Direct electrical readout from plasma display/memory panels

A technique for extracting stored information from an array of plasma display/memory elements uses a direct electrical detection system that senses the charge flow in selectively excited elements. Electronic drive schemes based on this technique and suitable for realizing readout capability in a large-scale plasma display system are described. The design of specially configured sense amplifiers used in these systems, the nature of the noise signals encountered in these systems, and the results of reliability tests on a 128 × 128 line plasma display system with readout are discussed.     

A parallel self-shift technique for plasma display/memory panels

A technique for internally shifting information stored in a plasma-display/memory panel uses a discharge-related coupling phenomenon between neighboring elements together with a three-phase electronic drive scheme. Experimental results are reported which describe quantitatively the inter-element coupling phenomenon in some commercially available panels. An electronic drive scheme which uses this phenomenon to provide a four-directional self-shift display system is described. The effects of panel nonuniformity, the nature of the noise signals encountered in this system, and typical operating characteristics of this system are discussed.     

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.     

Recent developments in three-color plasma display panels

This paper describes recent developments in the fabrication of three-color-phosphor plasma display panels that improve both electrical and optical performance. The electro-optical characteristics of panels incorporating a phosphor bar pattern are presented, including the properties of panels fabricated with a black, UV-absorbing material surrounding the phosphors. In addition, processes developed to produce 20 × 20 in plasma panels with 512 × 512 three-color resolution elements at a total line density of 60 per inch are described.     

Aging characteristics of AC plasma display panels

The initial accelerated aging ("burn-in") and the subsequent alternate-line-aging (ALA) characteristics of the operating voltages of ac plasma display panels were studied for MgO films deposited on dielectric glass substrates at 25°-350°C in a residual gas pressure of 10^-6-10^-7torr. To study the effects of the presence of oxygen during film deposition, the films were also deposited in 10^-4-10^-5torr of oxygen. Films deposited at 350°C showed significantly better aging characteristics than those deposited in 25°C. This observed dependence of the aging characteristics on the various parameters of the panel-fabrication process is explained in terms of a postulated effect of oxygen on the surface properties of MgO films and the changes in the surface properties of the MgO films (caused by changes in the surface stoichiometry) produced by ion bombardment during the discharge.     

Thermal characteristics of glass-metal composition plasma display panels

Plasma display panels use gas plasma to produce light, with a technique very similar to that used for fluorescent tubes. This is currently the only flat panel technology available for very large flat-panel televisions. A newly developed plasma display panel utilizes a composition of glass, metal and frit glass sealing material, in addition to functional thin and thick film glass-powder-based laminate composites. This paper focuses on this new plasma display technology and discusses its structure and thermal reliability characteristics and challenges.     

等离子显示器用滤光膜的研制

等离子显示器(PDP)图像的颜色和亮度由经过调制的脉冲电流控制,该脉冲电流会产生电磁波、近红外线以及氖黄光干扰,影响其效果,需安装滤光膜。通过对不同种类、不同厚度的涂层进行对比研究,开发了一种PDP用滤光膜,其EMI屏蔽效能大于45 dB,比进口的略低,但透光率达到43%、高于进口值。氖黄光透光率为15%,近红外透光率低于10%,成本不到进口膜的1/3,完全可以取代进口产品,用于PDP显示面板。     

Surface aging mechanisms of AC plasma display panels

Excellent life performance is being achieved for ac plasma display panels through understanding of the causes of voltage changes, surface overcoat material research, and adjustment of the manufacturing process to eliminate contaminants. It has been found that surface aging phenomena are dominant in many practical cases. Because of prefereutial operation patterns (i.e., alpha numerics), a differential aging pattern may evolve. The differential pattern is the result of voltage changes which are different for heavily operated and lightly or nonoperated cells. It is shown that the nature and extent of surface changes are dependent on overcoat material selection and the presence (or absence) of contaminants introduced during manufacture. With the use of thin overcoat layers in contact with the gas, it is necessary to be aware of the possibility of surface film removal by sputtering. The effects of significant variables: gas pressure and composition surface material, and operating voltage are discussed.     

Optical memory readout by superluminescent diode with integrated photodetector

A superluminescent diode (s.l.d.) simultaneously operating as light source and light amplifier has been for the first time integrated monolithically with a photodetector. Experimental results are presented demonstrating the applicability of this device for optical memory readout.     

PDP荧光粉参数测量装置的研制

等离子平面显示(PDP)用荧光粉的主要参数有发射光谱,色坐标,激发光谱,相对亮度等。由于PDP荧光粉的激发光源在紫外 真空紫外波段,因此需要一套真空紫外激发 荧光光谱仪装置来测量这些参数。介绍了一种采用30W氘灯激发光源的PDP粉体测试装置。通过光路的聚焦式设计和高增益放大器的采用,实现了120～300nm波段,分辨率好于2nm的激发光谱测量。测试结果表明发射光谱和激发光谱的重复性好于±2%,色坐标误差小于±0.001。     

Self-shift plasma display panels with meander electrodes or meander channels

Two new types of self-shift plasma display panels with meander electrodes (ME-PDP's) and with meander channels (MC-PDP's) are described, both of which have new electrode configurations characterized by interdigital pairs of electrodes on each substrate. The panels have simple structures which do not require electrode crossovers, and therefore have good potentials for low cost compared with our former type of panel. Principles and characteristics of the two new types are discussed, and comparison between them leads to the conclusion that the ME-PDP, which can eliminate even the barrier structure by adopting meander electrode patterns, is superior for a high-resolution display.     

