Address Electrode Research Articles

Improvement of color temperature using independent control of red, green, blue luminance in AC plasma display panel

This paper presents a new driving scheme for the improvement and flexibility of a color temperature without sacrificing a peak white luminance using an independent control of the red (R), green (G), and blue (B) luminance in an alternating current plasma display panel (AC-PDP). The independent control for the R, G, and B emissions can be achieved by selective application of the various narrow auxiliary pulses to the R, G, and B address electrodes during a sustain-period. The auxiliary pulses can control the luminance levels independently from the R, G, and B cells by forming the fast and efficient plasma or by slight disturbing of the wall charge accumulation. By the application of various auxiliary pulses leading to the simultaneous control of each color's luminance, it is observed that the new driving scheme can improve the color temperature from 5396 K to 10 980 K in a 4-in test panel with almost the same peak white luminance as that of the conventional driving scheme.

Self-erasing discharge mode for improvement of luminous efficiency in AC plasma display panel

The current paper proposes a new self-erasing discharge mode to improve the luminous efficiency in an ac plasma display panel (ac-PDP). The self-erasing discharge mode is produced by simultaneous application of auxiliary short pulses to the address electrodes at the falling edges of the sustain pulses. By proper adjusting of the amplitude and width of the auxiliary short pulses, an improved luminous efficiency of 26% and luminance of 9% were simultaneously obtained under the stable driving voltage margin condition (>60 V).

A new driving waveform to improve dark room contrast ratio in ac plasma display panel

A high dark room contrast ratio is necessary for realizing good image quality in ac plasma display panels (PDP). However, the conventional PDPs have low dark room contrast ratio because the background light mainly results from the reset discharges between the address, scan, and sustain electrodes in every subfield. In this study, a new driving method [improved waveform of contrast ratio (ICR)] is suggested to enhance the dark room contrast ratio. The principle of ICR is that the facing discharges during the reset period occur between the scan and address electrodes instead of surface discharges by applying almost the same voltage waveform as the scan voltage to the sustain electrode after the conventional first subfield. Moreover, the reset discharge occurs only for the cells that experienced sustain discharge in the preceding subfield after the first subfield. The dark room contrast ratio of ICR is improved more than 7/spl times/ as compared to the conventional method.

Three-dimensional fluid simulation of a plasma display panel cell

In order to understand the discharge characteristics in an alternating current plasma display panel (ac PDP) and optimize it further, a three-dimensional fluid code (FL3P) has been developed. Using this simulator, various three-dimensional features of discharges are investigated in the sustain mode of PDP. First, the striations of wall charge are observed at both the anode and cathode side. Second, the local efficiency is obtained as a function of position. It is mainly divided into the anode region and the cathode region and highest near the anode center. Finally, the effects of various three-dimensional parameters are studied. As one of the examples showing the effect of electrode shaping, the discharge characteristics of a T-shaped electrode cell are compared with those of a conventional cell. The phosphor on barrier ribs contributes to over 44% of the total luminance, but barrier ribs themselves do not play an important role in the overall discharge efficiency. Address electrode width is not always proportional to the size of the discharge because of the wall loss of the particles to barrier ribs.

19.5 L: Late‐News Paper: Inkjet‐Printed Bus and Address Electrodes for Plasma Display

AbstractA novel inkjet technique for forming bus and address electrodes has been developed. Silver nano‐particles dispersed into organic solvent were employed as a special ink for inkjet printing. Bus electrodes of 50‐μm‐width and 2‐μm‐thickness have been inkjet printed using the nano‐particle ink. The resistivity of the bus electrodes was 2 μΩcm after baking at 300°C for 30 minutes. We have fabricated a PDP test panel using inkjet bus electrodes to study its feasibility.

P‐62: High‐Frequency Driving of Address Electrodes for AC Plasma Display to Enhance the Luminace and Luminous Efficiency

AbstractA novel driving scheme applying high‐frequency oscillating waveform to the data electrodes of the conventional PDP is proposed in this paper. More VUV is generated by the high‐frequency waveform so that the luminance and luminous efficiency could be improved. Under experiments on an 8.5‐inch panel, the luminance is improved and the luminous efficiency is enhanced more than 40%.

P‐64: Improvement of Color Gamut Using New Auxiliary Negative Pulse in AC‐PDPs

AbstractA new auxiliary negative pulse is proposed to improve the color purity by reducing the neon (Ne) emission of 585 nm in an ac PDP. Applying the auxiliary negative pulse to the address electrodes during a sustain‐period induces a new discharge mode that can reduce the Ne emission remarkably. For this new discharge mode, the change in the Ne emission intensity including the discharge characteristics is measured and the corresponding mechanism is also analyzed. As a result, it is found that a color gamut area is expanded by approximately 8.5 % in comparison with a conventional case.

