Address Electrode Research Articles

Simulated results of plasma discharge in AC plasma display panel with asymmetric electrode

ABSTRACTThe cost of the driving circuit could be reduced in the AC type plasma display if one of the two electrodes on upper plate was grounded and the driving circuits were used at only the other electrodes. However, when this new driving waveforms were applied to the conventional panel structure, it had been found that the misfiring discharge occurred during the sustain period even though the address signal was not applied. Since the misfiring discharge during the sustain period occurred between the scan electrode at the upper plate and the address electrode at the lower plate, it is possible to prevent the misfiring discharge by applying the additional voltage to the address electrode at the time of applying the positive sustain voltage. On the other hand, since the application of the address voltage during the sustain period causes the power loss of the drive circuit and the shortening of the lifetime in the circuit component, a panel having the asymmetric electrode structure in which the width of the scan electrode on the upper plate is narrower than other electrodes has been proposed. The reason for only reducing the width of the scan electrode on the upper plate is to prevent the misfiring discharge area with the facing address electrode on the lower plate. As a result, it could be confirmed that the misfiring discharge was prevented by the asymmetric electrode structure using the discharge and wall charge simulations.

Study on high speed address driving method using two-step address pulses in AC plasma display panel

ABSTRACTA new driving waveform using a two-step address voltage is proposed to shorten the discharge delay time of the address period in the AC type plasma display panel. The shortening of the address discharge delay time can reduce the address period occupying about 70% of the driving time in the AC PDP and in the conventional case, a method to prevent the wall charge loss was used by applying the last voltage of the falling ramp waveform to the scan electrode in the reset period is less than the scan voltage. As the voltage difference between the ramp-down voltage and the scan voltage becomes larger, the discharge delay time is shortened. However, at a high address voltage, a misfiring discharge occurs and a driving voltage margin is reduced. Therefore, we propose a new driving waveform that uses the high address voltage and the two-step voltage level at the address electrode to overcome the breakdown voltage of the address circuit. As a result, the address discharge delay time in one pulse of the address period could be reduced about 300 ns.

Discharge instability in alternating-current display panels (AC-PDPs)

ABSTRACTIn this study, discharge properties of 50-in. alternating current plasma display panels (AC-PDPs) were investigated as functions of the gap of ITO electrodes, the height and width of the barrier rib, and the width of address electrodes. The effects of each component on the discharge instability were studied. The change in the discharge gap of ITO electrode mainly affected the discharge instability, and moving-discharge stain increased with increasing the ITO gap. The moving-discharge stain was strongly related to unexpected opposite (or plate-gap) discharge in the energy recovery(ER)-up period and the main reason was the increase of charge variation in the discharge cells. The discharge instability in the AC-PDPs was dramatically reduced by applying overlapped sustain waveform and ER-coil with a low inductance. Both of overlapped sustain waveform and ER-coil with a low inductance suppressed the opposite discharge during ER-up period, and these reduced the charge variations in the discharge cells. However, these caused an increase in the power consumption and led to a decrease in the discharge efficiency. Consequently, the unexpected opposite discharge during ER-up period is considered as the main reason for the discharge instability, and the low inductance of ER-coil and overlapped sustain waveform effectively suppress the opposite discharge in ER-up period.

Address Discharge Simulation of Additional Pulse Application to Common Electrode in AC PDP

The address discharge simulation and the light waveform are investigated when the additional pulses are applied to the common electrode during an address period in AC plasma display panel. The wall charges in a cell are accumulated on three electrodes during a reset period and those are utilized to produce the address discharge triggering in addition to the externally applied voltage between the scan and address electrodes during an address period. As the accumulated wall charges should be utilized on the overall electrodes to improve the address discharge triggering, the additional pulses are applied to the common sustain electrodes when the scan and address pulses are driven. In this study, the Xe 3P2 energy state to generate the vacuum ultraviolet are simulated when the scan and address pulses on two electrode are applied including the additional pulses on the common electrodes. In addition, the address discharge light waveforms in the conventional and the proposed driving method are measured and compared.

