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Process for a Photo Induced Electrochromic Display

IP.com Disclosure Number: IPCOM000086539D
Original Publication Date: 1976-Sep-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Jones, HL: AUTHOR [+2]

Abstract

In obtaining a display image by photo-induced electrochromism, the processes of photochemical dissociation (exposure of the latent image) and electrochemical enhancement (image development) can be separated and assigned to two different materials.

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Process for a Photo Induced Electrochromic Display

In obtaining a display image by photo-induced electrochromism, the processes of photochemical dissociation (exposure of the latent image) and electrochemical enhancement (image development) can be separated and assigned to two different materials.

This separation of function has been accomplished by utilizing malachite green leucocyanide as one example of a species for photochemical dissociation according to the reaction: MGLC /h upsilon/ MG/+/ + CN/-/

This material exhibits photosensitivity in the 210-340 nm region of the spectrum with a quantum efficiency of unity, generates a cation (MG/+/) that is strongly absorbing in the visible at 622 nm, imparts sufficient conductivity to allow electrochemistry to occur, and exhibits full recovery to the leuco dye.

The process of electrochemical image enhancement is accomplished by utilizing a pyrazoline material which has been found to be stable to electrochemical cycling according to the reaction: Pz Pz/+/ + e The radical cation Pz/+/ exhibits strong absorption in the visible and is long-lived.

Photochemical oxidation of the pyrazoline does not occur since its peak sensitivity is at 400 nm and is sufficiently displaced from the malachite green leucocyanide (210-340 nm) as to be unaffected by the 325 nm exposing radiation.

A typical formulation for our process is:
0.020 molar malachite green leucocyanide
0.005 molar MeO-DEASP (1-p)-anisyl-3-diethylamino-

styryl-5-p)-diet...