• Journal of Korean Vacuum Science & Technology
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• v.3 no.1
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• pp.90-94
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• 1999

Field Emission display (FEDs) require enhancement in both driving methods and process techniques to improve the display image quality. However, from the point of view of manufacturing, it is difficult to find methods and techniques to realize low cost manufacturing. New and simple color phosphor screen designs were suggested with non-crossed electrode lines and full color anode panels for small area displays were demonstrated. To avoid unwanted reaction with gases produced from phosphors in a high vacuum glass container, a very thin polyimide layer was coated on the phosphor screen. Moreover, to improve the display image quality, black matrix composed of inorganic materials was fabricated. This paper describes the performance and characteristics of the new full color anode panels.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.1
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• pp.179-184
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• 2014

The discharge characteristics of an open dielectric structure were investigated, especially such as a firing voltage and related wall voltage, compared with conventional panel structure based on the Vt close curve measurement in AC plasma display panel. While the front panel of the conventional structure in AC plasma display panel was composed of the glass, electrodes, and dielectric, the open dielectric structure could easily produce the discharge between the scan and the sustain electrodes by erasing the dielectric layer between two electrodes. As the open dielectric structure differ from the conventional structure, various problems were produced when driving with the conventional driving waveform. Especially, due to the changes in the discharge firing characteristics of the open dielectric structure between the scan and the sustain electrodes on the front panel, the conventional reset waveform including the address waveform needed to be modified. In this study, the Vt close curves were measured to compare the discharge firing voltages on three electrodes in the conventional and open dielectric structure and based on the Vt close curve analysis, the modified driving waveform suitable for the open dielectric structure was proposed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.6
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• pp.1175-1179
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• 2009

We analyze voltage characteristics of charged particle type display according to particle layers and cell gap between two electrodes and ascertain the aging effects by measuring the response time of particles with and without aging process. The threshold/driving/breakdown voltage is proportional to layers of charged particles and cell gap and the response time at driving voltage is faster than that of threshold and breakdown voltage because of different q/m of color and black particles. The analysis of response time is a method of estimation of optical characteristics, driving voltage and particle lumping and these results are promoted by aging process. We use the laser and photodiode to measure response time and optical properties. It has not been studied and reported to analyze the relationship of response time, threshold/driving/breakdown voltage, lumping phenomena, cell gap, and aging process for charged particle type display.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.38 no.5
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• pp.70-78
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• 2001

We have developed a novel driving system of 5' true color FED using voltage controlled PWM method which has current control effect. The proposed method has the advantage of voltage controlled pulse width modulation method and current control method. Also, we propose a new circuit model of FED subpixel for circuit simulation of FED driving circuits, considering some parasitic effects, i.e., cross talk, line coupling effect and leakage current to the adjacent cathode lines. Output stage of the data driving circuit is optimized using the proposed circuit model. In video data processing, FED controller uses the parallel processing of R.G.B input data, so duty ratio is maximized and brightness of FED increases. With this results, no noise and high quality performance is achieved in display of 5' true color FED.

• Journal of Information Display
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• v.1 no.1
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• pp.42-47
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• 2000

The relationship between driving voltage and the amount of wall charge in the address period of surface discharge type AC Plasma Display Panel has been investigated. The amount of wall charge on each electrode is obtained simultaneously from the current profiles after applying only one addressing discharge pulse. The wall charge $Q_y$ on the scan electrode Y is almost the sum of $Q_x$ on the address electrode X and $Q_z$ on the sustain electrode Z. The $Q_y$ increased with the driving voltage regardless of the kind of electrode, whereas the addressing $T_d$ decreased. The $Q_x$ and $Q_y$ are increased considerably by blocking voltage $V_z$, whereas $Q_x$ is decreased. The $V_z$ dependence of $Q_x$ $Q_y$ and ${\varrho}_z$ in addressing discharge was $-13{\times}10^{-2}$ (pc/$V_z$), and $60{\times}10^{-2}$ ($pc/V_z$) and $70{\times}10^{-2}(pc/V_z)$, respectively.

• 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.

• Journal of the HCI Society of Korea
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• v.1 no.1
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• pp.29-36
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• 2006

Tactile displays can provide useful information without disturbing others and are particularly useful for people with visual or auditory impairments. They can also complement other displays. In this paper, we present a new vibrotactile display device for wearable, mobile, and ubiquitous computing environments. The proposed vibrotactile device has a $5{\times}5$ array configuration for displaying complex information such as letters, numbers, and haptic patterns as well as simple directional ques and situation awareness alarms. Commercially available coin-type vibration motors are embedded vertically in flexible mounting pads in order to best localize vibrations on the skin. An embedded microprocessor controls the motors sequentially with an advanced tracing mode to increase recognition rate. User studies with the vibrotactile device on the top of the foot show 86.7% recognition rate for alphabet characters after some training. In addition, applying vibrotactile device to driving situation shows 83.9% recognition rate. We also propose some potentially useful application scenarios including Caller Identification for mobile phones and Navigation Aids for GPS systems while driving.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.11
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• pp.961-970
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• 2004

Tactile sensation is one of the most important sensory functions along with the auditory sensation for the visually impaired since it replaces the visual one of the persons with sight. In this paper, we present a tactile display device as a dynamic Braille display that is the unique tool f3r exchanging information among them. The tactile cell of the Braille display proposed is based on the dielectric elastomer, which is one of the electroactive polymers. It has advantageous features over the existing ones with respect to intrinsic softness, ease of fabrication, cost effectiveness and miniaturization. We introduce a new idea for actuation as well as additional considerations such as the driving circuit that makes it possible to drive multiple tactile cells in a high speed. Also, we describe the actuating mechanism of the Braille pin in details capable of realizing the enhanced spatial density of the tactile cells. Finally, results of psychophysical experiments are given to evaluate its effectiveness.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.4 no.1 s.6
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• pp.97-106
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• 2005

Since traffic engineering in 1950's, 'speed control technology' has experienced tremendous growth and developed constantly. However, speeding remains a major safety concern on many roadways. Many crashes is believed to be the result of driving too fast. Recently the speed reduction device, the speed monitoring display with ITS technologies have developed and introduced in many countries including our nation, Korea. Therefore This paper describes an evaluation of the use of a speed monitoring display, speed limit sign, and school zone sign. Two conditions were evaluated; without installation of Speed Monitoring Display, in Operation of Speed Monitoring Display.

• Journal of Information Display
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• v.10 no.2
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• pp.62-67
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• 2009

To understand panel driving more accurately, the optical properties and their distributions in the LCD panel itself, excluding the backlight, were investigated by measuring the transmittance of a one-dot pixel as a function of time. First, the behavior of time-dependent transmittance was analyzed, and it was found that the off-state TFT was not in a steady state but in a transient state during the holding period. Second, the time average, max, min, and range values of the transmittance curves were examined by varying the common voltage level and gray scale. Third, the analysis of such properties was expanded to cover those of the entire panel in all the gray scales. Lastly, the relationship between their properties and distributions was also investigated along with the contour plots.