The voltage-pulsing effects in AC plasma display panel

The effect of the voltage pulsing is simulated in AC plasma display panel using various two-dimensional simulation codes. The volume-averaged density increases rapidly because of the large electric field in the AC-plasma display panel cell as the peak voltage is raised. The ignition time and the decaying time of the discharge are related to the external voltage. The space and time variations of the charged particle densities and the potential profile are described for various voltage forms. The ion energy distribution near the cathode-side dielectric which plays an important role in the MgO lifetime and the secondary electron emission coefficient is concentrated to much lower energies than the applied voltage     

Operation of a coplanar-electrode plasma display panel cell

Plasma display panels (PDPs) are composed of miniature gas discharge devices sustained in noble gas mixtures. In this paper, the dynamics of a coplanar-electrode PDP cell are described using results from a two-dimensional computer simulation. During the first voltage pulse, the discharge takes place between the top and bottom electrodes. Due to charging of the bottom dielectric during the first discharge pulse, a surface discharge takes place between the top coplanar electrodes on successive pulses     

Microstructure and discharge properties of Mg-Zr-O protective films in plasma display panel

Mg-Zr-O protective films for plasma display panels (PDPs) were deposited on soda-lime glass substrates by magnetron sputtering method. The effects of Zr doping on both the discharge properties (firing voltage, V_f and the minimum sustaining voltage, V_s) and the microstructure of the Mg-Zr-O films were investigated. The results show that the deposited Mg-Zr-O films retain the NaCl-type structure as the pure MgO crystal. The doped Zr exists in the form of Zr⁴⁺ substitution solution in MgO crystal and an appropriate amount of Zr can improve the surface characteristics of the Mg-Zr-O films effectively. When the Zr atomic concentration is about 2%, the Mg-Zr-O films have the strongest (2 0 0) preferred orientation and the minimum surface roughness. The firing voltage and the minimum sustaining voltage of Mg-Zr-O protective layer are reduced at most by about 25 V and 15 V, respectively, compared with those of the pure MgO film. Mg-Zr-O protective layers with an appropriate amount of Zr are promising to meet the demands of advanced high-vision PDPs.     

Experimental observation of image sticking phenomenon in AC plasma display panel

The itinerant strong sustain discharge that occurs during a sustain period over a few minutes causes image sticking, which means a ghost image remains in the subsequent image when the previous image was continuously displayed over a few minutes. Accordingly, this paper investigates whether the dominant factor in image sticking is the MgO surface or phosphor layer by testing the effects of image sticking in subsequent dark and bright images using a 42-in plasma display panel. When the subsequent image was dark, the image sticking was found to produce a brighter ghost image than the background. Thus, since the luminance of a dark image is produced by the weak discharge that occurs during the reset-period, the higher luminance of the ghost image was mainly due to the activation of the MgO surface. Conversely, when the subsequent image was bright, the image sticking was found to produce a darker ghost image than the background. Thus, since the luminance of a bright image is predominantly produced by the strong discharge that occurs during the sustain period, the lower luminance of the ghost image was mainly due to the deterioration of the phosphor layer.     

New color-enhancing discharge mode using self-erasing discharge in AC plasma display panel

A new color-enhancing discharge mode using a self-erasing discharge is proposed based on an analysis of the Ne emission mechanism in a Ne-Xe gas mixture. The effects of the new color-enhancing discharge mode produced by a ramped-square sustain waveform on improving the color reproducibility are examined in an alternate current plasma display panel (ac-PDP) filled with a Ne-Xe gas mixture. When the ramped-square sustain pulses are applied at 150 kHz, the color purities of the blue and green visible emissions are both improved, thereby expanding the color gamut area by about 5.4% without reducing the luminance.     

