• Title/Summary/Keyword: Address period discharge

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Gray Scale Plasma Display Panel with a New High-Speed Drive

  • Ryeom, Jeong-Duk
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.9
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    • pp.7-11
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    • 2007
  • The objective of this study is to evaluate the characteristics of a newly proposed high-speed drive method for the gray scale display for high-resolution plasma display panels(PDP). In the experiment it was found that the characteristics of gray scale display are not closely affected by a priming period below 50[${\mu}s$], the width of the priming period, and that it can be driven stably from the brightest sub-field to the darkest sub-field even though a priming discharge is applied to the 1 TV-field only once. Moreover, from the experimental result, the gray scale pattern of 8-bit and 9 sub-fields was stably displayed in the experimental PDP with scan pulses having the pulse width of 0.7[${\mu}s$]. An address voltage margin of about 25[V] and a sustain voltage margin of about 10[V] was obtained.

Measurement of Wall Voltage in Reset Discharge of AC PDP

  • Park, K.D.;Jung, Y.;Ryu, C.G.;Choi, J.H.;Kim, S.B.;Cho, T.S.;Oh, P.Y.;Jeon, S.H.;Choi, E.H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.722-725
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    • 2003
  • In AC plasma display, it is very important to quantify the wall voltage induced by the wall charge accumulated on the dielectric surface. If we know the quantities of the wall voltage in each period of every sequence; reset period, address period and sustain period, then it helps us to design the optimal driving waveform for high efficiency plasma display. We develop a new method to measure the wall voltage with VDS (Versatile Driving Simulator) system. From this method the wall voltage induced by a wall charge profiles just after the reset discharge of every cells in plasma display panel can be investigated and analyzed successfully. It is noted that the wall voltage profiles are influenced by the space charge and then they are stabilized as time goes by. It is also noted that both the remaining wall charge at the previous sequence and space charges contribute to wall voltage quantities just after the reset discharge. It is noted that the wall charges contribute dominantly after a few hundreds microseconds, while the space charges have been decayed within 100 ${\mu}s$ just after the reset discharge.

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3-Dimensional Emission characteristics of an AC PDP Cell

  • Jung, Jae-Chul;Jeong, Dong-Cheol;Bae, Hyun-Sook;Whang, Ki-Woong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.529-532
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    • 2004
  • The spatio-temporal variation of Infra Red(IR) emission images were obtained from a real 3-dimensional discharge space of a surface discharge type, alternating current plasma display panel(AC PDP) cell with the Ne-Xe(4%) 400Torr gas mixture. IR emissions were observed in each period of the ADS(Address and Display Separation) driving scheme with ramp initializing waveform using an images intensified charge coupled device(ICCD) camera. The roles of each electrode were identified and it was compared with the results of the discharge simulation and of the wall charge distributions measured by the electro-optic technique.

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Reduction of Ne Emission Using New Driving Scheme in AC-PDPs

  • Kim, Hyun;Jang, Sang-Hun;Tae, Heung-Sik;Chien, Sung-Il
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.65-68
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    • 2002
  • A new driving scheme is proposed to improve the color purity by reducing the neon (Ne) emission of 585 nm in an ac PDP. Applying the new driving scheme 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 9.2 % in comparison with a conventional case.

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Modified Ramp-Reset Waveform Robust for Variable Panel Temperature and its Discharge Characteristics

  • Jang, Soo-Kwang;Tae, Heung-Sik;Kim, Soon-Bae;Jung, Eun-Young;Suh, Kwang-Jong;Ahn, Jung-Chull;Heo, Eun-Gi;Lee, Byung-Hak;Lee, Kwang-Sik
    • Journal of Information Display
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    • v.7 no.1
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    • pp.25-29
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    • 2006
  • By the voltage threshold (Vt) close-curve measurement method, the changes in the discharge characteristics such as a firing voltage and IR emission among the three electrodes were examined relative to the low or high panel temperature ranging from -10 to $80^{\circ}$. The variation in the panel temperature was found significantly influence the surface discharge between the MgO surfaces rather than the plate gap discharge between the MgO and phosphor layers. Based on this experimental observation, a modified reset waveform that alleviates the surface discharge during a ramp-up and -down period was deeloped. By adopting the proposed reset waveform, a stable address discharge could be obtained irrespective of the panel temperature variation.

Transitional care for high-risk elderly patients pre/post discharge by collaboration between general hospital and community pharmacy: a pilot study

  • Park, Mi Seon;Lee, Ji Hee;Lee, Heung Bum;Kim, Ju Sin;Choi, Eun Joo
    • Korean Journal of Clinical Pharmacy
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    • v.32 no.1
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    • pp.27-36
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    • 2022
  • Background: Medication-related problems (MRPs) frequently occur during the discharge period. Elderly patients, particularly, are at high risk for these problems due to polypharmacy and the use of potentially inappropriate medications. The purpose of this study was to build and implement collaboration between general hospital and community pharmacies to address MRPs among high-risk elderly patients before/after discharge. Methods: This retrospective study was conducted between June and December of 2020. The inclusion criteria were patients with aged ≥65 years; residents of Jeonju; discharged from Jeonbuk National University hospital; either on medication of exceeding 10 medications (or high-risk medications) after hospitalization through the emergency room, or having severe illness. Patients received medication reconciliation and counselling by hospital pharmacists before discharge and home-visit pharmaceutical care as follow-up by community pharmacists after discharge. Results: Twenty-two patients agreed to home-visit pharmaceutical services. Fifteen and 11 patients completed the first and second home-visit pharmaceutical care service, respectively. Forty-two MRPs were identified in 15 patients. The types of high-frequency MRPs were incorrect administration of drug, adverse drug reactions, medication non-compliance, drug-drug interactions, lifestyle modifications, and expired medication disposal. After consultation with the pharmacist, 34 out of 42 MRPs were resolved. Conclusions: Transitional care for high-risk elderly patients before and after discharge was successfully built and implemented through a collaboration between general hospital and community pharmacies. This study suggests that home-visit pharmaceutical services may have positive effects on the safe use of drugs during the transition period; however, additional research is needed to expand on these findings.

