E-Paper Displays

7Reflective LCD with Memory in Pixel Structure

Yoko Fukunaga

Senior Engineer, Panel Design Department, Japan Display Inc.

7.1 Introduction

Low‐temperature polycrystalline silicon (LTPS) is a well‐established backplane thin film transistor (TFT) technology used for flat panel displays. LTPS TFT technology allows us to integrate complementary MOS (CMOS) circuits onto the glass. Development of the system‐on‐glass (SOG) display using LTPS TFT liquid crystal displays (s) has been hot technology topics in the late 1990s and early 2000s. SOG technology allows us to integrate various functional circuits onto display panels, such as timing controllers, display drivers, and decoders.

Memory in pixel (MIP) LCD is one of the unique applications of SOG technologies. It is one of the best ways to reduce LCD driving power because this approach needs no image data refreshment when displaying still images [1–7].

Reflective LCD technology is also one of the best ways to reduce display power consumption. The backlight consumes a large amount of transmissive LCD's power. A reflective LCD utilizes environmental light and has no need to turn on an auxiliary light when the environment is bright enough.

MIP technology and reflective LCD technology are good combinations because MIP circuits can be integrated behind the reflective pixel electrode without sacrificing the reflective aperture ratio.

LTPS SOG technology makes it possible to integrate display interface circuits onto a glass border area. ...