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We report the controllable UV-Visible-to-NIR Si-nanocrystals photonic sensor, photo-spectrum band-gap engineering technology, and integrated in TFT-LCD as multi-function intelligent display. Photonic Sensor using Si-nanocrystals as sensitizer sandwiched between two electrodes structure is proposed to integrate optical input function for new application in next generation mobile devices. The optical input function, used for image scanner, fingerprint recognition, and touch-input application, are achieved by integrating these image sensor elements within each display pixel. A 2-transistor (2T) active pixel sensor (APS) is used to integrate a VGA (> 250 dpi) image sensor within an LCD panel.

This paper presents an amplitude-shift-keying (ASK) demodulator for RF identification tags, which can be embedded on panel displays. The ASK demodulator was implemented in 3-mum low-temperature polycrystalline silicon (LTPS) thin-film transistor (TFT) technology. Since the threshold voltages of LTPS TFTs are higher than CMOS transistors, the conventional demodulator implementation will degrade the demodulator sensitivity significantly. The novel full-wave demodulator circuit was proposed to resolve the issue of high threshold voltage and reduce the ripples of the demodulated envelope. Operated at 8 V, the demodulator consumes 1.6 mW of power. The input carrier frequency was tested up to 13.56 MHz, and the highest ASK modulated data rate is 100 kb/s. The circuit size of the LTPS TFT demodulator is 500 mum times 450 mum.

A phase-locked loop (PLL) with self-calibrated charge pumps (CPs) has been fabricated in a 3-mum low-temperature polysilicon thin-film transistor (LTPS-TFT) technology. A voltage scaler and self-calibrated CPs are used to reduce the static phase error, reference spur, and jitter of an LTPS-TFT PLL. This PLL operates from 5.6 to 10.5 MHz at a supply of 8.4 V. Its area is 18.9 mm2, and it consumes 7.81 mW at 10.5 MHz. The measured static phase error without and with calibration is 80 and 6.56 ns, respectively, at 10.5 MHz. The measured peak-to-peak jitter without and with calibration is 3.573 and 2.834 ns, respectively. The measured reference spur is -26.04 and -30.2 dBc without and with calibration, respectively. The measured maximal locked time is 1.75 ms.

The traidational 3D interactive sysetm which uses CCD camera to capture image is difficult to operate on near range for mobile applications.Therefore, 3D interactive display with embedded optical sensor was proposed. Based on optical sensor based system, we proposed four different methods to support differenct functions. T mark algorithm can obtain 5- axis information (x, y, z,θ, and φ)of LED no matter where LED was vertical or inclined to panel and whatever it rotated. Sequential mark algorithm and color filter based algorithm can support mulit-user. Finally, bare finger touch system with sequential illuminator can achieve to interact with auto-stereoscopic images by bare finger. Furthermore, the proposed methods were verified on a 4-inch panel with embedded optical sensors.

A bandgap voltage reference (BGR) circuit designed with the low-temperature polycrystalline silicon (LTPS) thin-film transistors (TFTs) on glass substrate is proposed, which has been successfully verified in a 3-mum LTPS process. The experimental results have shown that the measured temperature coefficient of the new proposed bandgap voltage reference circuit is around 195 ppm/degC under the supply voltage of 10 V. The proposed bandgap voltage reference circuit can be applied on precise analog circuits for System-on-Panel (SoP) or System-on-Glass (SoG) applications.

We have developed a new AMLCD with multiple ambient light sensors (ALSs) for reducing backlight (BL) power consumption, and false sensing of ambient illuminance. ALSs perform well in showing BL control for power-saving, even though one of the sensors is covered by a finger shadow. Architecture of integrated ALS with a-Si and LTPS technologies are presented. We fabricate the in-cell, and wide-dynamic-sensing ALSs display using new light sensor technology. Photo-electrical characteristics with well linearity and reliability under long-term operation were observed.

An on-panel readout circuit for touch panel application has been designed and fabricated in a 3-μm low temperature poly-silicon (LTPS) technology. The minimum detectable voltage difference of the proposed circuit is 30 mV. The switch-capacitor technique is applied to amplify the voltage difference from capacitance change due to touch panel. The corrected double-sampling (CDS) technique is also employed to reduce the offset originated from process variation.

A new 3D interactive display system with embedded optical sensor has been proposed. This study focus on a lighting mode which uses LED light source as a 3D interactive device. Lighting mode is not affected by ambient light from the environment because extra LED is used. Changes of LED light shapes determine LED 3D coordinate in captured images are insufficient when LED position is in inclined direction or has a rotation angle. Therefore, a new algorithm was demonstrated to calculate LED position (X,Y,Z) where inclined angles were from θ=0° ∼ θ=40° and between 1cm∼5cm on 2.83 inch panel. Additionally, unlike the current 3D interactive systems, this paper proposed 3D interactive display can interact as 2D and 3D touch function simultaneously.

A delta-Sigma analog-to-digital (A/D) converter designed and implemented with the thin-film transistors (TFTs) on glass substrate is proposed, which has been successfully verified in a 3-μm low-temperature polycrystalline silicon (LTPS) process. The experimental results have shown that the probability in the bit stream of the digital output from the delta-Sigma modulator is correctly fit in the analog input voltage ratio. Such a bit stream can be converted into 8-bit digital code successfully under the operation voltage of 10V with thin-film transistors (TFTs) on the glass substrate. The proposed delta-Sigma A/D converter can be further used to achieve the precise analog circuits for System-on-Panel (SOP) or System-on-Glass (SOG) applications, which enables the analog circuits to be integrated in the active matrix LCD (AMLCD) panels.

The characteristics including intrinsic property of a-Si -TFT and LTPS TFT for the application used as OLED backplane are reviewed. Though a-Si AMOLED shows better uniformity and is capable of driving OLED, the stability of a-Si TFT under operation is still not acceptable, while LTPS TFT reveals satisfactory stability in AMOLED application. The stability of TFT under long-term operation is remained to be the key issue for commercialization of a-Si TFT AMOLED.

The characteristics of OLED backplanes including the intrinsic properties of a-Si TFTs and LTPS TFTs will be reviewed. While LTPS TFTs reveal satisfactory stability in AMOLED-display applications, a-Si AMOLEDs show better uniformity and are capable of driving OLEDs. However, the stability of a-Si TFTs under long-term operation is still unacceptable and remains to be the key issue constraining the commercialization of a-Si TFT AMOLEDs.

A new 6.8-inch 6-bit digital-type current driven active matrix organic light emitting diode (AMOLED) display was developed using low temperature poly-Si (LTPS) technology. We propose a new LAAT sample/hold structure and sharing method of D/A converter. The new LAAT sample/hold structure solves the low current gray level writing capability issue, which is due to the large parasitic capacitance of data line by providing sufficient charging time. The new sharing method of D/A converter saves power and layout size at the same time.