Plasma Display Panel Research Articles

Effects of RF-Plasma Pretreatment on Panel-Aging Characteristics in AC Plasma Display Panel with Full-HD Cell Size

The organic impurities, such as CxHy, on the MgO surface are known to be an important parameter that affects the panel-aging characteristics in an ac plasma display panel (PDP). Accordingly, the RF-plasma pretreatment on the MgO layer is adopted to reduce the panel-aging process time by reducing the organic impurities. The resultant changes in the discharge characteristics during the panel-aging process, including the firing voltage, formative address delay time, statistical address delay time, and wall voltage variation, were examined in comparison with both cases with and without plasma pretreatment on MgO layer using various gases in the 50-in. full-high definition ac-PDP with He (35%) - Xe (11%) contents. It is concluded that the Ar or Ar followed by O2 plasma pretreatment was the most effective in eliminating the residual impurities on the MgO surface, thereby reducing the panel-aging process time.

Reduction of Permanent Image Sticking in AC Plasma Display Panel Using Negative Sustain Waveform

The permanent image sticking phenomena were examined and compared for the two different sustain driving waveforms such as the positive and negative sustain waveforms. To compare the permanent image sticking phenomena for both waveforms, the differences in the display luminance, chromaticity coordinate, color temperature, infrared emission, and discharge current were measured in the image sticking and non-image sticking cells. It was observed that the negative sustain waveform contributed to mitigating the permanent image sticking in comparison with the positive sustain waveform. 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 Vt closed curve, atomic force microscope, and photoluminescence analyses.

Uniform Phosphor Spheres of Diverse Emission Colours via Homogeneous Precipitation

Basic carbonate monospheres of various lanthanide combinations are successfully synthesized by the urea-based homogeneous precipitation technique, which are then converted into well dispersed phosphor particles that emit diverse colours. Sequential precipitation is commonly observed for these mixed cation systems, calling for adequate annealing of the basic carbonate precursors to attain cation homogenization in the final oxide particles and thus better luminescence, through eliminating localized concentration quenching of luminescence. It is shown that, owing to their excellent dispersion and uniform size, the phosphor spheres are readily assembled into close-packed luminescent films, allowing their wide applications in white LEDs, plasma display panels (PDPs), and field emission displays (FEDs).

One step synthesis and X-ray induced luminescence in RGB PDP phosphors

One step combustion synthesis of preparation of plasma display panel (PDP) phosphors for X-ray induced luminescence is reported. The prepared phosphors were characterized by XRD, PL and X-ray excited luminescence (XEL) techniques. Phosphors emitting three primary colors have been be prepared by using the combustion synthesis. These may be used for X-ray imaging phosphors.

Images of Striations in Large-Gap Plasma Display Panels

Striations in large-gap coplanar dielectric barrier discharge (DBD) are investigated both experimentally and theoretically. We show the striations in a large-gap coplanar DBD. The time-resolved images of discharge were obtained by macrocell experiment and PIC-MCC simulation. Two series of striations appear in the cell during the discharge developing between the faced electrodes and the coplanar electrodes. The simulation is in accordance with the stratified potential in the space.

Biased scan of plasma display panel for data voltage reduction

This paper proposes a method of reducing the data voltage Vd of plasma display panels (PDPs). The proposed biased-scan method uses two separate ground systems: one for the sustain pulse generator (FGND) and the other for the data address and control systems (CHGND). A dc voltage bias, which is applied between CHGND and FGND during the address period, reduces Vd while preventing the undesired glow discharge induced by a scan pulse only. CHGND is connected to FGND for the first sustain pulse of each subfield, which reduces the time lag of address discharge, but it is separated from FGND for the other sustain pulses to increase the margin of the sustain voltage. The proposed method was tested on a 15% Xe 50-in. Full HD (1920×1080) single-scan PDP which had a sustain discharge gap of 110μm. Vd could be reduced by 20V (30%), and the power consumption of the Vd voltage source decreased by ∼25W (50%) from that of the conventional method.

The role of a diffusion barrier in plasma display panel with the high gamma cathode layer

Plasma display panel (PDP) with MgO-SrO double cathode layer and SiO2 diffusion barrier is proposed to make the SrO layer free of contaminations. Time of flight-secondary ion mass spectrometry (TOF-SIMS) analysis shows the diffusion of impurities, like Na and K, can be effectively blocked while a new SrO layer is formed on top of the MgO layer. This structure shows that high Xe gases can be used to improve the luminous efficacy 2.3 times and decrease the voltage margin more than 10 V compared to the conventional PDP using Ne-Xe 15%. The aging time was also significantly decreased to 3–4 h.

