I fully understand the term duty cycle, but I didn't bring it up because of possible confusion by an unfamiliar term. That exercise is left to those who might use those terms to shock and awe (or don't understand the audience). Why would you want to convert from digital to analog (except for CRT)? The kinds of transistors found in LSI and VLSI chips are typically not amplifiers -- they are binary switches. If they need to vary something, they do it using duty cycle. The signal is modulated into sinus radio frequencies. This is an analog process. Computer people might recognize this as something very much like a MODEM only at a much higher frequency. As for your understanding of how LCD works, here's an explanation from the leader in the use of the technology for TVs: http://sharp-world.com/sc/library/lcd_e/s2_1_1e.htm The key is not the twisting, but rather the spinning of the rods to an endwise orientation which allows the light to pass.