Write and erase waveforms for high-resolution AC plasma display panels

The successful operation of ac plasma display panels (PDP) depends on the optimization of panel parameters such as chamber gap, gas pressure, line width, and the use of half or full-select cancellation techniques. As resolution increases, however, so does the importance of the write and erase waveforms. A unique set of write and erase waveforms which are specifically designed to optimize the performance of high-resolution PDP's are discussed.     

Optical write-in for the plasma display panel

Techniques of changing the state of plasma display cells with externally applied light are presented. Optical write-in offers the advantage of high-speed parallel data transfer from a photographic transparency to a plasma display panel. It is established that light incident on a plasma cell causes a photoemission from the inner glass surface. The emitted electrons perturb the wall voltage and cause a change in state. The intensity of light needed to change the state of cells can be reduced, without changing the solid panel materials, by two techniques, Electron avalanches initiated by the photoelectrons can be used to decrease the light needed by a factor of 100. By flashing light during the plasma display cell gas discharge, the intensity of the light can be further reduced.     

Spatial distribution of wall charge density in AC plasma display panels

Experimental results are given for the spatial and temporal variation of both the wall charge density and the light intensity along the electrode lines of an ac plasma display panel. The results show that the major part of the luminous spreading is along the cathode line, and it does not accurately reflect the spreading of the wall charge. The wall charge density distribution is approximately symmetrical along both the cathode and anode lines, and it is fairly constant up to about a linewidth away from the edge of the electrode line. A qualitative explanation is proposed for this extended uniformity of the spatial profile of the density of wall charge.     

Multibit microwave memory readout from a ferrite-loaded stripline

Experimental multibit-microwave-memory-readout results obtained using direct-loaded and secondary-coupled toroidal ferrite memory elements in a strip transmission line are presented. Typical single-element readout response to a 4ns 650mA interrogation pulse was a bipolar 15ns ±21 mV signal using secondary coupling. The output-response magnitude decreases significantly as the number of memory elements loading the same stripline is increased.     

Secondary electron emission characteristics of dielectric materials in AC-operated plasma display panels

From the measurement of the ion-induced secondary electron emission yield γiit was shown that with increasing γiof the dielectric panel material the firing voltage of an ac gas discharge display panel decreased. The measurement of the energy distributflon of the secondary electrons showed that the dielectric material with higher γihas lower most-probable energy (MPE), and half-width (HW) values. The energy distribution introduced by Stolz in the ease of secondary electrons emitted from a metal was applied to the dielectric panel material and solved by using a computer. From this result, it was shown that the lower the electron affinity of the dielectric panel material, the higher is the γi. Under the condition when γibecame greater than unity, unstable self-sustained emission was observed even though the primary ion beam was cut off.     

A new sustainer by using clamping RC components for AC plasma display panels

A new sustain driver with an energy recovery circuit for ac plasma display panels is proposed. The proposed driver uses not expensive clamping diodes but relatively cheap RC components in the Y and X main boards without degrading the performance. Consequently, it features fewer power devices and lower cost because of no clamping diodes. To demonstrate the validity of the proposed driver, various experimental results with a prototype 42-inch HD PDP module are presented.     

Optimum composition of CaO, SrO dielectric materials in AC plasma display panels

The firing voltage Vfof ac operated plasma display panels can be reduced by coating the dielectric materials with (Ca, Sr)oxides. The reasons for the reduction of Vfare explained in this paper. The secondary electron emission yield, γi(Ar⁺), resulting from Ar ion bombardment, was directly measured for the compound oxides having various ratios of Ca to Sr. Also, the work function was obtained from the measurement of thermionic emission. The results show that γi(Ar⁺) reaches a maximum for a weight ratio of CaO to SrO of 1:3 while the work function reaches a minimum. From the results of Auger analysis and the measurement of optical absorption, it was confirmed that the most anion vacancies of SrO (F⁺s(H) color centers and F⁺scolor centers) were found in the sample of the preceding composition. (F⁺s(H) and F⁺scolor center are considered as a direct source of emission. As a result of the increase of (F⁺s(H) and F⁺scolor centers, reduction of the work function and increase of γi(Ar⁺) occur. The theoretical calculation of γi(Ar⁺), using the theory of Parilis et al., was carried out to clarify the influence of the work function upon γi(Ar⁺). The theoretical results are in good agreement with the measurement of γi(Ar⁺). From the discussion based on the potential ejection process in ae-plasma display panels, it is shown that the reduction mechanism of Vfis caused by the increase of F⁺scolor centers.     

一种低抖动噪声的PDP动态假轮廓改善方法

为降低等离子体显示器(PDP)动态假轮廓(DFC)改善中的抖动噪声,提出了一种抖动区域宽度自适应变化并融合孤立像素点分离的随机抖动改善DFC方法.首先分析DFC干扰条纹的特性,得到符合视觉特性的DFC评测方法;然后根据DFC的严重程度计箅相应的抖动区域宽度,采用融合孤立像素点分离的随机抖动方法实现未被选取的灰度级.仿真...     

Optical readout of resonant quartz sensors

A force-sensitive AT-cut quartz disc produced variable-frequency optical modulation with a depth of 8% at the 2 MHz fundamental resonance. The elements of a fibre-optic sensor were demonstrated, including optical powering of the oscillator and optical modulation at the difference frequency between a reference crystal and a sensor crystal.