Study on Address Discharge Characteristics Using Wall Charge on Three Electrodes during an Address Period in AC PDP

A modified driving waveform in AC plasma display panel is proposed to improve the address discharge characteristics applying the additional pulses on the sustain electrode during an address period. After a reset period in the driving scheme of an AC PDP, the electrons are accumulated on two front electrodes and the ions are accumulated on the address electrode. Among the accumulated wall charge on three electrodes, the electrons on the scan electrode and the ions on the address electrode are mainly used for the address discharge triggering when the scan and address pulses are applied simultaneously during an address period. Meanwhile, since the constant bias voltage on the sustain electrode is only maintained during an address period, the wall charge on the sustain electrode a little contribute to an address discharge triggering. In this sense, if the electrons on the sustain electrode during an address period are utilized, the improvement of the address discharge characteristics is expected. Therefore, in this study, the additional negative going pulses are applied to the sustain electrode while the scan and address voltages are changed during an address period. In addition, the address discharge characteristics are investigated in accordance with the various voltage height and pulse applying time. Consequently, the production time of an address discharge can be reduced approximately 200 ns under the optimal driving condition compared with the conventional driving waveform.

Heterogeneous 3D integration of hidden hinge micromirror arrays consisting of two layers of monocrystalline silicon

We present a complementary metal–oxide–semiconductor (CMOS) compatible heterogeneous 3D integration process that allows the integration of two monocrystalline silicon layers on top of CMOS control electronics. With this process we demonstrate the fabrication of hidden hinge micromirror arrays from monocrystalline silicon for adaptive optics applications. The piston-type micromirror arrays have the flexures underneath the mirror plates on separate silicon layers. Arrays of 48 × 48 mirror elements with an air-gap between mirror and address electrode of 10 µm were fabricated. The mirrors were found to be drift free and showed no imprinting. A maximum electrostatic mirror displacement of 3 µm is demonstrated.

플라즈마 디스플레이 패널에서 공통전극에서의 벽전하를 이용한 기입방전특성의 향상

A modified driving waveform is proposed to improve the address discharge characteristics using wall charge on the common electrodes in plasma display panel. In the driving scheme of plasma display, after a reset period, the negative charge are accumulated on two front electrodes and positive wall charge are accumulated on the address electrode. As the address discharge during an address period is produced when the scan and address pulses are applied at the same time, negative charge on the scan electrodes and positive charge on the address electrodes are mainly used. On the other hand, as the voltage are only maintained without applying the waveform during an address period on the common electrodes, the wall charge is not used on the common electrodes. In this paper, the address discharge characteristics are investigated with changing pulse applying time and applied voltage amplitude on the common electrodes and consequently the producing time of an address discharge are shortened about 200 ns compared with the conventional driving waveform.

Energy levels of the electrons localized over the surface of an inert film with address electrodes

The problem of searching for the potential energy and the energy spectrum of the electrons localized over the surface of a thin liquid or solid inert film due to address electrodes placed under the film is considered.

Numerical Analysis and Experiment on Discharge Characteristics Under Various Address Electrode Widths in AC Plasma Display Panel

The address-electrode width is an important parameter to affect both the address and sustain discharge characteristics in an ac-plasma display panels (ac-PDPs). It was numerically founded that as the address-electrode width was wider, the capacitance between the sustain and address electrodes (=CAY) increased, but the capacitance between the two sustain electrodes (=CXY) decreased. The resultant changes in the sustain and address discharge characteristics, such as a firing voltage, discharge delay time, and luminance, were examined in the 50 in ac-PDP with a high Xe (>11%) content. The increase in the address-electrode width caused an increase in the firing voltage between the sustain electrodes, which was mainly due to the decrease in the capacitance between two sustain electrodes and the increase in the wall charges accumulation toward the address electrode. In particular, the luminance was observed to increase with an increase in the address-electrode width. As the address-electrode width became broaden, the sustain discharge path was longer toward the address electrode, thereby enlarging the discharge volume. Therefore, it was observed that the IR (VUV) and Ne emissions were increased considerably. Furthermore, these experimental results were confirmed by simulating the electric field strength and Xe ion distribution in discharge cell with respect to the address-electrode width.

Effects of Positive-Biased Conditions of Address Electrode During Sustain Discharge on Permanent Image Sticking in AC Plasma Display Panel

The permanent image sticking phenomena were examined and compared for the two bias conditions of the address electrode during sustain discharge such as the grounded and positive-biased (or floated) address electrodes. To compare the permanent image sticking phenomena for both bias conditions, the differences in the display luminance, chromaticity coordinate, color temperature, infrared emission, and discharge current of the image sticking cells and the nonimage sticking cells were measured. It was observed that the positive-biased or floated address electrodes contributed to mitigating the permanent image sticking in comparison with the grounded address electrode during sustain discharge. This phenomenon appears due to the lesser degradation of the visible-conversion characteristics of the phosphor layer caused by the deposition of lower amounts of sputtered Mg species on the phosphor layers, as confirmed by <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Vt</i> closed curve, atomic force microscope, and photoluminescence analyses.

