Abrasion development

摘要

This invention relates to image developing apparatus and specifically a developer roll for use in combination with a color producing substrate. In accordance with this invention, a color is formed by the reaction of isolated chromogenic materials. A first chromogenic material is typically a color precursor of the electron donating type and is encapsulated with a photosensitive composition on the surface of an imaging sheet. The second chromogenic material is typically identified as a color developer and is generally of the electron accepting type. In this invention the active coating on the imaging sheet is abraded to rupture the capsules and promote the reaction of the color forming ingredients.