Address Electrode Research Articles

The effect of self-erase discharge on the luminous efficacy of alternating current plasma display panels

In this work, we studied the effect of self-erase discharge on the luminous efficacy of alternating current plasma display panels. Through discharge current analysis, we observed that self-erase discharge occurred mainly between the sustain cathode and the address electrode, which has an influence on the luminous efficacy. We varied the amount and timing of the self-erase discharge in order to observe the effects on the luminous efficacy. We found that the luminous efficacy could be improved by a self-erase discharge when adjusted to occur right before the main discharge in the small gap structure. In the long gap structure, on the contrary, we could increase the luminous efficacy when we suppressed the self-erase discharge. In addition, we suggest various waveforms to control self-erase discharge as a result of our panel experiments.

7.2: Address Discharge Characteristics of High Luminous Efficacy PDP with SrO Protecting Layer

AbstractWe have achieved low voltage driving and high luminous efficacy by applying SrO protecting layer in PDP. Especially its low voltage characteristics can make it possible to use very high Xe content such as 30% gas at the voltage levels which currently commercialized PDP use. The use of SrO protecting layer can reduce the firing voltage not only between sustain electrodes but also between address and scan electrodes, so that the threshold voltage VAY as well as the address delay in the SrO panel with Xe 30% could be made comparable to those in the MgO panel with Xe 10% with the appropriate modifications in the ramp reset waveform.

13.1: New Single Sustain System with High Voltage Address Driver (Hi‐AD) for Low Power Consumption and Low Cost PDPs

AbstractThis paper presents a novel single sustain PDP with a high voltage address driver (Hi‐AD) that has an address supply voltage equal to the sustain voltage and does not change wall voltage on the address electrode side during sustain periods. The Hi‐AD system reduced the luminance degradation to only 1% after 1000 hours. A power consumption in an all black display condition for the Hi‐AD system is 28 % less than that for a conventional dual sustain system.

Measurement of the properties of a flat-panel gas X-ray detector

Recently, large-area image detectors were investigated for X-ray imaging in medical diagnostic and other applications. In this paper, a new flat-panel gas detector for diagnostic X-ray imaging is proposed, and its characteristics are investigated. Research on flat-panel gas detectors is scarce, because of the difficulties of injecting gas against atmospheric pressure. So almost all gas detectors are designed as a chamber. We made a flat-panel sample by display technique (e.g. plasma display panel, field emission display, etc.). Transparent electrodes, dielectric layer, and MgO protection layer were formed in the front glass. Additionally, X-ray phosphor layer and address electrodes were formed in the rear glass. Dark current, X-ray sensitivity, and linearity as a function of electric field were measured to investigate the electrical properties. From the results, the stabilized dark current density and significant X-ray sensitivity were obtained. A good linearity as a function of exposure dose could be realized in a wide diagnostic energy range. These results mean that the passive matrix-addressed flat-panel gas detector can be used for digital X-ray imaging.

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.

Measurement of exo‐electron emission from MgO thin film of ACPDPs

Abstract— Exo‐electron emission from MgO thin film was measured by attaching a high‐precision current sensor to the address electrode of the rear plate of an ACPDP test panel. The measured results revealed that the exo‐electron emission currents can vary very sensitively with the type of doping elements used in MgO film and the measuring temperature. The activation energy of the exo‐electron emission estimated from the emission curves indicated that the trap levels are between 0.05 and 0.32 eV below the bottom of its conduction band. This suggests that shallow electron‐trap levels within MgO film are mainly responsible for the exo‐electron emission.

