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This paper studies high‐resolution AMOLED displays pixel and driving circuits using 3D stacking LTPS and oxide hybrid TFT integration technology systematically. It is demonstrated the OLED display resolution reaches 1167 PPI when the minimum line width/line spacing is reduced to 1 μm/0.5 μm. In addition, peripheral row and column drive circuits for the high display resolution were also illustrated. Good dynamic performance of the designed driving circuits was obtained thanks to the 3D TFTs. [ABSTRACT FROM AUTHOR]

The a‐IGZO TFTs integrated gate driver circuit with inter‐frame memory module and isolated bootstrapping node structure is proposed for AMOLED display. The driver can provide progressive display signal, inter‐frame detection signal and standby detection signal. Compared with conventional ones, the proposed inter‐frame memory shows enhanced driving ability due to the introduce of voltage bootstrapping function. Besides, the proposed gate driver can tolerate larger threshold voltage variations (ΔVth) than the conventional circuit due to the isolated bootstrap node structure. [ABSTRACT FROM AUTHOR]

This paper demonstrates a novel low‐temperature‐poly‐Si thin‐film transistors (LTPS TFTs) gate driver with tunable width for low‐grey level brightness adjustment of active‐matrix organic light‐emitting diode (AMOLED) display. The width of output pulses can be tuned accordingly by changing the number of input pulses, to avoid changing the frequency, duty ratio, or increasing the numbers of the external clock‐lines. The proposed circuit still works well when outputting 10 ms pulse with leakage current above 1.45 nA. [ABSTRACT FROM AUTHOR]

An OLEDoS microdisplay system is proposed in this paper, which includes a voltage‐driving pixel circuit, an OLED threshold voltage detection method, and a fast‐progressive compensation scheme. The measurement result shows that the range of the programming display voltage of the proposed voltage‐driving pixel circuit is 5.15 times larger than the gate‐source voltage difference of the driving transistor. The measured lowest current of a pixel can be as low as 2.89 pA. [ABSTRACT FROM AUTHOR]

In this work, we proposed a voltage‐programmed AMOLED pixel circuit using amorphous InGaZnO thin‐film transistors (a‐IGZO TFTs). For every display frame, thanks to the capacitive coupling method, the gate‐source voltage of the driving transistor is programmed through a zero to a positive value process, i.e. a unipolar sweeping direction is maintained for the driving transistor, to suppress the electrical hysteresis effects. In addition, the threshold voltage variation of the driving transistor can also be compensated through a source follower structure. Simulation results indicate that the relative current error is less than 30% for threshold voltage variations of ± 0.4 V. [ABSTRACT FROM AUTHOR]

A robust a‐IGZO TFT integrated gate driver for AMOLED is proposed. The emission driver and dynamic inverter share the pull‐up and pull‐down parts, which features enhanced charging and discharging ability. The driver provides not only multiple control signals for internal compensation, but also increased threshold voltage margin. [ABSTRACT FROM AUTHOR]

A new source driving circuit to compensate characteristics variations of thin-film transistors for AMOLED displays with high resolution is presented in this brief. The second-generation current conveyor is implemented for rapid current sensing of the feedback line, which is biased with a constant reference-voltage ($V_{{\mathrm{ REF}}}$). Further, the current difference between the current of the driving transistor (${I}_{ {D}}$) and the programming current, i.e., ${I}_{{\mathrm{ DATA}}}$ , is converted into switching voltage through an amplifier with a shorted resistor, to control the input of a ramp voltage (${V}_{{\mathrm{ RAMP}}}$). Thus, the degradations in electrical characteristics of the driving transistor can be compensated in real time, and both the influence of threshold voltage (${V}_{{\mathrm{ TH}}}$) shift and mobility (${ {\mu }}$) variation are effectively suppressed. The current-error rate of the proposed circuit is less than 3% with ${V}_{{\mathrm{ TH}}}$ shift of ±0.5 V or ${ {\mu } }$ variation of ±15%. In addition, the settling time is less than $4~{ {\mu } }{\text s}$ with the panel loading of 1.5 $\text{K}{ {\Omega }}$ and 100 pF at the OLED current (${I}_{{\mathrm{ OLED}}}$) levels ranging from 3 ${ {\mu }}\text{A}$ to 200 nA. [ABSTRACT FROM AUTHOR]

