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

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     

Study on discharge stability of cost-effective driving method based on V/sub t/ close-curve analysis in AC plasma-display panel

A new cost-effective driving method that can drive plasma-display panel cells without applying any driving waveform to the common electrode is proposed based on a V/sub t/ close-curve analysis. In this driving method, it is very important to prevent a misfiring discharge due to the inversion of the polarity of the wall charges accumulated between the scan and address electrodes. The measured V/sub t/ close-curve showed that a misfiring discharge caused by the polarity inversion phenomenon of the wall charges on the scan and address electrode could be prevented by minimizing the potential difference between the scan and address electrodes by applying a positive auxiliary pulse to the address electrode, especially while applying the positive sustain pulse during a sustain period. As a result, the proposed cost-effective driving method can reduce the driving cost by about 20% through eliminating the common driving board and successfully display various image patterns, such as the white, red, green, and blue patterns, on a 42-in plasma television without any misfiring discharge.     

High-speed driving method using bipolar scan waveform in AC plasma display panel

This paper proposes a new high-speed driving method using the bipolar scan waveform with a scan width of 1 /spl mu/s in an ac-plasma display panel. The bipolar scan waveform in an address period consists of a two-step pulse with two different polarities, i.e., a forward scan pulse with a negative polarity and reverse scan pulse with a positive polarity, which can produce two address discharges, including a primary address discharge for generating wall charges and secondary address discharge for accumulating wall charges. To produce the fast address discharge stably using the bipolar scan pulse during an address period, a new reset waveform is designed based on a V/sub t/ close curve analysis, and the address discharge characteristics examined under various reset and address waveforms. As a result of adopting the proposed driving method, a high-speed address with a scan width of 1 /spl mu/s is successfully obtained when using a checkered pattern on a 4-in test panel.     

Reset-while-address (RWA) driving scheme for high-speed address in AC plasma display panel with high Xe content

A new reset while-address (RWA) driving scheme for a single scan of an XGA grade (1024 /spl times/ 768) ac-plasma display panel (PDP) is proposed to improve the address discharge characteristics with a high Xe gas mixture (15%). To solve the conventional address problem of the gradual decrease in priming particles during an address period, the falling ramp waveform in the reset period is separated into two parts; the first part is applied at the beginning of the reset period and provides the priming particles during the first half of the address period, while the second part is applied in the middle of the address period to provide an additional supply of priming particles during the second half of the address period. As a result of adopting the proposed RWA driving scheme, address discharges were successfully produced within a 1.0-/spl mu/s pulsewidth due to the presence of priming particles throughout the address period.     

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 $muhbox{m}$, 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 $ hbox{cd/m}^{2}$, whereas the background luminance of 2.4 $ hbox{cd/m}^{2}$ is obtained with selective reset waveform.      

Two-frequency drive for AC-refresh plasma display panels

A new drive scheme, with mixed low- and high-frequency drives, has been developed for large-capacity (large number of dots) ac-refresh plasma display panels. Its usefulness for suppressing both firing-voltage increase and luminance-level decrease in a large-capacity panel was confirmed using a practical-size plasma panel. This drive technique can produce a large display panel ( > 400-600 scan lines) with about 50-percent lower power dissipation and higher luminance level than a conventional drive technique. It has been clarified experimentally that these results are due to the sufficient formation of the wall charge at an initial discharge period.     

A new driving waveform to improve dark room contrast ratio in acplasma 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× as compared to the conventional method     

A pulse discharge panel display for producing a color TV picture with high luminance and luminous efficacy

A new addressing method has been studied, making use of the internal memory obtained by operating with repetitive pulse discharges, applied to gas-discharge panels having a three-electrode positive-column structure. Using this method, color TV pictures with 64 gray levels and a contrast ratio of 42:1 have been produced on a panel with 59 × 50 cells, each color picture element consisting of four cells (two green cells, one red, and one blue). In operation a peak area luminance of 70 fL and a luminous efficacy of 0.35 lm/W were obtained with an average power consumption of 110 mW/cm².     