Effects of Address-on-Time on Wall Voltage Variation during Address-Period in AC Plasma Display Panel

To explain the variation of the address discharge during an address period, the wall voltage variation during an address period was investigated as a function of the address-on-time by using the Vt closed curves. It was observed that the wall voltage between the scan and address electrodes was decreased with an increase in the address-on-time. It was also observed that the wall voltage variation during an address period strongly depended on the voltage difference between the scan and address electrodes. Based on this result, the modified driving waveform to raise the level of Vscanw, was proposed to minimize the voltage difference between the scan and address electrodes. However, the modified driving waveform resulted in the increase in the falling time of scan pulse. Finally, the overlapped double scan waveform was proposed to reduce a falling time of scan pulse under the raised voltage level of Vscanw, also.

Paper Display Module Having Backside Electrode

This paper presents a paper display module, which is fabricated on a flexible paper substrate by using a printing method. Due to the price competitiveness superior to the existing semi-conducting processes, the printing technology has begun to get into the spotlight as a manufacturing tool in many industrial fields, including printed electronics, flexible displays, PCB circuits, RFID-tag, and so on. The paper display module has 75 segments. The size of each segment is 5.78mm × 4.60mm and the thickness is around 220μm, including paper thickness, 100μm. The substrate is 130gsm paper which is generally applicable to a color laser printer. The printed paper display is more flexible than the radius of curvature, 5mm. For increasing the effective display area ratio, the address and common electrodes are located in the backside of the paper. Thus, the ratio is around 82 %. The fabricating process consists of 6 steps: Via-hole laser drilling; Backside electrode printing; Bottom electrode printing; Dielectric printing; Phosphor printing; Transparent electrode printing. As the electrodes, silver ink was used. The via-holes are automatically filled when the backside electrode and bottom electrode are printed in turn.

Three-Dimensional Emission Characteristics of a Weak Discharge in Reset Period of Plasma Display Panels

Three-dimensional IR emission characteristics of a weak discharge in the reset period were investigated with the specially fabricated 3-D test panel which has a glass prism instead of one flank of a closed wall in AC PDP. Based on the 3-D images of the IR emissions measured in the reset period, the IR emissions from the cathode electrodes were not observed all through the rising and falling ramp reset period. During the falling ramp reset period, the emissions from the X and Ay electrodes, which work as anodes, were seen. Moreover, it was observed that the address obviously discharge occurs between the Y and a part of address (Ax) electrode. These results were experimentally confirmed with the 6-in 3-D plasma display panel.

New Reset Waveform for a Large-Sustain-Gap Structure in an Alternating Current Plasma Display Panel

A new reset waveform for a large-sustain-gap structure in an ac plasma display panel is proposed. In the driving of a large-sustain-gap structure with a conventional ramp reset waveform, we cannot avoid the condition of an address electrode being a cathode, which causes lots of trouble in stabilizing the reset discharge. To resolve these problems, a square pulse instead of the conventional rising-ramp pulse is used. In order to stabilize the strong discharge in which the address electrode becomes a cathode, a priming discharge between the address (anode) and scan (cathode) electrodes is made prior to making a strong discharge between the address (cathode) and scan (anode) electrodes. With this scheme, a minimum address voltage of 60 V when the sustain gaps are 250 and 350 mum, respectively, is obtained. However, the contrast ratio using the square reset pulse is lower than that using the conventional ramp pulse. To improve the contrast ratio, the reset waveforms in each subfield are replaced by selective erase waveforms except for the first subfield. In the case of nonselective reset waveform, the background luminance is 19.4 cd/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , whereas the background luminance of 2.4 cd/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> is obtained with selective reset waveform.

Microplasma array devices with coplanar electrodes operating in neon

Microplasma array devices with coplanar electrodes have been fabricated and operated in neon at pressures up to 684 Torr. The microcavity of the device is composed of a couple of electrodes instead of dielectric or single cathode. The experiment results for the line array with 12 microcavities driven by AC sinusoidal voltage show that the power loading of each microcavity reaches approximately several kW cm −3 and the luminance reaches 2500 cd m −2. The discharge delay time for the devices excited by AC pulse voltage is about 1–3 μs. The lighting patterns of the devices with address electrode validate the addressing ability of the proposed devices.