Control System of PDP Lighting Inspection Machine

The test of panel’s display effect is a key step in the panel production. Lighting inspection machines test the electrical, optical and surface information of Plasma Display Panels (PDPs). This machine is based on a PLC control system and a color analysis system. The PLC system controls a visual positioning system and links to Manufacturing Execution System (MES) and a panel conveyor. This paper considers the structure design and action workflow of the lighting inspection machine. Multi-layer network is built to connect with the whole production system. Optional operation modes are designed in control program and Man-machine interface is introduced to facilitate the operation.

Dual Surface Discharge Mode for Improving Luminous Efficacy in AC Plasma Display Panel

Dual Surface Discharge Mode for Improving Luminous Efficacy in AC Plasma Display Panel

Dual Surface Discharge Mode for Improving Luminous Efficacy in AC Plasma Display Panel

In the current paper, we propose a new sustain waveform for dual light emission to improve the luminous efficiency of ac-plasma display panels (ac-PDPs). The proposed sustain waveform featuring dual discharge per sustain pulse has two rising steps, thus producing a second large discharge using the first small discharge generated in the first rising step. The resultant longer-sustained discharge can reduce power consumption without sacrificing luminance, thereby improving luminance efficiency by about 20%. Furthermore, the side ICCD image analysis reveals that owing to positive wall charges accumulating on the phosphor layer during the first small discharge, the ion incidence onto the phosphor layer can be suppressed during the second large discharge, thereby minimizing phosphor degradation during sustain discharge.

A Novel Single-Stage AC-DC Converter to Supply Sustain Power for Plasma Display Panels

This paper presents a new single-stage ac-dc converter to supply sustain power for the plasma display panel (PDP). A new bridgeless single-stage ac-dc converter is proposed for a high efficiency sustain power supply. The proposed converter integrates the power factor correction (PFC) circuit with the isolated dc-dc converter. It provides the sustain voltage from the ac line without using any full-bridge diode rectifier. Conduction losses are lowered by eliminating the full-bridge diode rectifier. Switching losses are reduced by zero-voltage switching (ZVS) of the power switches and zero-current switching (ZCS) of the power diode. By simplifying the circuit structure and reducing power losses, the cost and power consumption of the PDP is improved. The proposed converter is theoretically analyzed in detail. Experimental results based on a 180 W (200 V/0.9 A) prototype circuit are discussed to verify the performance of the proposed converter for 37-in PDP displays.

Modified Reset Waveform for High Speed Address under High Ambient Temperature in AC Plasma Display Panel

Achieving a stable and fast address discharge under a high ambient temperature depends strongly on how constant the wall voltage formed through the reset discharge remains throughout the address period. It was observed that the wall voltage after the reset period varied considerably under a high ambient temperature, thereby aggravating a stable address discharge, mainly due to an increase in the formative discharge delay. Thus, based on the fact that the wall voltage variation during an address period is directly related to the emission of exo-electrons from the MgO surface, it was anticipated that forcing the emission of the exo-electrons prior to the address period would minimize the wall voltage variation during the address period. As a result, the proposed reset waveform with the ramp-up holding part optimized according to the subfield conditions was able to minimize the wall voltage variation during the address period, achieving a fast and stable address discharge under a high ambient temperature of +65 °C in a 50-in. AC plasma display panel (PDP) with full high-definition (HD) resolution.

Discharge Luminescence Characteristics of Ultrahigh-Resolution Plasma Display Panels with a 0.3-mm Pixel Pitch

We experimentally investigated the effect of increased generation efficiency of excited Xe atoms on ultrahigh-resolution plasma display panels (PDPs). At a horizontal cell pitch of 0.1 mm, the sustain voltage increased; however, the generation efficiency was equal to or higher than that obtained at the conventional 0.22-mm cell pitch. We investigated the luminous efficiency of fine-pitch discharge cells, which are fabricated with fine-grain colour phosphors. The absolute luminous efficiency of the experimental fine pitch panel is estimated to be 0.68 lm/W.

Modified Reset Waveform for High Speed Address under High Ambient Temperature in AC Plasma Display Panel

Modified Reset Waveform for High Speed Address under High Ambient Temperature in AC Plasma Display Panel

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.

