• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.947-950
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• 2008

This paper reports of traceable and repeatable time resolved colorimetric measurements of the luminance- and colour variation occurring during the frame refresh period of FPD's. During one frame period a number of measurements are performed, and for the dynamic artifacts a simulated smooth pursuit eye tracking algorithm is included.

• KIEAE Journal
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• v.9 no.6
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• pp.65-72
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• 2009

Lighting for outdoor advertising is very common feature of building facades as they provide the information and commercial identification. As the interest of improving street beautification more widely, application of various lighting technologies has been develop for advertisement such as electric sign board and signage. Furthermore, the installation of higher sign luminance than needed has many negative consequences, including higher energy consumption and light pollution. There are now no standard for outdoor advertisements in terms of luminance, and installation of indiscreet outdoor advertisement without luminance consideration is becoming more commonplace. This study was to evaluate the luminous characteristics of outdoor advertising as a function of sign and building facade luminance, luminance ratio. Data were collected on 8 electric sign boards, 20 internally illuminated, externally illuminated, neon, and channel letter signs and 4 commercial areas. Photometric measurements were taken by CS-100(Minolta) and ProMetric-1400(Radiant Imaging) for various sign modes and sign design. Also luminance of building facades were analyzed according with CIE standard of maximum obtrusive light permitted for exterior lighting installations. The findings are as follows; (1) There were excessive luminance of electric sign boards that could affect adjacent building facade and night sky luminance. (2) Sings that are externally illuminated providing an inappropriate amount of light on to the outer surface of the sign caused higher building facade luminance and potential of unnecessary glare.

• 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.

• Journal of Information Display
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• v.8 no.2
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• pp.25-31
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• 2007

MgO thick film for ac-PDPs was formed via electrophoresis deposition process and its effect on luminance and luminance efficiency were evaluated. The electrophoresis deposition process of MgO thick film was optimized through parametric study and defects levels in MgO powders was evaluated using cathodoluminescence spectra measurements. The results demonstrate a possibility of using MgO thick film as electron emission layer for ac-PDPs.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.171-174
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• 2005

Experimental measurements are reported and compared with the results of a two-dimensional fluid simulation for the investigation of the discharge characteristics regarding the change of the mixture ratio of Ne-Xe-He noble gases. The increase of Xe contents results in the increases of luminance and luminous efficiency while it also results in the increase of the breakdown voltage and the discharge time lag. The addition of He gas increases the brightness and the luminance efficiency. When Xe partial pressure is low, the luminance efficiency increases with the amount of He at the same total pressure. When Xe partial pressure is high, however, the luminance efficiency has a maximum value when the partial pressure of He is about 10% of the total pressure for a standard AC PDP cell with Xe fraction of $10{\sim}30%$.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.850-853
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• 2009

Many well-known pixel compensation circuits have been applied to control TFT $V_{th}$ variations on small size AMOLED panels. For large (>30-inch) AMOLEDs, luminance and color uniformity are affected by TFT variations, but also by ELVDD IR drop and cavity non-uniformity which are not easily compensated by in-pixel circuits. AMOLED panels may also suffer from manufacturing-induced mura. An external compensation method based on optical measurements is proposed and applied to large AMOLED panels. It improves luminance uniformity by up to 95% at 200nits and color uniformity by up to 99% (${\Delta}$u'v' <0.004) on large AMOLED panels, and provides-increased margin against processinduced mura.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.6
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• pp.1-8
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• 2006

The study is to analyze the surface luminance of the illuminated bridges according to the change of view point using luminance measurements with instrument CS-100 and ProMetric 1400. For the purpose the illuminated bridges of the structure type were sleceted. Also, the view points were classified the three types which are a perspective view, a building view, a driver view. The luminance of the surrounding sky, surface of river, upper structure or bridge, girder side, and pier or the objects was measured. As a result of this study, The Kwangjin and Dongho Bridge showed the luminance distribution of a perspective view was high. And the Olympic and Dongjac bridge the luminance distribution of building view was high. The luminance effect of the girder bridge that has no upper structure was distinguished for the perspective view, and the cable-stayed girder bridge and the arch bridge were characterized as the building view.

• International Journal of Highway Engineering
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• v.19 no.6
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• pp.165-173
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• 2017

PURPOSES : The current practice in car headlight visibility performance evaluation is based on the luminous intensity and illuminance of headlight. Such practice can be inappropriate from a visibility point of view where visibility indicates abilities to perceive an object ahead on the road. This study aimed at evaluating the appropriateness of current headlight evaluation method. METHODS : This study measured the luminance of object and road surface at unlit roadways. The variables were measured by vehicle type and by headlight lamp type. Based on the measurements, the distance where drivers can perceive an object ahead was calculated and then compared against such distance obtained by conventional visibility performance evaluation. RESULTS : The evaluation method based on illuminance of headlight is not appropriate when viewed from the visibility concept that is based on object-perceivable distance. Further, the results indicated a shorter object-perceiving distance even when road surface luminance is higher, thereby suggesting that illuminance of headlight and luminance of road surface are not the representative indices of nighttime visibility. CONCLUSIONS : Considering that this study utilized limited vehicle types and that road surface (background) luminance can vary depending on the characteristics of the given road surface, it would likely go too far to argue that this study's visibility performance evaluation results can get generalized to other conditions. Regardless, there is little doubt that the current performance evaluation criterion which is based on illuminance, is unreasonable. There should be future endeavors on the current subject which will need to explore study conditions further, under which more experiments should be conducted and effective methodologies developed for evaluating automotive headlight visibility performance. Needs are recognized particularly in the development of headlight visibility performance evaluation methodology which will take into account road surface (background) luminance and luminance contrast from various perspectives as the former indicates the driver's perception of the front road alignment and the latter being indicative of object perception performance.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.1
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• pp.142-146
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• 2007

Nowadays, itis inevitable trend to use high Xe gas contents for increase luminous efficiency and luminance in plasma display panel. However, the increase of Xe gas contents causes the driving voltage, although the brightness is increase. In this paper, we study the characteristics of electro optical according to Xe gas contents and gas pressure. Electro-optical characteristics were investigated by the discharge voltage, luminance and luminous efficacy measurements, respectively. With some increasing Xe gas contents and pressure, the electro-optical properties increased. However, the characteristics of electro-optical begin to be saturated, when too high increased Xe gas contents and pressure.

• Korean Journal of Materials Research
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• v.19 no.6
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• pp.313-318
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• 2009

Polymer Light Emitting Diodes (PLEDs) with an ITO/PEDOT:PSS/PVK/PFO-poss/LiF/Al structure were prepared on plasma-treated ITO/glass substrates using spin-coating and thermal evaporation methods. The annealing effects of the PFO-poss film when it acts as the emission layer were investigated by using electrical and optical property measurements. The annealing conditions of the PFO-poss emission film were 100 and $200^{\circ}C$ for 1, 2 and 3 hours, respectively. The luminance increased and the turn-on voltage decreased when the annealing temperature and treatment time increased. After examining the Luminance-Voltage (L-V) properties of the PLED, the maximum luminance was found to be 1497 cd/$m^2$ at 11 V for the device when it was annealed at $200^{\circ}C$ for 3 hours. The peak intensity of the PLED emission spectra at approximately 525 nm in wavelength increased when the annealing temperature and time of the PFO-poss film increased. These results suggest that the light emission color shifted from blue to green.