Fabrication of metallic micromirror using electroplating technology

A nickel micromirror array was designed and successfully fabricated using a thick photoresist as a sacrificial layer and as a mold for nickel electroplating. It was composed of two address electrodes, two support posts and a nickel mirror plate. The mirror plate, which is supported by two nickel posts, is overhung about 10 μm from the silicon substrate. The nickel mirror plate is actuated by an electrostatic force generated by electrostatic potential difference applied between the mirror plate and the address electrode. Optimized fabrication processes have been developed to reduce residual stress in mirror plate and prevent contact between the mirror plate and the substrate, which ensure a reasonable flat and smooth micromirror for operation at low actuation voltage.

Mechanism of permanent image sticking induced by ion bombardment and reduction method for ac plasma display panels

Ion bombardment of the phosphor layer during a sustain discharge was identified as the key factor inducing permanent image sticking and reducing the lifetime of alternating-current (ac) plasma display panels (PDPs). Secondary ion mass spectroscopy (SIMS) confirmed that ion bombardment of the phosphor layer facilitated the re-crystallization of the Mg particles sputtered from the MgO surface during a discharge, thereby degrading the visible conversion of the phosphor layer and eventually lowering the luminance and color temperature. Based on this mechanism, experimental results showed that the re-crystallization of the Mg particles was suppressed when using a positive-biased address electrode to diminish the ion bombardment of the phosphor layer. Consequently, minimizing the ion bombardment of the phosphor layer during a sustain discharge was shown to mitigate permanent image sticking in an ac PDP by suppressing the re-crystallization of the Mg particles.

Influence of Ion Bombardment onto Phosphor Layer on Temporal Image Sticking in Alternating-Current Plasma Display Panel

We found that ion bombardment onto a phosphor layer during a sustained discharge was a key factor in inducing temporal image sticking of alternating-current (AC) plasma display panels (PDPs) through facilitated absorption of H2O onto the phosphor layer. We also found that ion bombardment onto the phosphor layer during the sustain discharge strongly depended on the bias conditions of the address electrode on which the phosphor layers were deposited. As a result, the positive-biased or floated address electrode condition could minimize the ion bombardment onto the phosphor layer during the sustain discharge, thus suppressing the absorption of H2O onto the phosphor layer, and ultimately preventing temporal image sticking.

P‐96: Analysis of Address Discharge Delay Characteristics Using Transient Characteristics of IR Emission Intensity in Plasma Display Panel

AbstractThis paper analyzes the address discharge delay characteristics based on the measurement of the transient IR emission intensity according to the wall charge state after the reset discharge. This measurement result shows that the maximal erasure of the wall charges accumulating on the scan and address electrodes during the negative ramp‐falling period induces the easy transition from the weak discharge to the strong discharge, thereby resulting in shortening the statistical delay time.

A Study on the Lifetime Characteristics in Single-Sustainer Driving of an AC Plasma Display Panel

In this paper, we observe the lifetime characteristics of a single-sustainer-driven ac plasma display panel (PDP) based on the variation of luminance which is one of the important points to be considered for a practical application. It was found that the application of bipolar sustain pulse waveforms for the sustain discharge deteriorated the long-term lifetime characteristics in single-sustainer driving compared to conventional monopolar pulse driving. This phenomenon was investigated through 3-D discharge cell simulation. In the sustain operation using the bipolar sustain pulses, it was found that more amount of ion energy was transferred to the surface of the phosphor layer. Moreover, the temporal variation of the luminance in the PDP is assumed to be related to the phosphor deterioration resulting from the ion bombardment or the redeposition of the sputtered Mg particles from the protecting layer. In order to decrease the deterioration of the phosphor layer, we modified the address electrode potential to be floated during the sustain discharge. The calculated ion energy to the phosphor surface decreased with the modified waveforms in the discharge cell simulation. Furthermore, the same effect was observed in the conventional monopolar pulse driving, which led the improvement of lifetime characteristics. The effect of the modified waveforms was also verified through experiments in the test panel.

