Displays
Eastman Kodak has developed an "always on" plastic display. The device uses a bistable material that can retain an image without being attached to a power source. The company see applications in the retail and consumer markets such as signage and rewriteable badges.
The coated plastic is shatter-proof and offers a wide viewing angle. The technology is based on polymer dispersed cholesteric liquid crystals (PDChLC) applied to a flexible substrate. The liquid crystals have two stable energy states - on or off - and power is required only to change the image displayed.
Willy Shih, Display & Components president, comments: "By applying our expertise in how we manufacture film - using a roll-to-roll process - to display technology, Kodak is working to advance cost-effective, high-volume production of changeable displays." Kodak plans to have flexible film demonstration kits available later this year.
Universal Display (UDC) claims record-breaking power efficiencies for white organic light emitting diodes (OLEDs) using its phosphorescent OLED (PHOLED) technology. The advances were reported in a joint paper with Toyota Industries delivered at the 2004 Society for Information Display Conference in Seattle, Washington. Universal Display has been working with Toyota Industries since 2002 to develop PHOLED technology.
The paper reports a white PHOLED device with a luminous efficiency of 38cd/A and a power efficiency of 18.4lm/W at 1000cd/m2. Using a proprietary Universal Display white OLED (WOLED) structure, this device also demonstrates white emission with a colour rendering index (CRI) of 79.
PHOLED technology allows for up to 100% internal quantum efficiency, compared to the maximum 25% efficiency that can be obtained with conventional OLED technologies. Toyota's interest in PHOLED technology includes power-efficient, high-quality white lighting alternatives for liquid crystal display (LCD) backlighting.
