Electrosensitive media and recording process

• US 4,596,635 A
• Filed: 08/26/1985
• Issued: 06/24/1986
• Est. Priority Date: 04/21/1982
• Status: Expired due to Term

• Current Assignee: Polyvision Corporation (Steelcase Incorporated), WARSZAWSKI, BERNARD, 122 AVEUE DE WAGRAM, PARIS, FRANCE
• Original Assignee: Hopkinson Associates Incorporated
• Inventors: Warszawski, Bernard
• Primary Examiner(s): Tufariello, T. M.
• Application Number:
  US06/769,172
• Time in Patent Office: 302 Days
• Field of Search: 204/2, 346/135.1, 346/165
• US Class Current: 205/50
• CPC Class Codes: B41J 3/4076 printing on rewritable, bistable "electronic paper" by a focused electric or magnetic field
• CPC Class Codes: G02F 1/1508 using a solid electrolyte

Abstract

An electrochromic material containing a hydrosoluble salt or a hydrosoluble mixture of salts of at least one metal cathodically depositable from an aqueous solution of its ions, an initially hydrosoluble film-forming polymer resin and water is developed by cathodic reduction of at least one depositable metal ion present within the electrochromic material at a point where a visible mark is desired.

Claims

1. A signal and image recording process comprising;

(1) providing a recording medium comprising an electrochromic material, which comprises a homogeneous mixture, having a solid consistency, and consisting essentially of

(a) a hydrosoluble salt or hydrosoluble mixture of salts of at least one metal cathodically depositable from an aqueous solution of its ions;

(b) an initially hydrosoluble film-forming polymer resin; and

(c) water;

the electrochromic material being able to develop by cathodic reduction of at least one depositable metal ion present within the electrochromic material metal marks, said metal marks electrocrystallizing as integral parts of the electrochromic material;

said electrochromic material being electroconductive;

(2) placing in contact with a free surface of the electrochromic material, at a place where a mark is to be made, a first electrode which is negatively polarized with respect to a second electrode also in contact with the electrochromic material in order to pass an electric current between both electrodes across the electrochromic material; and

(3) Passing an electric current between said electrodes whereby there is formed within the electrochromic material, in the area of contact with the first electrode, a visible mark by cathodically reducing depositable metal.

2. A process according to claim 1, including the step of forming within the electrochromic material a visible mark by cathodically reducing two co-depositable metal ions present within the electrochromic material into an alloy of said two metals which electro-crystallizes as an integral part of the electrochromic material.

3. The product of the process of any one of the claims 1 and 2.