Analysis of the address and sustain discharges in an AC PDP cell using three-dimensional simulation

In the usual two-dimensional (2-D) simulations for the analysis of the plasma discharge in a three-electrodes coplanar-type alternating current plasma display panel (AC PDP) cell, the address electrode is regarded as an infinite plane electrode and the existence of barrier ribs is ignored. We have developed a three-dimensional (3-D) fluid code for the analysis of the plasma discharge in an AC PDP cell, where the address electrode and the barrier ribs can be properly treated. Using this 3-D code, we investigated the dynamics of charged particles and excited species during the address and the sustain periods. Time evolution of the Xe**(/spl ges/6 p states) excited species density profile shows a rounded bright head due to the effect of barrier ribs, which is consistent with the infrared images observed using an image intensified charge coupled device. Sustain voltage ranges for the successful sustenance of display discharges after addressing were obtained using both the 2-D and 3-D simulations through the voltage transfer curve analysis. In addition, the UV luminance and the efficiency changes with the variation of sustain voltages were obtained and compared with those of 2-D simulation.

A modified ramp reset waveform for high contrast ratio in AC PDPs

In general, the background light that is produced during the reset period deteriorates the dark room contrast ratio in AC PDP. In this paper, we propose a modified ramp reset pulse that can reduce the background light to an imperceptible level. In the new reset waveform, the discharges between the scan and sustain electrodes are minimized by applying a positive bias voltage to the sustain electrode and only the weak discharges between the scan and address electrodes are found to occur during the reset period. We also adopted the MgO coated phosphor layer to improve the address voltage margin that was reduced when the bias voltage in the modified ramp reset waveform was applied. As a result, the address voltage margin of 45 V which is the same level of the conventional method was ortained and the dark room contrast ratio was improved up to 7500 : 1.

3‐D simulation of T‐shaped electrode and comparison of results with experiments

Numerical simulation is one of the most useful tools to study gas discharge phenomena that occur in alternating current plasma display panel (AC‐PDP) cell. Most PDP cell simulations have been performed for two‐dimensional cell, is cross‐section along the address electrode. We developed a three‐dimensional PDP simulator and applied it to a T‐shaped electrode cell in order to show the effects of sustain electrode shape that cannot be included in two‐dimensional simulation. The dependence of power consumption on electrode shape and area in the simulation showed the same trend as experiment.

37.3: Analysis of Addressing Characteristics Relative to Cell Dimension and Driving Waveform in AC‐PDP

AbstractDynamic behavior was investigated relative to the address electrode width and its misalignment for pulse‐reset and ramp‐reset waveforms and then compared with simulation results. Whereas, the turn‐on voltage showed a decreasing trend with an increasing sustain voltage in a pulse‐reset driving waveform, it remained basically unchanged under the same conditions in a ramp‐reset driving waveform. With an increasing address electrode, the width turn‐on and mis‐addressing voltage had lower values because of the distribution of a larger wall voltage on the dielectric surface of the scan electrode.In addition, it was found that the turn‐on voltage became lower with a decrease in the misalignment of the address electrode. This was because the more the address electrode approached the center, the more the distribution of the wall voltage increased on the dielectric surface of the scan electrode. Finally, the trend of the addressing voltage was quite different relative to the type of driving waveform.

A new method to reduce addressing time in a large AC plasma display panel

To replace the dual scan system by single scan in large ac plasma display panel (PDP), the addressing time should be reduced by modifying cell structure and/or driving circuits. Moreover, the luminance of the PDP can also be increased with the decrease in the addressing time. In this paper, we suggest the bus and address electrodes with triangular protruding tips in order to reduce the addressing time. Moreover, the addressing time of the ac PDP with these electrodes was investigated experimentally with address and display period separated (ADS) driving method. The experimental results show that the addressing time can be reduced more than 30% compared with the conventional type by modifying the electrodes without reducing the luminance of the PDP.

P‐64: Improvement of Color Temperature Using Address Voltage Pulse During Sustain Period of AC‐PDP

AbstractA new driving technique of applying the auxiliary pulses to only the address electrodes with the blue phosphor layers during sustain‐period is proposed to improve the color temperature of an AC‐PDP. This auxiliary pulses can increase the intensity of blue light, such that the color temperature of an AC‐PDP can be improved without any modification of cell structure and degradation of image quality.

Discharge characteristics with respect to width of address electrode using three-dimensional analysis

A numerical analysis of the microdischarge in a surface-type AC plasma display cell has been made using the time-dependent, three-dimensional (3-D) fluid equations to understand the discharge characteristics. We investigate the breakdown dynamics with the width of address electrode and barrier ribs, because the typical 3-D parameters in an AC plasma display panel (AC PDP) model are the width of address electrode and the barrier ribs. It has been clarified that the width of address electrode has important role of the formation of discharge volume with the wall annihilation by barrier ribs and the accumulation of wall charges on the part of address electrode. The obtained time dependent spatial characteristics of an AC PDP discharge with the width of address electrode and the effect of wall annihilation by barrier ribs will help us to design the optimized AC PDP cells to get stable write and sustain discharges.

New shaped electrodes to reduce addressing time in a large AC plasma display panel

The addressing time can be reduced by modifying cell structure and/or driving circuits in order to replace the dual scan system by single scan in large ac plasma display panel(PDP). Moreover, the luminance of the PDP can also be increased by decreasing the addressing time. In this paper, various shapes of bus and address electrodes have been investigated with the aim of reducing the addressing time in ADS driving method. The experimental results show that the addressing time can be reduced by more than 30% compared with the conventional type by modifying the electrodes without reducing the luminance of the PDP.

