Kimio Amemiya

Improved discharge characteristics using MgO single-crystal particles and advanced CEL structure

— Pioneer Corporation introduced plasma-display-panel (PDP) TVs in 2005, which achieved the highest dark-room contrast ratio of 4000:1 at the time. These PDPs had a novel discharge cell structure consisting of a crystal emissive layer (CEL) on a MgO protective thin film. This cell structure is refered to as a CEL structure. Magnesium-oxide single-crystal particles, which have a unique luminance peak around 230–250 nm and a good exo-electron-emission property, were found to be an excellent material for CEL and were utilized in CEL panels. In 2007, newly developed PDP TVs in which CEL was formed on a phosphor layer, in addition to the previous CEL structure, were introduced, and this discharge cell structure is refered to as advanced CEL structure. By using the new cell structure, the opposed discharge characteristics have been drastically improved, and a stable reset discharge has been realized with only a weak opposed discharge. As a result, black luminance has been drastically reduced, and a dark-room contrast ratio of over 20,000:1, the highest ever reported, has been achieved.

35.1: Invited Paper: A 50‐in. Diagonal Plasma Display Panel with High Luminous Efficiency and High Display Quality

Higher Xe content gas has been applied to an improved cell design using “T”-shaped electrode and deep WAFFLE rib. Newly developed 50-in. diagonal wide/XGA panels have a luminous efficacy, a panel luminance and a panel full screen white luminance of 1.8 lm/W, 900 cd/m2 and 200 cd/m2 respectively. The power consumption of the new 50-in. display monitor is 348W. The image qualities, other than luminance, have been also improved by “smooth CREAR” driving method and “pure” color filter. The driving method reproduces 768 gray levels and the gradation on low luminance region is as smooth as 4000-step gray levels. Color gamut reproducing full NTSC area and a bright-room contrast ratio of 120:1 under ambient illumination on the screen of 150 lx have been obtained by the color filter. After all the newly developed plasma displays (PDPs here after) show high display quality and the total display performance of them, as a large-screen TV, excels that of any other display device.

Recent progress in device performance and picture quality of color plasma displays

— This paper will describe the R&D history of color plasma displays (PDPs) at Pioneer. The goals of device performance for color PDPs compared to those of CRTs will be described. The device performance includes luminance, contrast ratio, resolution, gray scale, dynamic false contours, and image quality. In order to improve the device performance described above, the technologies developed by Pioneer will be described. These include T-shaped electrode, WAFFLE rib structure, CLEAR driving method, and high-quality video processing. Finally, the next generation of color PDPs will be described in terms of device performance and new technologies.

21.1: Advanced Discharge Cell Design with CEL Realizing Very High Contrast over 20000:1

A new cell structure has been developed to realize very high darkroom contrast ratio. Crystal Emissive Layer (CEL) is added on the phosphor layers, in addition to that on the MgO layer. As this structure enables stable and very low luminance reset discharge, high contrast ratio over 20000:1 has been achieved in new Pioneers PDP “KURO”.

12.2: Development of 50-in. Diagonal Full HD (1920 × 1080) PDPs

50-inch diagonal Full HD PDPs (1920 × 1080 pixels) have been developed and introduced in the market place. In the development, manufacturing of the fine cell structure has been obtained by the optimization of cell design, materials and process conditions. T & Waffle structure has been employed and shows sufficiently high luminous efficacy. Most important issue of high speed addressing has been solved by CEL structure and its improvement. CEL technology has opened new aspect in higher resolution PDP technology. We expect that it will open new technology area in PDP field.

New high-luminance 50- and 43-in. ACPDPs with an improved panel structure

— New 50- and 43-in. ACPDPs, which have been developed and commercialized in 2001, show high luminance with improved cell structure and higher Xe-content gas. The specific features of the cell structure are “T”-shaped electrodes and waffle-structured ribs, which are same as those of the previous model. Both the cell structure and gas conditions have been optimized. New green and blue phosphors have also been adopted. As a result, the luminous efficacy has been improved up to 1.8 lm/W by using a black stripe. The peak luminance of the 50- and 43-in. PDPs have reached 900 and 1000 cd/m2, respectively, while the power consumption of the 50-in. PDP has been decreased to 380 W, which is 20% lower than that of our previous 50-in. PDP.