New Sustain Waveform for Improving Luminous Efficacy in AC PDPs Having 200- $\mu\hbox{m}$ Electrode Gap

In this paper, we investigate the mechanism of low efficacy of a 200-μm-gap structure in a high driving frequency and suggest a new driving waveform for improving the efficacy. The detailed role of the address electrode during the surface discharge is discussed by measuring the discharge current flowing to each electrode. Our observation reveals that the current flowing to the address electrode increases with driving frequency and it makes the surface discharge be weakened. A new sustain waveform with the floating time has been suggested which can enhance the surface discharge by suppressing the opposite discharge. As a result of adopting the proposed sustain waveform, the luminous efficacy has been improved to around 30% compared with the conventional sustain waveform at the driving frequency of 200 kHz.

Study on Address Discharge Characteristics by Changing Ramp-Down Voltage in AC PDPs

The address discharge characteristics formed when an address pulse is applied in AC plasma display panels are investigated by changing the ramp-down voltage during the reset period. The address discharge time lag can be reduced when the difference between the ramp-down voltage and the scan-low voltage is set at a high value during the ramp-down period because the loss of the wall charges accumulated between the scan (Y) and address (A) electrodes during the reset period is minimized. In addition, the voltage applied to the X electrode during the ramp-down period can prevent the voltage margin from reduction even though applying high voltage difference on the Y electrodes.

Variation of the discharge characteristics in single‐sustainer driving of an AC PDP

Single‐sustainer driving is an AC PDP driving scheme to reduce the circuitry by maintaining the sustain electrode at ground level. To date, however, the research on the discharge characteristics in such driving scheme is insufficient. In this study, the panel performance and discharge characteristics of the single‐sustainer driving scheme were observed while varying the address electrode condition. In single‐sustainer driving, the address electrode is strongly involved in the sustain discharge when the former is maintained at ground level, and the dependence of the luminous efficacy on the sustain voltage is different from that in the conventional driving scheme. The dependence of the luminous efficacy on the sustain voltage appeared similar, however, to that in the conventional driving scheme when the address electrode was floated in single‐sustainer driving. In the investigation of the temporal evolution of the sustain discharge using an IICCD camera, it was found that the sustain discharge in single‐sustainer driving with a floating address electrode is similar to that in the conventional driving scheme, and the strong plasma formation region was located in the vicinity of the MgO surface, which seems to be related to the lifetime of a PDP with single‐sustainer driving. In the investigation of the operation characteristics, the PDP that was operated with a floated address electrode showed a narrower dynamic operation margin, but a longer lifetime was expected.

Effects of Xe content on wall‐voltage variation during address period in AC plasma‐display panel

Abstract— To investigate the influence of the gas condition, especially xenon (Xe) gas, on the wall‐voltage variation in relation to the electric‐field intensity during the address period, the wall voltages were measured under various Xe‐gas content ranging from 11 to 20% by using the Vt closed curve analysis method. It was observed that under a weak electric‐field intensity between the scan and address electrodes, the change in Xe content did not affect the wall‐voltage variation, even at a higher panel temperature of 65δC. However, under a strong electric‐field intensity, the wall‐voltage variations were reduced with an increase in the Xe content, confirming that a higher electric‐field intensity would be required to induce the wall‐voltage variation at a higher Xe content during the address period.

Study on Pulse Waveforms for Improving Voltage Margin and Luminous Efficacy in an AC Plasma Display Panel Having Auxiliary Electrodes

New pulse waveforms applied to an alternating-current plasma display panel (ac PDP) with an auxiliary electrode are investigated for the purpose of improving the panel's operating voltage margin and luminous efficacy. In the proposed pulse waveforms with reciprocal sustain pulses, a pair of positive and negative sustain pulses is applied to the sustain electrodes simultaneously and alternately. A positive auxiliary pulse is applied to the auxiliary electrode immediately after reciprocal sustain pulses. The voltage margin becomes wider, and the luminous efficacy is improved because of the suppression of the discharge toward the address electrode. In the another proposed pulse waveforms with reciprocal sustain and auxiliary pulses, a negative pulse, which is the same as the negative pulse of reciprocal sustain pulses, is additionally applied to the auxiliary electrode when reciprocal sustain pulses are applied. This negative auxiliary pulse can maintain a high level of luminous efficacy because it supports the effect of the auxiliary pulses. The measurement results show that the operating voltage margin is about twice wider than that of the typical pulse waveforms for an ac PDP with an auxiliary electrode; furthermore, the maximum luminous efficacy is able to reach 3.14 lm/W in terms of the measurement of the discharge in a 50-in XGA resolution (0.27 mm × 0.81 mm) panel with a white cell and a gas mixture of Ne+20%Xe.