Two-dimensional modeling of a surface type alternating current plasma display panel cell: discharge dynamics and address voltage effects

To improve the luminance and efficiency of an alternating current plasma display panel, the direct measurement of infrared and vacuum ultra violet (VUV) imaging is performed to study discharge dynamics. Images show two emission regions. One is the cathode glow and the other is the anode glow. In the course of discharge cycle, the cathode glow propagates toward the outer edge of the electrode, while the anode glow does not propagate. We developed a two-dimensional model to simulate the time evolution of the discharge dynamics. We learned from the modeling results that the dominant role for the propagation of the cathode glow is the ion transport and the electron transport for the anode glow. In addition, the effects of address voltage on the luminance and efficiency are investigated during the sustain period. When the address electrode is floating, VUV output is larger than that of biased conditions, but the efficiency decreases slightly. The comparison of 100 V with 0 V bias shows that biased voltage does not affect the luminance and efficiency at the steady state.

Improvement of luminance and luminous efficiency using address voltage pulse during sustain-period of AC-PDP

To improve the luminance and luminous efficiency of a surface-discharge alternate current plasma display panel (ac PDP), auxiliary voltage pulses were applied to the address electrode during a sustain-period. The luminance and luminous efficiency exhibited maximum values at an address voltage of 100 V and pulse width of 1 /spl mu/s. An improved luminance of 21.4% and luminous efficiency of 24% were simultaneously obtained based on the proper adjustment of the widths and amplitudes of the address voltage pulse. Accordingly, the proper control of the amplitudes and pulse widths of the auxiliary address voltage during a sustain-period can improve both the luminance and the luminous efficiency in a surface-discharge ac PDP.

Dynamics of a coplanar-electrode plasma display panel cell. I. Basic operation

Plasma display panels (PDPs) are a technology for large-area high-brightness flat panel displays. There is considerable interest in improving PDP efficiency by optimizing the cell design, input voltage characteristics, operating conditions and gas mixture. In this article, we report on a two-dimensional computer model for PDPs which has been used to investigate the operation of a coplanar-electrode PDP cell sustained in He/Ne/Xe gas mixtures. The plasma transport equations are implicitly integrated in time to enable simulation of complex gas mixtures and PDP cell designs. To resolve the details of the electron dynamics, the electron temperature is computed by solving the electron energy equation. A Monte Carlo simulation for secondary electrons and a radiation transport model for visible light emission are also employed. The basic operation of the PDP cell is described in this article. The first pulse was usually found to initiate a discharge between the top electrodes and the bottom address electrode, which was grounded. Only after a positive surface charge was formed on the bottom dielectric did the discharge shift to being between the coplanar electrodes. For our conditions, radiation from Xe2* made a larger contribution to exciting the phosphor for visible light emission than radiation from the resonance states of Xe since radiation from Xe2* is optically thin.

Two-dimensional multifluid modeling of the He-Xe discharge in an AC plasma display panel

A numerical analysis of the discharge plasma which forms in an AC plasma display panel cell has been made using time-dependent, two-dimensional multifluid equations to understand the discharge physics of He-Xe discharge. The time dependent distributions of the plasma parameters such as the electron temperature, electron density, various ion densities, and excited state species densities, etc., are obtained during the sustain period in a surface type AC plasma display panel (PDP) cell. Because of its importance in the AC PDP operation, the behavior of the wail charges accumulated on the dielectric surface is also examined. It has been found that a DC bias voltage applied to the address electrode controls the distribution as well as the peak values of the plasma parameters. The reaction analysis showed that the dominant reaction process for Xe ion production is the direct electron impact ionization processes and not the Penning ionization process. The cells which have a smaller electrode gap and larger sustain electrode width could accumulate more wall charges and consequently require less voltage for discharge sustainment.

Measurements of a fabricated micro mirror using a lateral-effect position-sensitive photodiode

The characteristics of a fabricated micro mirror were determined using an optical measurement system. The system consisted of a helium-neon laser, a p-i-n lateral-effect photodiode, and other fundamental optical elements. For testing, we used a micro mirror array (1/spl times/4) in which each mirror was composed of a mirror plate, two torsional flexure hinges, two address electrodes, and two support posts. A mirror plate was designed to a size of 100/spl times/110/spl times/1.5 /spl mu/m/sup 3/ and the hinge size was 20 /spl mu/m long, 5 /spl mu/m wide, and 0.5 /spl mu/m thick. The micro mirror array was fabricated using micromachining technology and a lithography-galvanoformung-abformung-like process using nickel electroplating. The variation in the mirror's deflection angle with applied voltage was measured as a static characteristic. The downward threshold voltage of the 0.5-/spl mu/m thick hinge was 48 V. The step response time, as a dynamic characteristic, was 21.8 /spl mu/s when a 64 V step voltage higher than the downward threshold voltage was applied to an address electrode. The lifetime of the fabricated micro mirror was tested for both unidirectional and bidirectional operation.