IPS lcd is better in contrast than TN TFT LCD:
IPS LCD is better than tft lcd in contrast, what is the reason? Because as we mentioned on the upper, IPS LCD is negative display mode, and the light can not transmit it when power off, it would be more black when in display off, IPS LCD is more easily to get the high contrast because it have more blacker background when in power off. Because the high contrast on IPS display, so IPS lcd can be more brilliant color image – this is a huge advance in technology than a Twisted Nematic (TN) display.
Which is better for power saving : IPS vs TFT LCD
TN TFT screen has more than around 20% power consumption than IPS tft. The reason from the array way of liquid crystal inside the IPS LCD. since the liquid crystal materials are arrayed in the plane, the power would be save for switching on liquid crystal in IPS than twist it in tft lcd, that is the reason IPS screen is better than TN lcd in power consumption.
Concerning the IPS tft have better contrast, but in the same time, it have smaller transmissive ratio, so we need more light from lcd backlight, if used more led chips, so it also need more power to the lcd backlight, so the total display module might need more power consumption if the backlight driving current for IPS LCD. so we need to more concern about the backlight current consumption instead of the IPS lcd lcd screen itself. The main power consumption would be from the lcd backlight, not the lcd screen.