• Title/Summary/Keyword: pulse driving

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Gate Driving Methods to Compensate Feed-Through Voltage for Large Size, High Quality TFT-LCD (대면적 고화질 TFT-LCD의 Feed-through 전압 보상을 위한 Gate Driving 방법)

  • 정순신;윤영준;박재우;최종선
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.99-102
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    • 1999
  • In recent years, attempts have been made to greatly improve the display quality of active-matrix liquid crystal display devices, and many techniques have been proposed to solve such problems as gate signal delay, feed-through voltage and image sticking. To improve these problems which are caused by the fried-through voltage, we have evaluated new driving methods to reduce the fled-through voltage. Two level gate-pulse was used for the gate driving of the cst-on-common structure pixels. And two-gate line driving methods with the optimized gate signals were applied for the cst-on-gate structure pixels. These gate driving methods were better feed-through characteristics than conventional simple gate pulse. The evaluation of the suggested driving methods were performed by using a TFT-LCD array simulator PDAST which can simulate the gate, data and pixel voltages of a certain pixel at any time and at any location on a TFT array. The effect of the new driving method was effectively analyzed.

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A Study on the Drowsy Driving Prevention System using the Pulse Sensor (맥박센서를 이용한 졸음방지운전시스템에 관한 연구)

  • Park, Chun-Myoung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2016.05a
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    • pp.577-578
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    • 2016
  • This paper presents a method of vehicle safety system using a pulse sensor which will be able to occurs drowsy driving accident when people driving. The proposed vehicle safety system alarms according to the driver drowsy condition, therefore the driver prevent the direct and $2^{nd}$ accident beforehand cognitive unexpected and dangerous accident using vehicle safety system.

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Optimized Gate Driving to Compensate Feed-through Voltage for $C_{ST}-on-Common$

  • Jung, Soon-Shin;Yun, Young-Jun;Park, Jae-Woo;Roh, Won-Yeol;Choi, Jong-Sun
    • 한국정보디스플레이학회:학술대회논문집
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    • 2000.01a
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    • pp.73-74
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    • 2000
  • In recent years, attempts have been made to greatly improve the display quality of active-matrix liquid crystal display devices, and many techniques have been proposed to solve such problems as gate signal delay, feed-through voltage and image sticking[1-3]. To improve these problems which are caused by the feed-through voltage, we have evaluated new driving methods to reduce the feed-through voltage. Two level gate-pulse was used for the gate driving of the cst-on-common structure pixels. These gate driving methods offer better feed-through characteristics than conventional simple gate pulse. Optimized step signal will compensate by step pulse time and voltage. The evaluation of the suggested driving methods were performed by using a TFT-LCD array simulator PDAST which can simulate the gate, data and pixel voltages of a certain pixel at any time and at any location on a TFT array. The effect of the new driving method was effectively analyzed.

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Influence of Sustain Pulse-width on Electrical Characteristics and Luminous Efficiency in Surface Discharge of AC-PDP

  • Jeong, Yong-Whan;Jeoung, Jin-Man;Choi, Eun-Ha
    • Transactions on Electrical and Electronic Materials
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    • v.6 no.6
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    • pp.276-279
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    • 2005
  • Influences of sustain pulse-width on electrical characteristics and luminous efficiency are experimentally investigated for surface discharge of AC-PDP. A square pulse with variable duty ratio and fixed rising time of 300 ns has been used in the experiment. It is found that the memory coefficient is significantly increased at the critical pulse-width. And the wall charges and wall voltages as well as capacitances are experimentally measured by Q- V analysis method along with the voltage margin relation, in terms of the sustain pulse-width in the range of $1{\mu}s$ to $5{\mu}s$ under driving frequency of 10 kHz to 180 kHz. And the luminous efficiency is also experimentally investigated in above range of sustain pulse-width with driving frequency of 10 kHz to 180 kHz. It is noted that the luminous efficiency for 10 kHz and 180 kHz are 1.29 1m/W and 0.68 1m/W respectively, since the power consumption for 10 kHz is much less than that for 180 kHz. It has been concluded that the optimal sustain pulse-width is in the range of $2.5 {\~}4.5{\mu}s$ under driving frequency range of 10 kHz and 60 kHz, and in the range of $1.5 {\~} 2.5{\mu}s$ under driving frequency range of 120 kHz and 180 kHz based on observation of memory coefficient, and wall voltage as well as luminous efficiency.

New Driving Method for Fast Addressing of AC-Plasma Display Panel

  • Kim, Gun-Su;Choi, Hoon-Young;Lee, Seok-Hyun;Seo, Jeong-Hyun
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.726-729
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    • 2003
  • A new driving method is proposed to reduce the address period. The scan time of new driving method overlaps with the next scan time during the discharge lag time. Thus, without reducing the address pulse width and the scan pulse width, the new addressing method can reduce the address period. The results show that the scan time of about 100ns ${\sim}$ 300ns can be overlapped without the misfiring,.

