• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.38-41
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• 2009

We demonstrate a new commercial green phosphorescent organic light emitting device (OLED) in a bottom emission device and top emission microcavity. The bottom and top emitting phosphorescent OLEDs (PHOLED$^{TM}$s) had luminance efficiencies of 60cd/A and 137cd/A respectively, at a luminance of 1,000cd/$m^2$. The top emission microcavity was close to 1953 NTSC color requirements with 1931 CIE color coordinates of 0.231, 0.718. A record green PHOLED lifetime of >3,500hrs to LT95 from 4000cd/$m^2$ is demonstrated for the microcavity device.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.5
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• pp.382-388
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• 2016

When Flat Panel Display (FPD) is made with backlight module, such as LED TV, it inherently suffers from the non-uniform backlight luminance problem that results in un-even brightness distribution throughout the TV screen. If the luminance of each pixel location of a TV screen as a function of the driving voltage can be measured, it can be used to compensate the non-uniformity of the backlight module. We use a carefully calibrated imaging system to take pictures of a TV screen at different levels of brightness and generate the compensation functions for the driving circuitry to correct the luminance level at each pixel location. Making use of the fact that the luminance of the screen is normally brightest at around the center of the screen and gradually decreases toward the border of the screen, the luminance of the whole TV screen is approximated by a mathematical function of the pixel locations. The parameters of the function are computed in the least square sense by the values of both the pixel luminance sent from the driving circuit and the grayscale value measured from the image taken by the imaging system. To justify the correction system, a simple second order polynomial function is used to approximate the luminance across the screen. When the driving circuit voltage is corrected according to the measured function, the variance of the screen luminance is reduced to one tenth of the one measured from the un-corrected TV screen.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.53-56
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• 2002

Samsung's newly developed high luminance efficiency 42" VGA plasma display panel is introduced. A new discharge cell structure, SDR (Segmented electrode in Delta color arrayed Rectangular subpixel) has been applied to a full size panel for the first time. In this paper, we describe how this new discharge cell structure for high efficiency is integrated to an energy saving plasma display with better picture quality.

• Journal of Information Display
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• v.9 no.4
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• pp.39-44
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• 2008

This paper investigates the effects of the existing sealing methods, such as the conventional atmospheric-pressure sealing method and vacuum sealing, on temporal bright-image sticking. To produce a residual image caused by temporal brightimage sticking, the entire region of a 42-in panel with an Xe-(11%)-He(35%) gas mixture was abruptly changed to a full-white background image after displaying a square-type image at peak luminance for about 60s. From the monitoring of the difference in the display luminance, infrared emission, color temperature, and disappearing time between the cells with and without temporal bright-image sticking, it was observed that the vacuum sealing method contributes to the reduction of temporal bright-image sticking.

• Journal of the Optical Society of Korea
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• v.16 no.2
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• pp.145-150
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• 2012

We present a display-based visual stimulator for psychophysical and electrophysiological visual sensitivity measurements. The stimulator offers various psychophysical visual stimuli and transfers the signals from external devices along with the stimulation signals to an electrophysiological recorder. As an experimental demonstration, we perform a visual sensitivity experiment in the mesopic vision range by using the display-based stimulator. The intensity of the steady-state visual evoked potential is observed to correlate with the luminance of the flickering visual stimulation. For the psychophysically determined detection thresholds, we determine the mesopic luminance, showing agreement with the perceived brightness within the uncertainty of the luminance measurement.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.520-524
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• 1999

Light-emitting diode(LEDs), diode arrays, and phosphor display panels are finding increased use in a variety of commercial applications. Present and anticipated application of these devices include solid state indicator and display systems. In this work, Phosphor based on ZnS:Cu are used. Relation by luminance with the thickness of insulating layer and phosphor layer are discussed. Increased thickness of insulating layer are stable on voltage to 300V. By considering thickness and voltage, optimal structure and thickness are investigated. In order to maximize even surface emission, various sieving processes are introduced. 150cd/m$^2$ luminance by various wave intensity are investigated in stable voltage and frequency.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.171-175
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• 2004

Need of a dimmer function becomes more important with increasing interest on a HDTV for home theater applications. In a conventional ac PDP, a possible method to reduce luminance of a whole panel is to reduce a total number of sustain pulses and then to change the gray level. However, the reduction of the total sustain number causes the step of luminance to be rough Moreover, it is impossible to control the luminance of the panel for a given gray level. In this paper, a simple and robust method is proposed to control linearly the luminance of whole panel by applying the asymmetric sustain pulses in the display period of the ADS driving scheme. As the range of luminance control by the proposed method is about 50% for a given gray level. Moreover, it is experimentally verified that the proposed method shows similar dynamic margin performances compare with the conventional method.

• Journal of the Korea Safety Management & Science
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• v.10 no.3
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• pp.73-79
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• 2008

Display's life time is defined as the time of 50% luminance drop. It was used luminance and temperature as accelerated factor to accelerated lifetime at test. When it's working jule-heat is generated and device's temperature is growing as any temperature because OLED is self-luminance display device. So we decided temperature condition is 25, $70^{\circ}C$, and luminance condition is $60{\sim}300cd/m^2$ in test. It's assumed accelerated lifetime model by result of the test.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.329-332
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• 2003

The effects of an auxiliary address pulse driving scheme, in which an auxiliary short pulse was applied to the address electrode during a sustain-period, was examined under the various image patterns of the 42-inch WVGA ac-PDP. When the auxiliary address pulse driving scheme was applied, the luminance of the red, green and blue cells were measured respectively. The luminance, luminous efficiency and current were measured under the full-white pattern of the 42-inch ac-PDP. As a result, the luminance of blue cell was improved approximately by 17 %, whereas the luminous efficiency of the full-white pattern was improved approximately by 34 % without a misfiring discharge in comparison with conventional driving scheme.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.52 no.2
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• pp.61-67
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• 2003

To improve the luminance and luminous efficiency of a surface-discharge alternate current plasma display panel, we analyzed the sustain discharge characteristics as the voltage of the address electrode In the study. As the results, when the address voltage is a half of the sustain voltage in the sustain period, the luminance and luminance efficiency are the highest. The luminance efficiency increased about 16.2%~20.8% compared with the conventional type.