A gas discharge display for compact desk-top word processors

A flat dc-cyclic, gas discharge panel is described that employs a simple three-layer structure with a priming and a display anode in each cell. The priming anodes act in conjunction with phased cathodes to cause sequential breakdown of cells within a group of cell columns and the short-duration, low-current (and, therefore, low-brightness) discharges so formed serve to prime and select which cells will produce longer, high-current (and, therefore, high-brightness) discharges to the display anodes. The design is not limited to the 80-character/line display reported here; it can be extended to longer displays without the duty cycle or brightness being affected.     

Electron temperature in a.c. discharge excited between insulating electrodes †

The electron temperatures in a.c. discharges of frequency 50 c/s excited between plane parallel glass electrodes in air have been measured at various pressures. The electron temperatures have been computed by employing the Johnson—Malter double-probe technique. It is seen that the electron temperature increases from 8-5 × 10^{4 °} K to 12-8 7× 10^{4 °}K as the pressure is reduced from 10 Torr to 01 Torr. The nature of the variation of the electron temperature with pressure is seen to be similar to the corresponding variation in the case of d.c. discharges, as well as that in the case of audio frequency discharges between metal electrodes. This similarity indicates that, after the stable discharge is obtained, the discharge between the insulating electrodes is similar to that in the case of conducting electrodes.     

高对比度等离子体显示器驱动方法

提出了一种提高等离子体显示器(PDP)显示对比度的驱动方法，该方法以传统的寻址与显示分离(ADS)方式为基础，一场只需要一次全屏放电。在各子场的复位期，采用分别加在X和Y电极上的斜坡电压脉冲擦除壁电荷，斜坡电压脉冲末端的电位与X，Y电极在寻址期中被扫描到时所加电压一致，不仅提高了寻址的准确性，且有利于增大寻址电压动态范围并降低寻址电压。     

一种提高PDP亮度和对比度的新驱动波形

PDP由显示屏体和电路组成,电路驱动屏体,从而产生多彩的图像。介绍一种提高AC-PDP的对比度和亮度的驱动波形。在初始期,新的初始波形能提高对比度和分辨率,也能降低寻址电压。在维持期,新波形的脉冲可以减少自擦除放电,从而提高发光效率。接着提出对该驱动波形的进一步改进。最后给出了采用该驱动波形的42英寸PDP测得的实验结果,证实了这两种新波形的可行性。     

New addressing method using overlapping scan time of AC-PDP

A new plasma display panel driving method was proposed to reduce the address period. The scan time of the address method using overlapping scan time overlaps with the next scan time during the formative lag time of the discharge. Thus, without reducing the address pulsewidth and the scan pulsewidth, the driving method can reduce the address period. We could overlap the scan time of about 100 /spl sim/300 ns. However, the driving method has a narrow address voltage margin compared with a conventional method. In order to improve the address voltage margin of the driving method, the scan direction is set to the opposite direction compared with the conventional direction. As shown in experimental results, the address voltage margin of the new driving method is increased by 7/spl sim/10 V when the opposite scan direction is used.     

A new self-scanning method for producing high luminance in a DC gas-discharge bar-graph display panel

A new self-scanning method for use with a dc gas-discharge bar-graph display panel is described, enabling high luminance to be obtained. In this arrangement the cathode electrodes are connected to four busses and the anode electrodes to two busses. With the drive scheme used the luminance obtained is three times greater than that of conventional self-scanning bar-graph displays.     

New reset waveform for the contrast ratio improvement of AC-PDP

We propose a new reset waveform for the improvement of contrast ratio. A square pulse is applied to the address electrode while the reset pulse ramps and before the discharge between the sustain electrodes occurs. The square pulse induces a discharge between the address electrode and the X electrode, and the induced wall charge between the sustain electrodes is opposite to the applied ramping voltage between the sustain electrodes. Thus, the next discharge between the sustain electrodes becomes weaker. The weaker discharge during the reset period lowers background luminance and improves contrast ratio. The experimental results show that the contrast ratio can be improved by 35/spl sim/58% using this method compared with the conventional ramp reset method.     

