Thermal imaging method

US5192645A · kind A · utility

Assignee

• Polaroid Corporation · US

Inventors

• Roger A. Boggs · Wayland, US
• Alan L. Borror · Andover, US
• Patrick R. Conlon · Wakefield, US
• Richard L. Cournoyer · San Francisco, US
• Ernest W. Ellis · Harvard, US
• David P. Waller · Lexington, US

Key dates

• Filing date: Jul 12, 1991
• Grant date: Mar 9, 1993
• Expiry date: Jul 12, 2011

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S430/165
• WIPO field: Textile and paper machines
• WIPO sector: Mechanical engineering

Abstract

A thermal imaging method for forming color images is provided which employs as the color image-forming material, a colorless precursor of a preformed image dye possessing at least one thermal protecting group that undergoes fragmentation upon heating and at least one leaving group that undergoes irreversible elimination upon heating, said protecting and leaving groups maintaining the precursor in its colorless form until heat is applied to effect removal of these groups whereby the precursor is converted to an image dye.