Driving passive‐matrix LCDs with low hardware complexity and reduced supply voltage

Abstract

-In passive-matrix liquid-crystal displays (LCDs), multiplexing is achieved by using the intrinsic non-linear characteristics of the liquid-crystal material. If the electro-optic characteristic is steeper than necessary for the matrix display, the selection ratio need not be maximized. Instead, the selection ratio can be reduced to match the electro-optic characteristics of the display. This leads to a reduction in the supply voltage of the drive electronics. We have considered the possibility of using addressing techniques with low hardware complexity along with displays having steep electro-optic characteristics. Supply voltages for these techniques are compared with that of multi-line addressing (MLA). The supply voltages of the Hybrid Addressing Technique (HAT), Improved Hybrid Addressing Technique-S3 (IHAT-S3), and Improved Hybrid Addressing Technique-S4 (IHAT-S4) are lower than that of MLA for the lower range of N. These hybrid addressing techniques with lower hardware complexity are a better choice for driving passive-matrix LCDs, especially in portable equipment.