High‐contrast driving method for advanced CEL structure with magnesium oxide single‐crystal powder in ACPDP

Abstract— A new driving method for an advanced‐CEL‐structure panel has been developed. Picture qualities have been upgraded. Discharge time lags are drastically shortened by priming electron emission from magnesium oxide (MgO) single‐crystal powder, refered to as a crystal emissive layer (CEL). The advanced‐CEL‐structure panel has CEL material on the surface of not only the surface‐discharge‐electrode side but also on the address‐electrode side. This panel structure enables a stable opposed discharge when the address electrode functions as a cathode. By utilizing the opposed discharges in the reset and LSB‐SF sustain periods, the dark‐room contrast ratio has been drastically increased to over 20,000:1, which is higher than five times that of the conventional method, and the luminance of the least‐significant‐bit sub‐field (LSB‐SF) is as low as 0.1 cd/m², which is one‐fourth that of the conventional method. The high‐picture‐quality PDP TVs refered to as “KURO” that employs these technologies have been introduced into the marketplace.     

Relationship between exo‐electron currents from MgO thin film and statistical delay time in ACPDPs

Abstract— The exo‐electron currents from a ACPDP test panel with or without MgO crystals sprayed on MgO film were measured directly after eliminating of the wall‐voltage effect. An inverse relationship was established between the statistical delay time and exo‐electron currentfrom the MgO cathode film. The spraying of MgO crystals on MgO thin film was observed to reduce the statistical delay time dramatically even for the same exo‐electron currents measured. The shift of the inverse curve may be attributed to an increased discharge success probability by the MgO crystals sprayed.     

A single‐cell‐gap transflective liquid‐crystal display using different pretilt angles in transmissive and reflective regions

Abstract— A single‐cel l‐gap transflective liquid‐crystal display with two types of liquid‐crystal alignment based on an in‐plane‐switching structure is proposed. The transmissive region is almost homeotropically aligned with the rubbed surfaces at parallel directions while the reflective region has a homeotropic liquid‐crystal alignment. For every driving voltage for a positive‐dielectric‐anisotropy nematic liquid crystal, the effective cell‐retardation value in the transmissive region becomes larger than that in the reflective region because of optical compensation film which is generated by low‐pretilt‐angle liquid crystal in the transmissive region. Under the optimization of the liquid‐crystal cell and alignment used in the transmissive and reflective areas, the transmissive and reflective parts have similar gamma curves. An identical response time in both the transmissive and reflective regions and a desirable viewing angle for personal portable displays can also be obtained.     

Optical filters for plasma‐display panels using organic dyes and conductive mesh layers by using a roll‐to‐roll etching process

Abstract— Optical filters with a high shielding capability against electromagnetic (EM) radiation for plasma‐display panels (PDPs) have been studied. We developed optical filters with high conductivity by utilizing a copper‐mesh layer, which was processed by using roll‐to‐roll photolithography and roll‐to‐roll etching. The copper‐mesh layer has a cross‐striped pattern with a surface resistance of 0.05Ω/□ and an opening ratio of approximately 93%. In combination with the copper‐mesh layer, organic dyes were applied to reduce the PDPs unfavorable emissions, such as near‐infrared light, and to control the transmission properties to improve the PDPs picture quality.     

Electronic structure and electrical conductivity of MgO protecting layer in plasma‐display panels: A tight‐binding quantum chemical study

Abstract— The tight‐binding quantum chemical molecular dynamics code, Colors, has been successfully applied to the electronic‐structure calculations of the MgO‐protecting‐layer model in plasma‐display panels (PDPs). The code succeeded in reproducing the band‐gap energy of the MgO crystal structure. The energy gap between the bottom of the conduction band (CB) and the top of valence band (VB) was 7.45 eV, which is in quantitative agreement with the experimental and previous theoretical results. The electronic structure of the undoped MgO model and Si‐doped MgO model was also calculated. The impurity level was 2.15 eV lower than that for the bottom of the CB. This result was in qualitative agreement with recent cathodoluminescence measurements. In addition, we have already succeeded in developing a novel electrical conductivity simulator using the spatial distribution of the probability density of wave functions obtained from the tight‐binding quantum chemical molecular dynamics code, Colors. The electrical conductivity of the MgO‐protecting‐layer model was estimated with and without an oxygen defect and a significant change in the electrical conductivity of the MgO‐protecting‐layer materials was observed with the introduction of oxygen defects.