[in Japanese]

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Since response speed decreases at high-level multiplexing methods are searched for to attain high response speed acceptable for practical use at high-level multiplexing (1/200 duty multiplexing drive). And that using a thinner cell and LC material with lower viscosity achieves this goal.

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We have investigated several liquid crystal display modes from the viewpoint of several display performance characteristics for the application to full color a-Si TFT active matrix LCDs. As the results, the Normally White configuration type TN mode has the best full color display for high contrast ratio and small color shift with changing viewing angle.
Decreasing saturation voltage and improving viewing angle characteristics are residual problems.
A new improved liquid crystal mixture was developed which has relativery large εa, K₃₃/ K₁₁ & K₃₃/ K₂₂ and small K₁₁ & Δn. This mixture has been applied to full color a-Si TFT-LCD which has high contrast ratio (more than 100 : 1) and wide viewing angle (Up-Down 65°, Right-Left 80°, more than 10 : 1 contrast ratio).

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a-Si TFT-LCD is analyzed for electro-optical characteristics where the parameters ΔV_ON, ΔV_OFF, and m₃₀ are newly introduced for both On-and OFF-, and flicker characteristic studies. As for ON-characteristics, the values of ΔV_ON coincided well with the theoretical values derived from the static characteristics of a-Si TFT.
However, for the OFF-characteristics, ΔV_OFF was influenced by leakage or by the electric field between the source bus line and the pixel electrode beside the a-Si TFT OFF-resistance. Also, the virtual increase of ΔV_OFF takes place when ΔV_ON>>>> 0. If the above effects are excluded, ΔV_OFF should correspond to those derived from OFF-characteristics. Furthermore, the m₃₀, parameter can for evaluate flicker as its values coincide well with the visual flicker evaluations.

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A method of controlling molecular alignment in ferroelectric smectic liquid crystal (FLC) cells is described. It uses the combined effects of the following two steps of treatment : (1) oblique deposition of metal oxide, e. g., yttrium oxide, to the substrate surface, and (2) application of an electric field in the process of cooling from the isotropic liquid of the FLC to its chiral smectic C phase. With the combination of the deposition at 60° incidence and the application of a DC field with a strength of about 10MV/m in the cooling process, the FLC molecules are aligned to a uniform pretilt of about 50°. Smectic layers are inclined at 40°-50° to the electrode surface in this cell. When no electric field is applied in the cooling process, on the other hand, the pretilt angle of the molecules is about 15° and the smectic layers are nearly parallel to the substrate surface.

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19V″ Cathode Ray Tubes (CTRs) with phosphor pitch of 0. 31 mm and neck diameter of 36.5 mm have been installed in graphic display monitors with the 1280 × 1024 pixel format. However, to meet user demand for greater compactness, a new Trinitron gun has been developed for 16V″ high resolution CRT with neck diameter of 30.6 mm. A combination of small caliber bi-potential and large caliber Trinitron lenses, complex lens structure, is employed for the new gun in order to obtain the same resolution as the current on 16V″ CRT with 30.6 mm diameter. The spherical aberration coefficient has successfully been reduced by half with optimum gun structures calculated by the finite element method (FEM).
As a result, this gun's spot size at screen center is now as small as that of the conventional Trinitron gun for 36.5 mm neck. The spot size at the screen corner is also well-focused by dynamic focus and well-formed by dynamic electrical magnetic quadrupole.

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On a CRT hard-copy printer, normal analog modulation of the CRT light source does not produce optimum resolution, dynamic range, or tone reproduction on the output video hard-copies. Two new digital driving methods, pulse number and pulse width modulation for CRT emission, improve these pictorial characteristics. The former has superior linear relation of input and output when driving the CRT. Furthermore multiple pulse amplitude effectively shortens printing time. The dynamic range of emission expands sufficiently to expose the film, and the resolution doubles from that obtained by analog modulation.
The output video hard-copies prepared by Hi-Vision signals are very impressive, equalling conventional photographic print quality.

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A Kanji character display was investigated with 5mm square character size.
The display's active substrate is designed by C-MOS technology to introduce the inverter structure as the driver. This structure requires a resistive-sea to prevent surface charging, however, it achieved normal phosphor lighting and relieved the transistor from severe off-current.
The pull-down voltage value was determined by deliberating the turn-off characteristic of active-matrix addressed VFD, which in turn suggested that no exclusive power supply is required.
The device is accessed only with 43-pins by incorporating S-RAM and direct-acess-driving.
The C-MOS structure consumes less power and performs about 3000 cd/m² with a 25V drive. The variation degree of its brightness versus ambient temperature is half that of conventional VFDs.
A hybrid display representing Kanji character and fixed pattern was realized by die-bonding the silicon chip, in addition to fixing the phosphor pattern.

