Shoot‐through current reduction scheme for low power LTPS TFT programmable shift register

Abstract

This paper proposes a programmable pulse width shift register where an output pulse width is adjusted only by changing a start pulse width without any additional signals and reconfiguration for the pre‐charging scheme of high resolution and high frame rate active‐matrix flat‐panel displays. In addition, the overall power consumption of a proposed circuitry is dramatically reduced by alleviating the shoot‐through current of an interval inverter, compared with the previous shift registers with the programmable or fixed output pulse width. The proposed shift register is verified by the simulation program with integrated circuit emphasis (SPICE) simulation at low temperature poly‐Si thin film transistor process for 50 stages. The proposed shift register lessens the power consumption by 34% and 54% for the output pulse widths of two and 10 line times, respectively, compared with those of the previous shift register structures.

Pulse-width-independent low power programmable low temperature poly-Si thin-film transistor shift register

“…As illustrated in Fig. 6, the power consumption is [9]. The power reduction ratios are estimated 60.5% and 88.6% for output pulse widths of two and ten line times, respectively.…”

“…When CLK1 is provided to one stage, CLK2 is connected to a next stage. The key differences between proposed and previous schemes [9] are Q[n] discharging path and NOT-AND circuit. In the previous programmable shift register depicted in Fig.…”

“…This paper presents a programmable pulse width LTPS TFT shift register that achieves the lower constant power consumption regardless of pulse width along with the reduced number of TFTs compared to a previous programmable shift register [9]. Fig.…”

“…Consequently, the output pulse width is programmed in accordance to the clock pulse width. On the other hand, a programmable pulse width low temperature poly-Si (LTPS) TFT shift registers have been proposed to adjust the output pulse width only by changing a start pulse width without any additional clock signals and circuit modification [9]. The programmable shift register enables multi-rate panels of low fabrication cost which can be employed at various frame rate applications such as 60 Hz, 120 Hz, and 240 Hz, by means of the pre-charging scheme of variable overlap intervals.…”

Adaptive one-dimensional dimming technique for liquid crystal displays with low power consumption and high image quality

“…[1][2][3][4][5][6] To reduce power consumption while increasing image quality in LCDs, various technologies have been studied such as backlight dimming, [7][8][9][10][11][12][13][14][15] inversion methods, [16][17][18] and charge sharing methods. [19][20][21][22][23][24] Based on a demand for slim designs and low power consumption, a side-lit light-emitting diode (LED) backlight unit (BLU) has been widely adopted not only in mobile LCD applications but also in large LCDs.…”