Enhancement of Brightness Uniformity by a New Voltage-Modulated Pixel Design for AMOLED Displays

This letter presents a new pixel design and driving method for active-matrix organic light-emitting diode (AMOLED) displays using low-temperature polycrystalline silicon thin-film transistors (TFTs). The proposed pixel circuit consists of five TFTs and one capacitor to eliminate the variation in the threshold voltage of the TFTs, and the drop in the supply voltage in a single frame operation by the source-follower-type connection and the bootstrap. The proposed pixel circuit has been verified to realize uniform output current by the simulation work using the HSPICE software. The novel pixel design has great potential for use in large-size and high-resolution AMOLED displays

[1]  Hiroyuki Miyake,et al.  P‐5: A Voltage Driving AMOLED Display with Luminance Control , 2005 .

[2]  Ya-Hsiang Tai,et al.  A new pixel circuit for driving organic light-emitting diode with low temperature polycrystalline si , 2005 .

[3]  Yen-Chung Lin,et al.  Improvement of brightness uniformity by AC driving scheme for AMOLED display , 2004, IEEE Electron Device Letters.

[4]  Hai-Jung In,et al.  P‐8: A Novel Feedback‐Type AMOLEDs Driving Method for Large‐Size Panel Applications , 2005 .

[5]  T. Ishibashi,et al.  24.4L: Late‐News Paper: A 13.0‐inch AM‐OLED Display with Top Emitting Structure and Adaptive Current Mode Programmed Pixel Circuit (TAC) , 2001 .

[6]  S. Pearson,et al.  The impact of the transient response of organic light emitting diodes on the design of active matrix OLED displays , 1998, International Electron Devices Meeting 1998. Technical Digest (Cat. No.98CH36217).

[7]  Min-Koo Han,et al.  A new voltage-modulated AMOLED pixel design compensating for threshold voltage variation in poly-Si TFTs , 2004 .

[8]  T. Sasaoka,et al.  24.4L: Late‐News Paper: A 13.0‐inch AM‐OLED Display with Top Emitting Structure and Adaptive Current Mode Programmed Pixel Circuit (TAC) , 2001 .

[9]  Chul-Hi Han,et al.  A new pixel circuit for active matrix organic light emitting diodes , 2002, IEEE Electron Device Letters.

[10]  O. Prache,et al.  Polysilicon VGA active matrix OLED displays-technology and performance , 1998, International Electron Devices Meeting 1998. Technical Digest (Cat. No.98CH36217).

[11]  Jin Jang,et al.  P‐72: A Novel Pixel Circuit for Active‐Matrix Organic Light‐Emitting Diodes , 2003 .

[12]  Philip C. H. Chan,et al.  The effects of grain boundaries in the electrical characteristics of large grain polycrystalline thin-film transistors , 2002 .