Mechanism of high luminous efficacy in plasma display panel with high secondary electron emission coefficient cathode material analyzed through three-dimensional fluid model simulation

The mechanism to realize high luminous efficacy in a plasma display panel fabricated with a cathode material possessing a high secondary electron emission coefficient (γ) for Ne and Xe ions was studied via three-dimensional numerical simulation. When a high γ cathode material is used, the increased electron heating efficacy is responsible for increasing vacuum ultraviolet (VUV) efficacy with 10% Xe content gas. However, the continued availability of sufficient secondary electrons during the dynamic moving phase of the cathode sheath in which the electric field remains weakened causes increasing VUV efficacy with 30% Xe content gas. It was found that the improvement of the luminous efficacy of the plasma display panel with a high γ cathode material is maximized under the condition of high Xe content gas because of the simultaneous increase of the electron heating efficacy and Xe excitation efficacy.

An Experimental Observation on the Effect of Oxygen and Nitrogen Gas Addition on the Image Retention in an AC Plasma Display Panel

In this paper, the effect of oxygen and nitrogen gas addition to the Ne-Xe mixture discharge gas on the various kinds of image retention was investigated in 42-inch AC Plasma Display Panels. The image retentions were dramatically relieved with a small amount of molecular gas addition. It was observed that the temporal variation of the reset threshold voltage induced by discharge heat-run can be suppressed by adding a small amount of molecular gases to the discharge gas. Both residual gas and cathodoluminescence analyzes showed that the added molecular gases could be incorporated in MgO surface during the discharge. With the investigation on the feasibility, we suggest that a small amount of nitrogen gas addition is suitable for the relief of image retentions which can be adapted in industry.

The phase discharge and luminescence area characteristics of La0.5Sr0.5CoO3 as a cathode

AbstractLa0.5Sr0.5CoO3 was used as a cathode for the first time when a plasma display panel was used on a handheld personal computer. It has favorable sputtering resistance characteristics and stable discharge characteristics in gases. A cathode made of La0.5Sr0.5CoO3 has unique electrical characteristics in early phase discharge voltage and luminescence characteristics. The discharge voltage and luminance continue to decrease from the starting value. The discharge and luminescence area shift of the La0.5Sr0.5CoO3 were investigated by analysis of a DC plasma panel fabricated as a prototype. It is assumed that the shift in the discharge voltage and luminance are caused by a shift in the discharge and luminance area of the cathode surface, and that the shift of the current density is caused by the surface profile of the cathode particles. In order to elucidate this mechanism, a spherical model was applied to the discharge voltage shift, and the shift of the discharge voltage and luminance was simulated by applying this model to the measured values. © 2011 Wiley Periodicals, Inc. Electron Comm Jpn, 94(8): 12–18, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10353

The effect of electrode tilt angle on the characteristics of coplanar dielectric barrier discharges with Xe-Ne mixtures

The results of a two-dimensional fluid simulation of a plasma display panel (PDP) cell show that the discharge characteristics of a coplanar dielectric barrier discharge can be controlled by the electrode tilt angle rather than by the gas mixture ratio or gap distance. The change in the tilt angle results in a significant change in the wall charge distribution and the discharge duration for each pulse. Therefore, the breakdown voltage, plasma density, light brightness, and luminous efficacy can be controlled by the tilt angle. A concave electrode structure allows large wall charge accumulation near the outer edge of two coplanar electrodes, and it results in a long-duration discharge, high luminance, and high luminous efficacy. On the other hand, a convex electrode structure allows high wall charge accumulation near the gap between two coplanar electrodes, and it results in a short-duration discharge with a decreased breakdown voltage.

Simulation studies of the dielectric layer effect on the discharge characteristics of the shadow mask plasma display panel

The shadow mask plasma display panel, developed from the alternating current matrix plasma display panel, possesses several interesting features such as a simple manufacturing process, low cost, and short response time. The discharge process in cells with different dielectric layer thicknesses and relative permittivities at the same driving voltage was simulated based on a particle-in-cell/Monte Carlo collision model. It was found that the discharge characteristics were improved with an increase in the relative permittivity and a reduction in the dielectric layer thickness. The mechanism used in this phenomenon was analyzed theoretically and verified further by simulation, using different driving voltages. The results imply that the luminous efficacy can be improved either by reducing the relative permittivity or by increasing the thickness of the dielectric layer.