Energy-Efficient, Dual-Mode Displays and Active Devices

Technology #11604

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John Robert Reynolds
Managed By
Richard Croley
Assistant Director 352-392-8929
Patent Protection
US Patent 7,557,499
PCT Patent Application WO 2006/045043


The University of Florida is seeking companies interested in commercializing a new technology that makes screens, such as those on PDAs, cell phones and outdoor advertising, visible day or night while using less energy. As mobile devices gain popularity, users take their laptops and cell phones from indoors to outdoors, where they move from low ambient light situations to high ambient light/bright sunlight areas in a flash. More advanced concepts employ reflective and emissive displays embedded in switchable devices such as active windows and goggles. Extending battery life has also become a priority for consumers of mobile devices. The new displays developed by University of Florida researchers would enable the user to employ a reflective electrochromic mode, which requires little constant electrical current and extends battery life, in the bright light, and to switch to a light-emitting mode in dark environments.


Displays that emit light or change color making them visible day or night, including but not limited to: outdoor advertising signs, E-books, PDAs, cell phones, traditional computer screens, and emergency or safety lighting; emissive displays embedded in active windows and goggles


  • Illuminates without external light, reducing energy and materials costs
  • Uses minimal current in electrochromic mode, extending battery life and adding value for the customer
  • Allows users to read screens of PDAs, cell phones, computers and e-books day and night, providing a competitive advantage in the marketplace
  • Targets multiple and growing markets providing major profit potential


Conventional displays operate using one of two kinds of technologies: emissive or reflective. Displays and devices that operate well in darker conditions either emit light directly or use a back-lighting technology. Other devices that work well in bright conditions use reflective technologies (either electrochromic or liquid crystal), changing their color or reflection pattern of incident light. The new display technology developed by UF researchers uses both emissive and reflective technologies with electroactive material that acts as both the color-changing electrochrome and emissive layer without the need for a secondary light source. The display switches from one mode to the other by varying which pair of electrodes the electric field is applied across.

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