Effects of pre-reset conditions on reset discharge from ramp reset waveforms in AC plasma display panel

The basic characteristics of reset discharges related to a wall voltage and a priming effect were investigated under a conventional ramp driving scheme. The reset discharges could be minimized by controlling the wall voltage which is determined by pre-reset conditions. Accordingly, the current study presents a simple pre-reset condition for minimizing the reset discharge. Essentially, it is not only to reduce the duration of reset discharges but also to reduce the intensity of light emissions when the wall voltage polarity is opposite to the external voltage polarity.     

OFDM系统中峰均比降低的次优化循环移位序列方法

部分传输序列（PTS）方法需遍历所有的可选相位因子,这样的计算量随分割子序列数按指数增长。本文在对循环移位PTS方法 (PTS/CSS) 和次优PTS方法 (sub-OPTS) 进行研究的基础上,提出了一种减少计算复杂度的次优化时域循环移位序列方法（sub-OPTS/CSS）。该方法用快速傅立叶变换（FFT）的时域循环移位特性增加更多备选信号;且仅对变换后的部分备选信号进行相位优化。同时,将其与已有的一些方法的备选信号、冗余比特数、运算量进行了分析和比较。理论分析和仿真结果表明,当使用相同的分割子序列数和相位旋转因子时,sub-OPTS/CSS方法降低PAPR的性能稍次于PTS/CSS方法,但搜索最佳相位时的计算量减少了一半;sub-OPTS/CSS方法降低PAPR的性能要优于sub-OPTS方法。      

The effect of fabrication parameters on a ridge Mach-Zehnder interferometric (MZI) modulator

A study of Mach-Zehnder interferometer (MZI) modulators using unetched and etched Ti:LiNbO/sub 3/ waveguides has been made. A full vectorial finite-element-based mode solver was used, followed by a finite element-based solution of the Laplace equation to calculate the electrooptic effect and, subsequently, the half-wave voltage, V/sub /spl pi// The optical loss due to the metal electrodes was also found using the H-field finite-element method (FEM) incorporating the perturbation method. The microwave effective index, n/sub m/, and the characteristic impedance of the metal electrodes, Z/sub c/, were also found for a number of electrode thicknesses and ridge heights. A semivectorial finite-element beam propagation method (SVFEBPM) was used to estimate the radiation loss for the curved input and output (I/O) waveguides of the MZI. The device characteristics were then studied by making changes to a number of fabrication parameters, of which the two most important were found to be the etch depth of the ridge and the thickness of the SiO/sub 2/ buffer layer.     

Optical and thermal properties of large-area OLED lightings with metallic grids

We investigate the effects of auxiliary metal electrodes on the optical and thermal properties of large-area (30 × 120 mm²) opaque and transparent white OLED lighting panels. Enlarging their emission area inevitably entails a non-uniform current distribution due to the limiting conductivity of transparent electrodes, causing local heat generation. To tackle it, we have used grid patterned Cr, Mo/Al/Mo, or Cu metal lines (0.15 mm in width) as auxiliary metal electrodes on an ITO anode. Among those, Cu metal grids exhibit the highest luminous efficacy with the least heat generation, and the most uniform light distribution by virtue of its lowest sheet resistance, followed by Mo/Al/Mo and then Cr metal grids. It is also found that local heat generation appears more seriously in large-area transparent OLED panels. With attempt to suppress it, we have also deposited Al metal lines (2 mm in width) on a semitransparent Al/Ag cathode by thermal evaporation, which brings in a highly uniform heat distribution. Furthermore, we study the effect of the shape of the light-emitting area on the luminance and heat distributions. A round-shaped OLED panel with a hexagonal metal grid exhibits highly homogeneous luminance and surface temperature distributions.     

The current injection method for AC plasma display panel (PDP) sustainer

A new concept of energy recovery for a plasma display panel (PDP) is proposed. Different from conventional LC resonant sustaining drivers, the current built up before inverting the polarity of the panel electrodes is utilized to change the panel polarity together with energy previously charged in panel capacitance. This operation provides zero-voltage switching of switches and reduction of electromagnetic interference by rejecting the surge current when the sustain switches are turned on. The buildup current helps to reduce the transition time of the panel polarity and may produce more stable light waveforms. This method is suitable for a PDP sustaining driver requiring stable light emission characteristic while it maintains low circuit loss like the series-resonant-type energy recovery circuit which is known to be a very effective method.