Motorola Labs Creates a New Display

SCHAUMBURG, Ill., March 29 – Researchers at Motorola Labs have demonstrated a new display mechanism, called Electrically Tunable Color (ETC) for color reflective liquid crystal displays (RLCD). According to the company the ETC has the potential to significantly improve the appearance of RLCDs. These are the most widely used displays for portable electronic products, such as cell phones and PDAs. Although these displays are popular with electronics manufacturers because of their low power consumption, they are not currently able to deliver the rich color, contrast and brightness that consumers prefer.
The ETC developed at Motorola Labs uses an in-plane electrical field to change the color of light reflected from a cholesteric liquid crystal material between two glass plates. A cholesteric liquid crystal has molecules coiled like springs between the glass plates. The distance between the successive rings of the spring determines the color of light reflected by the liquid crystal material. An electric field, applied parallel to the glass plates (in-plane), effectively untwists it, causing the separation between the rings to increase. This change produces an observable color shift.
All three primary colors have been demonstrated using a single layer of cholesteric liquid crystal by changing the in-plane voltage.