Abstract

In this paper, a novel two-dimensional adaptive dimming and current compensation technique with X-Y channels for light-emitting diode (LED) backlight system in LCD TVs is proposed. The proposed LED backlight has matrix structured LED modules with row and column switches to control the brightness of individual division block. It shows local dimming effects such as reduced power consumption and high dynamic contrast ratio even with much less number of LED drivers than that of the conventional two-dimensional local dimming method. Therefore, low cost and compact design of LED drivers can be achieved. This paper also contains a new adaptive dimming algorithm and image compensation technique for the proposed LED backlight system. Moreover, luminance difference among blocks caused by different I–V characteristics of LED and the luminance variation caused by temperature change are compensated by current sensing system. The proposed dimming technique is verified by simulation and experimental results based on a RGB-LED backlight of a 32-inch LCD TV.

© 2011 IEEE

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  2. http://www.rohs.gov.uk.
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  17. W. S. Oh, D. Y. Cho, K. M. Cho, G. W. Moon, B. C. Yang, T. S. Jang, "A novel two-dimensional adaptive dimming technique of X-Y channel drivers for LED backlight system in LCD TVs," J. Display Technol. 5, 429-432 (2009).

2010 (3)

2009 (3)

W. Lee, K. Patel, M. Pedram, "White-LED backlight control for motion-blur reduction and power minimization in large LCD TVs," J. Soc. Inf. Display 17, 37-45 (2009).

W. S. Oh, D. Y. Cho, K. M. Cho, G. W. Moon, B. C. Yang, T. S. Jang, "A novel two-dimensional adaptive dimming technique of X-Y channel drivers for LED backlight system in LCD TVs," J. Display Technol. 5, 429-432 (2009).

Y. K. Cheng, Y. H. Lu, C. H. Tien, H. P. Shieh, "Design and evaluation of light spread function for area adaptive LCD system," J. Display Technol. 5, 66-71 (2009).

2008 (1)

2004 (2)

W.-C. Cheng, M. Pedram, "Power minimization in a backlit TFT-LCD display by concurrent brightness and contrast scaling," IEEE Trans. Consumer Electron. 50, 25-32 (2004).

N. Chang, I. Choi, H. Shim, "Dynamic backlight luminance scaling of liquid crystal display," IEEE Trans. Very Large Scale Integr. (VLSI) Syst. 12, 837-846 (2004).

IEEE Trans. Consumer Electron. (1)

W.-C. Cheng, M. Pedram, "Power minimization in a backlit TFT-LCD display by concurrent brightness and contrast scaling," IEEE Trans. Consumer Electron. 50, 25-32 (2004).

IEEE Trans. Very Large Scale Integr. (VLSI) Syst. (1)

N. Chang, I. Choi, H. Shim, "Dynamic backlight luminance scaling of liquid crystal display," IEEE Trans. Very Large Scale Integr. (VLSI) Syst. 12, 837-846 (2004).

J. Display Technol. (5)

J. Soc. Inf. Display (2)

H. Chen, T. H. Ha, J. H. Sung, H. R. Kim, B. H. Han, "Evaluation of LCD local dimming backlight system," J. Soc. Inf. Display 18, 57-65 (2010).

W. Lee, K. Patel, M. Pedram, "White-LED backlight control for motion-blur reduction and power minimization in large LCD TVs," J. Soc. Inf. Display 17, 37-45 (2009).

Other (8)

T. Shiga, S. Mikoshiba, "Reduction of LCTV backlight power and enhancement of gray scale capability by using adaptive dimming technique," SID'03 Dig. (2003) pp. 1364-1367.

H. Chen, J. Sung, T. Ha, Y. Park, C. Hong, "Backlight local dimming algorithm for high contrast LCD TV," ASID'06 Dig. (2006) pp. 168-171.

T. Shirai, S. Shimizukawa, T. Shiga, S. Mikoshiba, "RGB-LED backlight for LCD-TVs with 0D, 1D, and 2D adaptive dimming," SID'06 Dig. (2006) pp. 1520-1522.

H. J. Peng, W. Zhang, C. K. Hung, C. J. Tsai, K. W. Ng, S. L. Chen, "High dynamic range LCD TV using active dynamic LED backlight," Proc. Asia Display 2007 (2007) pp. 429-432.

A. Konno, Y. Yamamoto, T. Inuzuka, "RGB color control system for LED backlight in IPS-LCD TVs," SID'05 Dig. (2005) pp. 1380.

A. Konno, Y. Yamamoto, T. Inuzuka, "RGB color control system for LED backlight in IPS-LCD TVs," SID'05 Dig. (2005) pp. 1380.

http://www.rohs.gov.uk.

I. Hwang, C. W. Park, S. C. Kang, D. S. Sakong, "Image synchronized brightness control," SID'01 Dig. (2001) pp. 492-493.

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