Passive Matrix Addressing of TN Displays

A dc‐free addressing could be realized by using the addressing voltages with a reversed sign. This chapter represents matrix architectures for passive matrix (PM) addressed LCDs. To satisfy the rms condition, the response time of an LCD must be much larger than the address time of the electronic circuit. This was as a rule met by using slow LCDs which precluded the use of PM addressed displays for fast moving pictures, such as are present in TV. To render fast LCDs applicable, addressing based on short pulses has to be abandoned and replaced by addressing waveforms spread over the entire frame time. This was achieved by the Active Addressing proposed by Scheffer and Clifton and Scheffer and Nehring, and by the independently developed Multiple Line Selection by Ihara et al.