Developer for electrophotographic copying

Abstract

Abstract PURPOSE:To always correct discrimination authenticity of paper money in a vending machine, etc., by adding a fluorescent substance to a developer. CONSTITUTION:A fluorescent substance is added to a developer for visualizing a latent image formed by charging a photoconductive receptor and exposing it. The fluorescent wavelength peak is kept <=420nm to render the fluorescent light white or colorless, and not to affect unfavorably the pattern and appearnce of a copy. Calcium tungstate, calcium magnesium arsenate, barium silicate, calcium phosphate, etc. are used as a fluorescent substance. An amount of it to be added is 5-50wt% based on a toner, and when an average particle diameter of the toner is 10 micrometers, size reduction of the fluorescent substance to 1 micrometer average particle diameter is sufficiently serviceable. Both are mixed in a V-type mixer after sufficiently pulverizing the substance in a mortar in advance, or the fluorescent substance and a synthetic resin may be melted and mixed by agitation.

Inventors

• 👤 Tsuneo Tashiro
• 👤 Takeshi Ishida

Bibliographic Details