Skip navigation to main content. National Renewable Energy Laboratory (NREL)NREL HomeInnovation for Our Energy Future
About NRELScience and TechnologyTechnology TransferApplying TechnologiesLearning About Renewables
Technology Transfer
Technology Transfer Home About Technology Transfer Technology Partnership Agreements Licensing Agreements Nondisclosure Agreements Research Facilities Economic Development News

Electrochromic Projection and Writing Device

U.S. Patent 6,441,942


Technology Description

A display and projection apparatus includes an electrochromic material and a photoconductive material deposited in tandem used in conjunction with a light filtering means for filtering light transmitted through the electrochromic material. When an electric field is applied across the electrochromic material and the photoconductive material, light that is incident onto the photoconductive material through the surface of the projection apparatus causes the photoconductive material to conduct current locally in proportion to the amount of light incident on the photoconductive material. The flow of current causes the underlying portions of the electrochromic material to switch from an opaque state to a clear or transmissive state, thereby allowing back-light to propagate through the electrochromic material to create a visible image on the surface of the projection apparatus. Reversal of the electric field causes the electrochromic material to revert back to its opaque state, thereby blocking the transmission of back-light and effectively erasing the image from the surface of the projection apparatus.

Inventors

Howard M. Branz; David K. Benson

Interested in this Technology?

  • Browse related Patents, Trademarks and Copyrights
    • U.S. Patent 5,377,037 - Electrochromic-Photovoltaic Film for Light-Sensitive Control of Optical Transmittance
    • U.S. Patent 5,716,736 - Solid Lithium-Ion Electrolyte
    • U.S. Patent 5,384,653 - Stand-Alone Photovoltaic (PV) Powered Electrochromic Window
    • U.S. Patent 5,107,649 - Compact Vacuum Insulation Embodiments
    • U.S. Patent 6,169,246 - Photovoltaic Devices Comprising Zinc Stannate Buffer Layer and Method for Making
  • Read a complete description (PDF 275 KB) about how this technology has been applied. Download Adobe Reader.
  • See the full U.S. Patent for this technology.
  • NREL is looking for an organization to develop and commercialize this innovative technology. Interested organizations may consider developing/commercializing this technology through a license agreement, Cooperative Research Agreement, or Work for Others agreement. Please contact Richard Bolin at (303) 275-3028 for licensing, CRADA, and Work for Others opportunities.