An IGZO TFTs integrated gate driver with an independent bootstrapping structure and an independent control unit is proposed for AMOLED display. The driver can output both programmable multi‐pulse scan signals and normally‐high‐voltage emission control signals. Compared with the traditional bootstrapping node structure with a long rising time of 1.06 µs, and the diode‐connected bootstrapping node structure with a long falling time of 1.60 µs, the proposed driver has a short and symmetric rising and falling time of about 0.64 µs. Cascaded simulation results show that the driver may be applicable to 5.5‐in full HD AMOLED panel. [ABSTRACT FROM AUTHOR]

The a‐IGZO TFTs integrated gate driver being compatible depletion‐mode device is proposed for AMOLEDs. The circuit features a bootstrapping inverter, which is initialized by global signal and controlled by cascading gate‐driving signals. Two sets of clocks with different low voltages are employed. Enhanced stability and reduced power consumption is thus resulted. The circuit can generate ultra‐wide compensation signals for AMOLED displays even with Vth of ‐6 V. [ABSTRACT FROM AUTHOR]

The a‐IGZO TFTs integrated gate driver on array with depletion‐mode compatible is proposed for AMOLEDs. The driver features a bootstrapping inverter, which is initialized by global signal and controlled by cascading signals. Greatly enhanced stability and pull‐down ability of the circuit is thus resulted. The driver functions well even with Vth of ‐5V and ripple on the output is reduced to 27.4%. [ABSTRACT FROM AUTHOR]

An a‐IGZO TFTs integrated gate driver with programmable output waveform for AMOLED display is proposed by shared input shift registers and output stages of multiple clock‐follower structure. The driver provides not only multiple scan and control signals for internal compensation, but also extended scan pulses for external compensation. [ABSTRACT FROM AUTHOR]

Using low-temperature poly-silicon thin-film transistors (LTPS TFTs) as a basis, a pixel circuit for an active matrix organic light-emitting diode (AMOLED) with narrow bezel displays was developed. The pixel circuit features mono-type scanning signals, elimination of static power lines, and pixel-integrated emitting control functions. Therefore, gate driver circuits of the display bezel can be simplified efficiently. In addition, the pixel circuit has a high-resolution design due to an increase of the pulse width of the scan signal to extend the threshold voltage and internal–resistance drop (IR drop) detection period. Further, regarding the influences of process–voltage–temperature (PVT) variation in the pixel circuit, comparison investigations were carried out with the proposed circuit and other pixel circuits with mono-type scanning signals using Monte Carlo analysis. The feasibility of the proposed pixel circuit is well demonstrated, as the current variations can be reduced to 2.1% for the supplied power reduced from 5 V to 3 V due to IR drop, and the current variation is as low as 10.6% with operating temperatures from –40 degrees to 85 degrees. [ABSTRACT FROM AUTHOR]

A precision bandgap reference (BGR) with high power supply ripple rejection (PSRR) and low temperature coefficient (TC) is proposed for the peripheral compensation circuitry of active-matrix organic light-emitting diode (AMOLED) displays. The PSRR is enhanced by a coupling structure of the power supply and a feedback loop of the start-up circuit. Furthermore, a high-order nonlinear compensation method is proposed to reduce the temperature coefficient by utilizing the systematic nonlinear offset voltage within the bandgap circuit. Measurement results of the proposed BGR implemented in an industrial 0.25-μm CMOS process demonstrate a TC of 4.99 ​ppm/°C in a wide temperature range of −40 ​°C–130 ​°C. A PSRR around −80 dB is also achieved by the proposed circuit at low frequency. [ABSTRACT FROM AUTHOR]