Here’s a short video I’ve made so that you can compare the two different types of Sharp Memory LCD side-by-side. On the left is the 128 x 128 pixel HR-TFT type and on the right is the 96 x 96 pixel PNLC version.
To quote from Sharp’s own literature:
Sharp’s Polymer Networked Liquid Crystal (PNLC)-type Memory LCD is composed of a PNLC layer formed between a transparent surface electrode and mirror-reflective pixel electrodes. The PNLC module uses a scattering mode and does not require polarizers, which results in a very bright reflective display. A 1-bit memory circuit is embedded into each pixel, which retains the pixel information once it’s written.
Sharp’s high-contrast HR-TFT technology adds a polarizer to the top layer to greatly enhance the contrast of the display. The black level is dramatically enhanced, resulting in an almost paper-like black and white image.