Influence of Sustaining Frequency on the luminous Efficiency in AC-PDP (교류형 플라즈마 디스플레이에 있어서 유지방전 주파수에 따른 발광 효율에 미치는 영향)

  • 정의선;김대일
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.14 no.6
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    • pp.1-5
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    • 2000
  • Recently alternating-current Plasma Display Panel(AC-PDP) is in the spotlight as a digital television and high definition television. The panel structure widely adapted in commercial AC-PDP is three electrodes surface discharge type. At present time, the luminous efficiency is around 1lm/W, it should be a key factor for the commercialization. For the high luminous efficiency, the development of panel structure is necessary. At a given panel structure, a driving method should be optimized to get a sufficient luminous efficiency. The display image of AC-PDP could be realized by the repeated light emission from the discharge. Because most of discharge power is consumed in the sustaining period, the optimization of sustaining waveform is very important for the high luminous efficiency. ADS (Address and Display period Separated) driving method is commonly used. The average driving frequency of ADS driving method is ranged by several tens kilo of [kHz], however the actual frequency of sustaining period is in range of 100[kHz] to 200[kHz]. Based on this study, when the phosphor emits the visible light, it has a decay time of few milliseconds due to the material transfer to the phosphor to emit the visible light. Consequently the luminous efficiency decreases in proportion to the driving frequency. It is found that the luminous efficiency could be significantly improved by the low frequency sustaining driving method.

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Study on Sustain Driving Waveform for Linear Gray Scale Expression in AC Plasma Display Panel (플라즈마 디스플레이 패널에서 선형적 계조 표현을 위한 유지 구동파형의 연구)

  • Cho, Byung-Gwon
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.6
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    • pp.255-260
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    • 2014
  • A new sustain driving waveform and its implementation method is proposed to improve the gray scale linearity by applying the sustain waveform for producing the strong and weak discharge in AC plasma display panel. The driving method to express the gray scale of AC PDP is the combination of the several subfield in one TV frame, and the luminance of the each subfield is decided by the number of the sustain pulses. As the same amount of the strong plasma discharge is produced when the sustain pulses are applied during a sustain period, it looks easy to express the linear gray scale ideally. However, it is difficult to express the real linear gray scale due to the production of the address and first sustain discharge irrelevant to gray scale expression in every subfleld. Therefore, a new sustain driving waveformis adopted to produce partially the weak discharge instead of the strong discharge by the modification of the sustain pulses shape during the sustain period and the gray scale expression is close to the linearity.

Dynamic Voltage Margin of AC PDP with the Narrow Erase Pulse Method (세폭소거 펄스 방식을 적용한 AC PDP에서의 동특성 전압 마진)

  • An, Yang-Ki;Yoon, Dong-Han
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.51 no.11
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    • pp.541-545
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    • 2002
  • This paper proposes the new narrow erase method to erase wall charges formed in an AC plasma display panel (PDP) cell. In the proposed method, pulse timing of switch at the sustain period is adjusted for inducing, a weak discharge. Then, after the narrow erase, the voltage of the X electrode is set to differ from that of the Y electrode. For the proposed method, the measured maximum address voltage margin was 38.3V at Y_Rest voltage of 100V and sustain voltage of 180${\sim}$185V. However, for the conventional method, in which the X and Y electrodes are set to be of equal voltage after the narrow erase, the measured maximum address voltage margin was 31.3V at Y_Rest voltage of 150V and sustain voltage of 180V. This result shows that the measured maximum voltage margin for the proposed method is about 7V(22%) higher than that for the conventional method.

New Selective Reset Waveform for a Large-Sustain-Gap Structure in AC PDPs (AC PDP의 장방전 구조의 구동을 위한 새로운 셀렉티브 리셋파형)

  • Song, Tae-Yong;Kim, Dong-Hun;Kim, Won-Jae;Lee, Seok-Hyun
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.1391-1392
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    • 2007
  • A selective reset waveform which can improve the dark room contrast ratio in a large sustain gap structure is suggested in this paper. When conventional selective reset discharge is performed, frequent unexpected misfiring happens because of high Vxb and much quantity of negative wall charge formed on Y electrode during final sustain period. The misfiring between sustain electrode and address electrode can be removed by lowering Vxb value and the misfiring between address electrode and scan electrode can be prevented by applying last sustain pulse of 40us and rectangular pulse of Vscan on Y electrode. When the selective reset waveform has one time reset per 8 subfields, black luminance of 1.55 cd/m2 can be obtained without any misfiring.

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