A new circular waveform for the three-electrode shadow mask PDP

A new type of ac-plasma display panel (PDP) with shadow mask (SMPDP) is presented with a cost effective structure. The standard SMPDP only includes two electrodes: a scan electrode and an address electrode, and the discharge is a vertical discharge between these two electrodes. A three-electrode SMPDP is described with increased design freedom to improved performance. A special circular waveform has been designed for the three-electrode SMPDP which is expected to result in a higher efficiency by combining the vertical discharge and the surface discharge.

교류형 플라즈마 표시키의 발광 효율 개설을 위한 실 구조의 방전 특성 분석

본 논문은 수치 해석을 이용한 교류형 플라즈마 표시기의 발광 효율 개선에 대한 연구를 주 내용으로 하고 있으며, 긴 전극 간격을 가지는 유지 전극들 사이에 2개의 보조 전극을 삽입한 5전극 신 구조에서의 방전 특성에 대해 분석하였다. 2차원의 수치 해석 결과에 의하면 어드레스 전극에 보조 펄스가 인가되는 구동 파형을 적용했을 때, 신 구조는 일반적인 3전극 면방전 구조에 비해 대략 52[%]의 효율 증가를 보였다. 결과적으로 방전 초기에 보조 전극 사이에서 일어나는 방전의 크기는 축소되고 주방전에 해당하는 유지 전극 사이의 긴 간격에서의 방전은 확장될수록 플라즈마 표시기의 유지 방전에 있어서 VUN 생성 효율의 개선 효과는 커진다고 볼 수 있다. 이와 같은 수치 해석 결과에 대한 신뢰성은 실험 결과를 제시함으로써 검증할 수 있다.

P‐140: A Modified Selective Reset‐Waveform to Minimize Wall‐Voltage Variation During Address‐Period in Full‐HD PDP

AbstractThis paper proposes a modified selective reset driving waveform that can lower the potential difference between the scan and address electrodes by applying the address‐bias voltage (Va‐bias) to the address electrode during the application of the rising pulse of Y‐electrode in the selective reset‐period. This address‐bias voltage (Va‐bias) plays a role in suppressing the wall‐charge accumulation on the address electrode during the selective reset‐period, thereby contributing to minimizing the wall‐voltage variation during the address‐period and as such allowing the higher voltage difference (=ΔVy) between the scan low voltage (Vsl) and the negative falling ramp voltage (Vnf) during an address‐period without any misfiring discharge. When adopting the proposed selective reset waveform, the address discharge delay time is observed to be reduced by about 120 ns.

P‐137: Investigation of Discharge Phenomena in AC‐PDPs with an Auxiliary Electrode Using the Vt Closed Surface

AbstractIn this work, a novel Vt closed surface model is proposed to investigate the surface discharge phenomena of AC‐PDPs with an auxiliary electrode. The AC‐PDPs with an auxiliary electrode in this work had a total of four electrodes, the combination of which produced six voltage vectors between two given electrodes. The measured Vt closed surface of this type of AC‐PDP is described 3‐dimensionally due to the additive voltage vectors, and was implemented by combining the VTC curves obtained by measuring the firing voltages. Firing voltages were detected using three electrode selection methods, and the Vt closed surface appeared to be same shape regardless of method. Agreement between the three measurement processes confirms that the Vt closed surface model of AC‐PDPs with an auxiliary electrode has a constant morphology. In addition, a resultant form based on the address electrode among morphologies showed a closed surface composed of ten faces which were represented as a voltage vector derived from the voltage differences of the four electrodes.

P‐131: Discharge Characteristics of Extra Pixel Assistance Structured (EPAS) AC‐PDP

AbstractWe have suggested an AC‐PDP with extra pixel assistance structure using a MgO layer made from nano‐powdered paste. This structure needs an own driving waveform at the end of conventional reset period for improvement of address discharge characteristics. It was demonstrated that the separated discharge space was coated by nano‐powdered MgO paste at rear plate for counter(X‐A) discharge between the sustaining and address electrodes. At this discharge, the priming particles can be supplied into the main discharge space. Therefore, address discharge characteristics can be expected to have faster response characteristics than those for the conventional structures of AC‐PDP.