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The 640 × 400 graphic VFD module achieved ultrahigh resolution with a pixel pitch of 0.1875 × 0.225 mm by adopting electrostatic deflection of the single matrix system with wiregrid. The new driving system permits increased vertical resolution, a reduced number of grid driver ICs, and increased luminous characteristic dependency on the driving voltage. Elaborate drive circuit design makes possible image display in halftones by field sequential control. Multicolor display is also available with the combined liquid crystal color shutter (LCCS). Full-color capability with LCCS, and attainment of higher luminance will also receive further study because of the improvements brought by the electrostatic deflection type graphic VFD module.

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A planer electron source has been studied for application to flat panel displays. For the electron source, oxide cathode filaments were used and two types of electrodes besides the filament were investigated for diverging electron flow. One was a projected crease-shaped electrode above which the filament is placed leaving a narrow space and the other was a cylindrical mesh electrode in which the filament was centered.
Uniform planer electron flows in the two types of electrodes were shown under optimum driving conditions. A flat panel display with a fluorescent screen addressed by 10×10 matrix elements was constructed. Using this display, it was shown that these cathodes can adequately be applied to flat panel displays.

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A full color gas discharge panel is still insufficiently bright for use as a high definition display, so increasing contrast or reducing reflectance should be regarded with more importance than increasing brightness, especially for viewing in a light illuminated room.
We propose a panel which has micro color filters coated on inner surface of the faceplate. The each filters transmit lights emitted from the cells and absorb ambient lights of other color components.
We examined nearly three-hundred inorganic chemicals and their coating techniques, and found that the ion exchange (staining) method can form the red filter, and the thick film printing method can form the green and blue filter. A TV picture is displayed on the panel with the following performance : cell pitch ; 0.7 mm ; cell number, 60×60 ; filter transmittance, nearly 70% ; reflectance, 2.6 % ; luminous efficacy, 0.15 lm/W ; brightness, 70cd/m² ; gray level, 8bits ; contrast, 40.

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The green-emitting ZnS : Tb, F thin films were deposited by rf-sputtering. Argon, neon, helium, and an argon-helium gas mixture were investigated as sputtering gases. Crystallinity and dc-electroluminescent (EL) efficiency were studied as a function of gas pressure during sputtering. It was found that good crystallinity and efficient EL thin films can be grown when the sputtering deposition is made at around 4 Pa, using the mixture of 60 %-argon and 40 %-helium as a sputtering gas. At the next stage, ac-EL devices were fabricated in which the ZnS : Tb, F active layer was sandwiched between two insulator layers of Ta₂O₅ : Al₂O₃ compound. The green-color EL device developed in this way exhibits 9600 cd/m² at a driving frequency of 5 kHz.

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A large capacity, 704×1024 dot TFEL display panel with a density of 4.2 lines/mm was fabricated. In this paper, the limitations of large capacity TFEL panel scales and a design technique for TFEL film thickness parameters are described. In this panel for driving, 1024 columns of data are transmitted in parallel in four divided sections of 256 lines each, and 704 rows are interlace-scanned at a frame frequency of 70Hz. In addition, a stacked insulator structure is employed to overcome the breakdown tendency of TFEL panels. As a result, because a clear display of 50 cd/cm² luminance for each selected pixel was obtained without flicker, the feasibility of a large capacity TFEL display panel in established.

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A conventional PPI scope radar using an afterglow CRT requires a light hood because of dimness, making afterglow CRT unsuitable for simultaneous observation by many observers.
To improve such observation I investigated a large scale display of the radar image using a laser and a fluorescent screen. Furthermore, three scanning methods are presented here; the first using a galvanometric X-Y scanner, the second using a rotating prism and a galvanometric radial scanner, and the last being a high speed PPI scope using a polygon mirror scanner with a rotating prism and an organic daylight fluorescent pigment screen.
These experiments showed the best results the high speed PPI method was used. The high speed PPI method is suitable for many observer observation and has luminance of 16.5 cd/m² and 768 scanning lines.

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This paper describes a large scale display device cosisting of many segmented CRT's, and its new drive method.
The display's dynamic drive method is compared with the static drive method, it offers advantages for driving large scale devices with numerous elements.
Device simulation shows that the 2 level dynamic drive method is practical and simple.
A large and high brightness 3.84 m×2.88 m (200″) display is demonstrated, called “Diamond Vision Mark II”, composed of 3, 072 segmented CRTs each with 4×4 elements
Its maximum brightness is 1, 300 cd/m², total system power is 6 kW and total weight is 1.3 t.

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[in Japanese]

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[in Japanese]

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