The present invention provides OLEDs of the top emission type comprising organic light-emitting (LE) elements by preventing the problems such as the widening of the power lines, the reduction in the aperture ratio caused by the widening of the upper and the lower capacitor electrodes and the short circuit between the upper and the lower electrodes caused by the roughness of the flattening layers. Two kinds of the OLEDs are provided. One is an OLED comprising a region of LE layer sandwiched between the upper and lower electrodes is formed on a power line of TFT for driving the pixel. Another comprises a region of the LE layer formed on an electrode of capacitor connected to the TFTs to control the light-emitting element. Accordingly, without forming a flattening layer on the light-emitting layer, there is no electric short circuit between the lower electrode and the upper electrode.

Organic Light Emitting Display Device

A display device displays an image having a substantially uniform brightness by compensating for variations of the threshold voltages of driving transistors and compensating for the deterioration of an organic light emitting diode. A pixel includes an organic light emitting diode, two transistors, a storage capacitor, and a compensation unit. A driving transistor supplies a current to an OLED corresponding to the voltage in the storage capacitor. The compensation unit controls a voltage of a gate electrode of the driving transistor corresponding to a deterioration of the organic light emitting diode, and couples one electrode of the driving transistor to the data line during a compensation period, during which a threshold voltage of the driving transistor is compensated.

Pixel and organic light emitting display device using the same

In this paper a strapdown inertial navigation system (SINS) error model is introduced, and the observability of the SINS error model is analyzed. Then, on the basis of this SINS error model and the analysis of computer simulation results, a fast estimation method of the azimuth error /spl Phi//sub D/ is proposed for the initial alignment of SINS on stationary base. Consequently, the time of initial alignment is reduced greatly. The computer simulation results illustrate the efficiency of this fast initial alignment method.

A fast initial alignment method for strapdown inertial navigation system on stationary base

Alignment of the strapdown inertial navigation system (INS) has strong nonlinearity, even worse when maneuvers, e.g., tumbling techniques, are employed to improve the alignment. There is no general rule to attack the observability of a nonlinear system, so most previous works addressed the observability of the corresponding linearized system by implicitly assuming that the original nonlinear system and the linearized one have identical observability characteristics. Strapdown INS alignment is a nonlinear system that has its own characteristics. Using the inherent properties of strapdown INS, e.g., the attitude evolution on the SO(3) manifold, we start from the basic definition and develop a global and constructive approach to investigate the observability of strapdown INS static and tumbling alignment, highlighting the effects of the attitude maneuver on observability. We prove that strapdown INS alignment, considering the unknown constant sensor biases, will be completely observable if the strapdown INS is rotated successively about two different axes and will be nearly observable for finite known unobservable states (no more than two) if it is rotated about a single axis. Observability from a global perspective provides us with insights into and a clearer picture of the problem, shedding light on previous theoretical results on strapdown INS alignment that were not comprehensive or consistent.. The reporting of inconsistencies calls for a review of all linearization-based observability studies in the vast literature. Extensive simulations with constructed ideal observers and an extended Kalman filter are carried out, and the numerical results accord with the analysis. The conclusions can also assist in designing the optimal tumbling strategy and the appropriate state observer in practice to maximize the alignment performance.

Observability of Strapdown INS Alignment: A Global Perspective

Alignment of the strapdown inertial navigation system (INS) has strong nonlinearity, even worse when maneuvers, e.g., tumbling techniques, are employed to improve the alignment. There is no general rule to attack the observability of a nonlinear system, so most previous works addressed the observability of the corresponding linearized system by implicitly assuming that the original nonlinear system and the linearized one have identical observability characteristics. Strapdown INS alignment is a nonlinear system that has its own characteristics. Using the inherent properties of strapdown INS, e.g., the attitude evolution on the SO(3) manifold, we start from the basic definition and develop a global and constructive approach to investigate the observability of strapdown INS static and tumbling alignment, highlighting the effects of the attitude maneuver on observability. We prove that strapdown INS alignment, considering the unknown constant sensor biases, will be completely observable if the strapdown INS is rotated successively about two different axes and will be nearly observable for finite known unobservable states (no more than two) if it is rotated about a single axis. Observability from a global perspective provides us with insights into and a clearer picture of the problem, shedding light on previous theoretical results on strapdown INS alignment that were not comprehensive or consistent. The reporting of inconsistencies calls for a review of all linearization-based observability studies in the vast literature. Extensive simulations with constructed ideal observers and an extended Kalman filter are carried out, and the numerical results accord with the analysis. The conclusions can also assist in designing the optimal tumbling strategy and the appropriate state observer in practice to maximize the alignment performance.