15.3: Anti‐Electromigration of Lead‐Free Ag/Frit Modified Address Electrodes in PDPs

AbstractWe have studied on the usage reduction and anti‐migration properties of newly formulated lead‐Free (Bi‐based) Ag/Frit modified address electrode (hereinafter VE electrode) systems in PDPs (Plasma Display Panels). It is thought that their high performance such as anti‐migration and the cost‐competitiveness without any loss of performance in paste, process and luminous efficacy are originated from the optimum controlling of Ag/Frit weight ratio and low specific gravity by low Ag contents, respectively. Currently, lead‐free VE electrodes are being applied as main electrode materials of PDP panels fabricated by SDI photo‐imageable patterning process including ultra‐fine resolution models.

21.5L: Late‐News Paper: Measurement of Exo‐Electron Emission from MgO Thin Film of AC‐PDP

AbstractExoelectron emission from MgO thin film was measured by attaching a high precision current sensor to the address electrode of rear plate of test panels of AC‐PDP. The measured results revealed that the exoelectron emission currents vary very sensitively with the type of doping elements used and measuring temperatures. The activation energy of the exo‐electron emissions estimated from the emission curves indicated that the trap levels lies between 0.05∼0.32eV below the bottom of its conduction band. This suggests that shallow electron trap levels within MgO film are mainly responsible for the exo‐electron emissions, rather than deep trap levels like F‐type centers.

High‐efficacy drive of spatial positive‐column‐discharge PDP with delayed D pulses

Abstract— A thick‐film ceramic‐sheet PDP provides a long sustain discharge gap of 0.45 mm, enabling the use of positive column discharges. The discharges are established in the middle of the discharge space and are completely free from touching the surface of substrates. This allows for the reduction in diffusion losses of the charged particles. To further improve the efficacy, delayed D pulses are applied to the address electrodes during the sustain period. Although the pulses only draw a little current, they perturb the electric field, reducing the peak discharge current and hence resulting in higher efficacy and luminance. The efficacy and luminance increase by 35% and 38%, respectively, with the delayed D pulses. These pulses are incorporated into the contiguous‐subfield erase‐addressing drive scheme for TV application. A short gap of 70 μm between the sustain and data electrodes generates a fast‐rising discharge and allows a high‐speed addressing of 0.25 μsec. This provides 18 contiguous subfields for the full‐HD single‐scan mode, with 70% light emission duty. A luminous efficacy of 6.0 lm/W can been attained using Ne + 30% Xe 47 kPa, a sustain voltage of 320 V, and a sustain frequency of 3.3 kHz, when the luminance is 157 cd/m2. Alternatively, the panel can achieve 4.2 lm/W and 1260 cd/m2 by increasing the sustain frequency to 33 kHz.

A Study on Wall-Charge Behavior of Single-Sustain Waveform Based on $V_{t}$ Close-Curve Analysis in AC Plasma Display Panel

The wall-charge behaviors of the conventional and two types of single-sustain waveforms during address and sustain periods are investigated based on a simulated result and a Vt close-curve analysis. The single-sustain waveform means that the sustain pulse having both positive and negative voltage levels is applied only to the single-side electrode, i.e., the scan (Y) electrode in this paper, where the common (X) electrode remains grounded. In the single-sustain waveform, the address discharge characteristics were observed to be improved by applying a higher voltage level without causing a misfiring discharge during an address period. An asymmetric IR emission was observed for both positive and negative sustain pulses during a sustain period, which was caused by the simultaneous discharge, including the plate gap discharge between the scan (Y) and the address (A) electrodes only when applying the negative sustain pulse to the scan (Y) electrode.