QR-LPD stands for Quick Response - Liquid Powder display and is technology from Bridgestone (yes, the tire people). The is one of the implementations of E-paper.
Bridgestone has developed, for the first time in the world, Electronic Liquid Powder that has the characteristics of both powder and liquid. This "Electronic Liquid Powder" is highly fluid and is easily suspended. It also reacts sensitively to electricity.
 How it works
Positively charged black Electronic Liquid Powder and negatively charged white Electronic Liquid Powder are enclosed between transparent front and black plates. When the electric potential of the front plate is higher than that of the back plate, the white powder moves to the front plate and the display appears white. Conversely, when the electric potential of the front plate is lower than that of the back plate, the black powder moves to the front plate and the display appears black.
The viewing angle is very wide, thanks to the surface reflection characteristics of the powder adhering to the front plate. The charged Electronic Liquid Powder moves within the panel in response to the applied voltage. Because the material moves through air quickly, switching between white and black is possible in as little as 0.2msec.
This is bistable do the adherence of the material to the surface.
 For more information
Bridgestone Japan in English.