sampling errors, the ratio of the aspect-point separation of a display system divided by the observer's interpupillary distance must be small.
Detailed measurements on depth-sampling errors are made with specimens of images, which are recorded by 3D camera and displayed on a lenticular sheet with predominant sampling errors. Theoretical predictions are confirmed with the experiments. Empirical characteristics of lenticular 3D images are well explained by the theories presented in this paper.

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For digital halftoning of photographs and screened dot pictures, it is advantageous for printers to have a capability for a few gray levels in output image than the conventional bilevel one.
A new multilevel CAPIX algorithm for high quality digital halftoning is developed by expanding the concept of the CAPIX (Correlative density assignment of adjacent pixels), which is widely used for high quality bilevel halftoning in the field of office equipment.
A 4-level CAPIX is simulated and evaluated by comparing it with the bilevel output. The 4-level CAPIX is shown to be very effective in improving the fineness and smoothness in gray level reproduction.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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