The authors demonstrate that the stationary alignment of strapdown inertial navigation system (SDINS) can be improved by employing the multiposition/technique. Using an observability analysis, it is shown that an optimal two-position alignment not only satisfies complete observability conditions but also minimizes alignment errors. This is done by analytic rank testing of the stripped observability matrix and numerical calculation of the error covariance. It is also shown that an optimal three-position alignment accelerates the convergence of the alignment error compared with two-position alignment. >

Multiposition alignment of strapdown inertial navigation system

We present two types of touch in-cell technology for active-matrix liquid crystal displays (AMLCDs) with liquid-crystal capacitance detector arrays embedded in a hydrogenated amorphous silicon (a-Si:H)-based backplane. The scanning method can determine and provide multiple simultaneous touch locations on the basis of the information extracted from each sensing element. On the other hand, the crossing method provides the position information from the coordinate information such that the system complexity and power consumption are expected to be considerably reduced. In both cases, by limiting the operation of sensors to the subthreshold region, we expect that the degradation of a-Si:H thin-film transistors (TFTs) will be suppressed and reliability will be ensured. Their relatively simple architecture enables the proposed touch-panel function to be readily integrated within large-area displays.

Touch-Sensitive Active-Matrix Display with Liquid-Crystal Capacitance Detector Arrays

We have proposed a new poly-Si TFT pixel, which can suppress TFT leakage current effect on active matrix organic diode (AMOLED) displays, by employing a new circular switching TFT and additional signal line for compensating the leakage current. When the leakage current of switching TFT is increased, the V GS of the current driving TFT in the proposed pixel is not altered by the variable data voltages due to the circular switching TFT. Our simulation results show that OLED current variation of the proposed pixel can be suppressed less than 3%, while that of conventional pixel exceeds 30%. The proposed pixel may be suitable to suppress the leakage current effect on AMOLED display.

Suppression of TFT leakage current effect on active matrix displays by employing a new circular switch

We propose a new pixel structure employing solid-phase crystallized silicon thin-film transistors which suppresses the leakage current effects on active-matrix organic light-emitting diode (AMOLED) displays. The pixel structure has been fabricated on a glass substrate employing the field-enhanced rapid thermal annealing technology. In the proposed pixel, the charge holding capability is considerably enhanced due to the capacitor located between two series-connected switch transistors. Our experimental results shows that the average variation range of the OLED current is suppressed less than 0.5% while the conventional one exceeded 4%.

A New Thin-Film Transistor Pixel Structure Suppressing the Leakage Current Effects on AMOLED

— A new digital ambient-light sensor system is presented which employs two linear light sensors with different sensitivities and automatically adjusts the sensitivity based on the illumination condition. The adaptation mechanism allows a very wide range of light intensity to be detected, and the input dynamic range of the system is substantially improved from 22.5 to 45.1 dB. The proposed method does not require any additional precision bits for output data. Due to the small number of the output bits and the simple conversion process, the system can be easily integrated on the display panel.

Hyun-Sang Park

Papers

Multiposition alignment of strapdown inertial navigation system

Touch-Sensitive Active-Matrix Display with Liquid-Crystal Capacitance Detector Arrays

Suppression of TFT leakage current effect on active matrix displays by employing a new circular switch

A New Thin-Film Transistor Pixel Structure Suppressing the Leakage Current Effects on AMOLED

Ambient‐light sensor system with wide dynamic range enhanced by adaptive sensitivity control