A two-dimensional multispecies fluid model of the plasma in an ACplasma display panel

A time dependent, two-dimensional model for simulating the plasma evolution in an AC plasma display panel (AC-PDP) is described. Reaction-convection (mobility)-diffusion equations for charged particles and excited heavy neutral species are solved along with Poisson's equation, a radiation transport equation, a surface charge buildup equation, and an external L-R-C circuit equation using a fully implicit numerical method. Electron-driven rate coefficients are computed with a 0-D Boltzmann solver in the local field approximation. For studying the particle dynamics in pure helium, we consider a reduced model in which radiation transport is ignored and the excited species manifold is collapsed to composite metastable and excited states. The model predictions of breakdown voltage are quite sensitive to the value of the secondary electron emission coefficient assumed and the uncertainties in the electron-driven reaction rates. An initial comparison between the model predictions and I-V measurements from a specially constructed helium-filled panel is made with qualitatively similar behavior. The lack of quantitative agreement can be explained by a combination of uncertainties in the model input data and uncertainty in the initial surface charge state in the experiments     

Decay of metastable autoionization state in a highly charged lithium-type ion

Relativistic wave functions have been used to calculate the probabilities for (1s2s2p)⁴P_5/2-(1s²Kf)²F₅/₂ autoionization and (ls2s2p)⁴P₅/₂-(1s²2s)² S_1/2 magnetic quadrupole transition, together with the lifetimes of the (1s2s2p)⁴P_5/2 states, for lithium-type ions with Z from 10 to 60; the results are compared with measurements and with calculations from literature sources.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 13–18, December, 1977.I am indebted to A. D. Gurchumeliya and L. N. Ivanov for valuable discussions.     

Adiabatic curve of a metastable plasma

Expressions are obtained relating the value of the thermodynamic parameters of a metastable supercooled plasma during adiabatic (isentropic) processes. The dependence of the sound velocity on the plasma parameters is determined.General Physical Institute, Russian Academy of Sciences, Moscow. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 15–20, January, 1994.     

Influence of charge deposition in a field-emission display panel

Field-emission displays (FEDs) have been studied intensively in recent years as a candidate for flat-display panels in the future. In a FED, electrons emit from field emitters. Some electrons may impinge on the insulator surface between cathode and gate electrodes and cause charging of that surface because the yield of secondary electron emission is usually not equal to one. The charging of the insulator walls between cathode and gate electrodes is one of the important factors influencing the performance of a FED. In this paper, a simulation program is used to calculate this charge deposition, electric field distribution and electron trajectories. From the change of the electric field upon charge deposition in the triode region, it is shown that the insulator surface is negatively charged at a low gate voltage, e.g. 20 V. However, positive charge is deposited when the gate voltage is high, e.g. 100 V. The simulations also show that the emission current will increase even further after coating the dielectric with a thin film of a material with a high-secondary emission coefficient such as MgO. If a cone-shaped dielectric aperture is used in a triode, the emission current will decrease after charge deposition. However, the focus performance of the electron beam is improving in this case.     

平板显示技术比较及研究进展

平板显示因具有体积小、重量轻、功耗低、画质好等优点,已被广泛应用于电子仪表显示、车载显示、数码相机、智能手机、个人电脑、电视产品等领域之中。本文介绍了薄膜晶体管液晶显示(Thin Film Transistor-Liquid Crystal Display,TFTLCD)、有机发光二极管Organic Light Emitting Diode(OLED)显示、量子点发光二极管Quantum Dot Light Emitting Diode(QLED)显示及微发光二极管(Micro-LED)显示这几种平板显示技术的结构及原理。从结构、材料、性能、应用几方面对这几种平板显示技术进行了比较。最后给出了这几种平板显示技术的最新研究进展。LCD显示经过多年发展,技术成熟,成本低廉,仍然在显示市场占据主流地位。OLED显示技术摆脱了传统LCD的背光源,开创了自发光显示的未来发展方向。在相当一段时期内,LCD和OLED仍将会共存于市场中,相互竞争和补充。QLED显示和Micro-LED显示这两种显示技术,在理论上较OLED显示具有更好的颜色表现、更长的工作寿命等优势,具有非常广阔的发展前景,将为未来显示行业提供更多更好的选择。     

Thermodynamic characteristics of a metastable plasma

The equation of state is obtained for an ion-ion plasma which is stable with respect to recombination processes. The regions of thermodynamic stability of a nonideal plasma and of mixtures of such a plasma with an ideal plasma are determined by considering isotherms. It is shown that such a plasma-gas mixture possesses elastic properties.General Physics Institute, Russian Academy of Sciences, Moscow. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 8–14, January, 1993.     