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Driving and Position Sensing Algorithm for an Electrostatic Actuator Using Pulse-width Modulation (펄스폭 변조를 이용한 정전형 액추에이터의 구동 및 위치 검출 알고리즘)

  • Min, Dong-Ki;Jeon, Jong-Up
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.17 no.3
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    • pp.65-70
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    • 2008
  • Capacitive position sensing with modulation technique is widely used in electrostatic actuator applications. To maximize the electrostatic force and the position-sensing gain, capacitors for driving and capacitors for sensing are shared, i.e, after applying the driving voltage with high-frequency modulating signals using op amps, the position is demodulated from the modulated signal. In high-voltage applications, however, low bandwidth of a high-voltage op amp hinders adding the high-frequency modulating signal to the driving voltage. In this paper, new and very simple driving and sensing method is proposed, in which the pulse-width modulated driving voltage eliminates the need of the high-frequency modulating signal for position sensing. This new algorithm is proved by the simulation results using Matlab/SIMULINK.

Performance Evaluation of 2-Dimensional Light Source using Mercury-free Flat Fluorescent Lamps for LCD Backlight Applications

  • Park, Joung-Hu;Cho, Bo-Hyung;Lee, Ju-Kwang;Whang, Ki-Woong
    • Journal of Power Electronics
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    • v.9 no.2
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    • pp.164-172
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    • 2009
  • Recently, 2-dimensional flat light sources have been attracting much attention for its use in LCD backlight applications because of its high luminous efficiency and uniformity. A long-gap discharge, mercury-tree flat fluorescent lamp has been developed, which shows a high brightness ($>5000\;cd/m^2$) and high luminous efficacy (60 lm/W). Additionally, it has a wide operating margin and stable driving condition with the aid of an auxiliary electrode. For driving the lamp, a narrow pulse power to maintain the glow discharge state is required. Since there has been no research for this kind of lamp driving, this paper proposes a newly developed short-pulse, high-voltage lamp-driving scheme. The proposed lamp system uses a ballast with a coupled-inductor in order to raise the short pulse voltage up to the lamp ignition level and to obtain energy-recovery action during the glow discharge mode. The operation principles are presented and also the system performances such as the lighting efficiency, spatial and angular uniformities are evaluated by hardware experiments. The results show that the proposed lighting system is a good candidate for the next-generation of LCD backlight systems.

Improved Waveform during the Addressing Period for the Improvement of the Addressing Time for AC PDPs

  • Lim, Jong-Sik;Kim, Hyun-Seok;Kim, Joon-Yub
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.511-514
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    • 2004
  • ADS(Address Display period Separation) driving method has been considered to be the most appropriate driving technique for AC PDPs. However when the ADS driving method is applied to the high-resolution AC PDP, the required long addressing time often becomes a problem. In this paper, we present a new waveform for reducing the addressing time and for the stable addressing discharge. In this new waveform, a wall charge acceleration pulse is applied to the common electrode right after 80us scan time. In this way, the charge generated by the addressing discharge is accelerated to the electrodes. Experiments using the wall charge acceleration pulse showed that we could stably address an AC PDP with the scan pulses having pulse width of 1 us

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Driving Method of Ultraviolet Sensor for Fire alarms using Pulse Width Modulation (PWM을 이용한 화재 감지를 위한 자외선 센서의 구동 방법)

  • Lim, Byung-Hyun;Ko, Nak-Yong;Hwang, Jong-Sun;Kim, Yeong-Min
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.05c
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    • pp.31-35
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    • 2004
  • We propose driving method of Ultraviolet sensor for fire alarms using pulse width modulation that used to fire detector with sensor of private-use detectable light energy as ultraviolet in energy of electromagnetic-wave type radiate from flame, when combustible burn with contain carbon,. Ultraviolet sensor is UV Tron using gas multiplication effect to current discharge and photoelectric effect of metal. To have high sensibility and to gain proper output voltage, it has high responsive performance. This research designed driving circuit with UV sensors and proposed method of false alarm reduced to resemble fire. the result propers the prevention and extinction of fire technique degree, certificated operation of detector.

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Design of a CMOS On-chip Driver Circuit for Active Matrix Polymer Electroluminescent Displays

  • Lee, Cheon-An;Woo, Dong-Soo;Kwon, Hyuck-In;Yoon, Yong-Jin;Lee, Jong-Duk;Park, Byung-Gook
    • Journal of Information Display
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    • v.3 no.2
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    • pp.1-5
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    • 2002
  • A CMOS driving circuit for active matrix type polymer electroluminescent displays was designed to develop an on-chip microdisplay on the single crystal silicon wafer substrate. The driving circuit is a conventional structure that is composed of the row, column and pixel driving parts. 256 gray scales were implemented using pulse amplitude modulation method. The 2-transistor driving scheme was adopted for the pixel driving part. The layout was carried out considering the compatibility with the standard CMOS process. Judging from the layout of the driving circuit, it turns that it is possible to implement a high-resolution display about 400 ppi resolution. Through the HSPICE simulation, it was verified that this circuit is capable of driving a VGA signal mode display and implementing 256 gray levels.