This work presents a fall detection system that is worn on the head, where the acceleration and posture are stable such that everyday movement can be identified without disturbing the wearer. Falling movements are recognized by comparing the acceleration and orientation of a wearer’s head using prespecified thresholds. The proposed system consists of a triaxial accelerometer, gyroscope, and magnetometer; as such, a Madgwick’s filter is adopted to improve the accuracy of the estimation of orientation. Moreover, with its integrated Wi-Fi module, the proposed system can notify an emergency contact in a timely manner to provide help for the falling person. Based on experimental results concerning falling movements and activities of daily living, the proposed system achieved a sensitivity of 96.67% in fall detection, with a specificity of 98.27%, and, therefore, is suitable for detecting falling movements in daily life.
This paper presents a new low-power gate driver circuit designed by hydrogenated amorphous silicon thin-film transistors (a-Si:H TFTs). An attempt is also made to reduce the power consumption resulting from the high-frequency pulldown structure, in which a pair of 0.25-Hz clock signals is used to implement a low-frequency and synchronously controlled pull-down scheme for recovering the threshold voltage shifts of a-Si:H TFTs under the negative gate-to-source voltage and decreasing the used TFTs. Measurement results indicate that the proposed gate driver circuit consumes 98.7 µW/stage, and the output waveforms are very stable without distortion when the proposed circuit is operated at 100°C for 840 h. Furthermore, the feasibility of the proposed gate driver circuit is demonstrated for the quad-extended-video-graphics-array resolution.Index Terms-Gate driver circuit, power consumption, quad-extended video graphics array (QXGA), threshold voltage shift.
This work proposes a new gate driver circuit for use in in-cell touch panels driven with the time division driving method. The charges are stored in the inserted stage of the gate driver circuit during the suspended display operation for activating the following stage. According to the measured transfer characteristics of the amorphous indium-gallium-zinc-oxide thinfilm transistor (a-IGZO TFT), stable and uniform output waveforms can be generated after the touch sensing period.
Author Keywordsgate driver circuit, in-cell touch, amorphous indium-gallium-zincoxide thin-film transistor (a-IGZO TFT). Fig. 5. G [n+1] waveforms generated without and with inserted stage when V TH of T2 N+1 and T2 M are shifted.
This work proposes a new active-matrix organic light-emitting diode (AMOLED) pixel circuit using an in-pixel mobility compensation technique. Moreover, the circuit can compensate for both power line voltage drop and threshold voltage variation. Thus, it is suited for backplanes utilizing p-type low-temperature polycrystalline-silicon thin-film transistors (LTPS TFTs). Simulated results demonstrate that the compensation functions are succeed at a Full HD (1920×1080) resolution with a 60 Hz frame rate. The current error rates of power line voltage drop and threshold voltage variation are all below 3%, and those of mobility variation are below 6.5%.
Author Keywordsactive-matrix organic light-emitting diode (AMOLED), lowtemperature polycrystalline-silicon (LTPS), thin-film transistor (TFT).
This work investigates the long-term behavior of photo thin-film transistors (TFTs) that are covered with color filters and based on hydrogenated amorphous silicon (a-Si:H) technology. Based on the electrical characteristics and the optical responses of these TFTs as measured under different stress conditions, a new method for driving a photo TFT with a negative gate-source voltage is proposed to suppress the degradation of the photocurrent. The effectiveness of the newly proposed method is verified using our previously developed white-light photocurrent gating (WPCG) structure, the measurement of photocurrents, and the established models of red, green, and blue photo TFTs. An accelerated lifetime test of the fabricated circuit was carried out at 70 • C and under the illumination of ambient light for 504 hours, demonstrating that the proposed method improves the long-term reliability of optical sensors.INDEX TERMS Hydrogenated amorphous silicon thin-film transistor, long-term reliability, optical sensor.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.