Koji Shinohe

5.3: Discharge Observation of Plasma Tubes

The plasma tube array display presents the wall size display with very high luminous efficacy. Discharging in plasma tube was observed to estimate the structure for high luminous efficacy. From the results of the observation, it is estimated that not only the discharge gap but also the discharge cavity effects to the luminous efficacy. With this result new structure was tries and 3.7 lm/W was achieved as the luminous efficacy.

A light and flexible plasma tube array with a film substrate

— The plasma tube array is expected to lead to the realization of wall-sized displays. This method will realize an emissive-type display with a flexible screen and an expandable screen size. We have investigated a plastic film substrate with display electrodes for use as a flexible screen and successfully developed the worlds largest bendable emissive display (1000 × 128 mm). The operating voltage distribution was improved compared to that with a plate substrate, and a sufficient voltage margin was maintained.

18.3: Dynamic Driving Characteristics of Plasma Tubes Array

The plasma tubes array is expected to realize the wall size display. However, as a reflection of our tube designing policy for high luminous efficacy, the basic electrical characteristics of plasma tubes array are different from those of conventional PDPs. Some new driving technologies were developed to make the dynamic driving sequence for conventional PDPs adoptable for this high efficacy plasma tubes array. With these results, a full-colour 1m by 128 mm tubes array composed of 128 plasma tubes with the luminous efficacy of 3.1 lm/W was developed.

High-luminous-efficacy structure for plasma tubes

— The plasma-tube-array display is expected to become a wall-sized display with very high luminous efficacy. The cell design for high luminous efficacy was investigated. Also, discharging in the plasma tube was observed in order to investigate the structure for high luminous efficacy. As the result, a high luminous efficacy of 5.4 lm/W was achieved.

High-efficacy plasma-display designs achieving 5 lm/W

— Under high-Xe-content conditions, the luminous characteristics were evaluated for the sustaining electrode width and the sustaining pulse cycle. It was recognized that the proper designs for them in a high-Xe-content gas mixture make it possible to obtain high luminous efficacy. In this research, it was found that narrower electrodes can gain higher luminous efficacy in high-Xe-content conditions. The dependency of the luminous characteristics on the electrode width was analyzed and the differences of discharge phenomena from low-Xe-content conditions, which explain the dependency on the electrode width, were recognized. In an 8-in. test panel, 5.2 lm/W of the maximum white efficacy was obtained. The found phenomenon that narrower electrodes are more advantageous for the luminous efficacy is favorable in high-definition PDPs.

14.1: Invited Paper: Development of Plasma Tube Array Technology for Extra‐Large‐Area Displays

We developed the basic technology for a plasma tube array that could be used to produce emissive, extra-large-area displays. The cell design for high luminous efficacy was developed and luminous efficacy of 5.4 lm/W was achieved for a 20 cm test tubes array. Basic techniques, such as those to produce the tube structure, flexible electrode substrate, drive waveform, were also developed. A high luminous efficacy of 3.7 lm/W and lightweight of 0.6 kg were achieved for a 43-inches-diagonal test array.

High-luminance 1-m-long plasma tubes for wall displays

The plasma-tube array is expected to realize a wall-sized display. This method will realize an emissive-type display with a flexible screen shape and an expandable screen size. The shape of the plasma tube was investigated to realize high luminance, high luminance efficacy, and high flexural strength. As the result, a cyl indroid tube is proposed to satisfy these demands. An experimental display of 1 m x 128 mm has been developed with these cylindroid tubes and it demonstrated a high luminous efficacy of 3.1 lm/W.