Electrochromic projection and writing device

Patent · Tue Jan 01 04:00:00 EST 2002

OSTI ID:874691

Branz, Howard M ^[1]; Benson, David K ^[2]

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1. Boulder, CO
2. Golden, CO

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.

• Research Organization: Midwest Research Institute
• DOE Contract Number: AC36-83CH10093
• Assignee: Midwest Research Institute (Kansas City, MO)
• Patent Number(s): US 6441942
• OSTI ID: 874691
• Country of Publication: United States
• Language: English

Related Subjects

/359/
allowing
amount
apparatus
applied
back-light
blocking
causes
conduct
conductive material
conjunction
create
current
deposited
device
display
effectively
electric
electric field
electrochromic
electrochromic material
erasing
field
filtering
flow
image
incident
light
light transmitted
locally
material
means
opaque
photoconductive
portions
projection
propagate
proportion
reversal
revert
surface
switch
tandem
transmission
transmissive
transmitted
underlying
visible
writing