两种带电尘埃颗粒的等离子体鞘层玻姆判据

采用流体方程和尘埃充电自洽模型研究了鞘边含有两种尘埃颗粒的等离子体玻姆判据. 通过拟牛顿法数值模拟了鞘边两种尘埃颗粒的存在对尘埃自身充电以及离子马赫数的影响. 两种尘埃颗粒中含量较少的尘埃颗粒数密度的增加, 导致两种尘埃颗粒表面悬浮势一个降低, 一个升高. 含量较少的尘埃颗粒的数密度越多和半径越小, 都会导致离子马赫数增大. 另外鞘边无论何种尘埃颗粒的速度增加, 鞘边离子马赫数都将减小. 关键词： 等离子体鞘层 尘埃颗粒 玻姆判据     

Electron temperature and plasma density in surface-discharged alternating-current plasma display panels

The electron temperature and plasma density at the lateral distance of 125 /spl mu/m from the center of sustaining electrode gap have been investigated by a Langmuir probe along with the high-speed discharge image in coplanar alternating current plasma display panels. The plasma density at the lateral distance of 125 /spl mu/m from the center of sustaining electrode gap is shown to be maximum value of 3.7/spl times/10/sup 11/ cm/sup -3/, whereas the electron temperature is measured to be decreased from 1.8 to 0.8 eV as the gas pressure increases from 150 to 400 torr in this experiment. It is noted that the electron temperatures measured by the Langmuir probe and high-speed image camera are in good agreement with each other within 5% error limit.     

A new laser direct etching method of indium tin oxide electrode for application to alternative current plasma display panel

For cost effective fabrication and time of alternative current plasma display panels (AC PDPs), an indium tin oxide (ITO) layer was patterned directly with a Q-switched diode pumped Nd:YVO₄ laser (λ = 1064 nm). As experimental results, 500 mm/s scan speed with 40 kHz repetition rate was suitable for the application to AC PDP ITO electrode. In comparison with the chemically wet-etched ITO patterns by photolithography method, laser-ablated ITO patterns showed the formation of shoulders at the edge of the ITO lines and a ripple-like structure of the etched bottom. By dipping the laser-ablated ITO films in the chemical etching solution for 30 s at 50 °C, the shoulders were effectively removed without affecting the discharging properties of AC PDP.     

Interactions between metastable Xe atoms in the afterglow plasma

By measurements of the electron energy distribution function in a Xe afterglow plasma, the rate constants of the binary ionizing collisions between metastable Xe atoms were determined. The value of β₂₂ = (7.3 ± 1) × 10^?10cm³s^?1 satisfactorily agrees with the value for a van der Waals capture.     

Coagulation of charged particles in a dusty plasma

An investigation is made of characteristic features in the behavior of small particles in a dusty plasma attributable partly to the suppression of coagulation as a result of monopolar charging for particle sizes smaller than the Debye shielding length and partly to the reduction in the effect of charging for larger particles. Similarity relations linking the plasma composition and particle charge with the parameters of the dust component are used to determine the range of parameters for which the linear approximation of the particle charge as a function of their sizes holds. A modified classical theory of coagulation in the diffusion approximation is used to study some anomalies in the behavior of the particle size distribution. It is established that unlike an ordinary aerosol, in a dusty plasma the dispersion of the distribution and the average particle size may decrease with time. It is shown for the first time that a long-lived “quasi-liquid” state of a dusty plasma may be established as a result of the anomalous behavior of the size distribution function of coagulating charged particles.