Raised xerographic printing - for braille produced using intumescent electroscopic tower mixture

摘要

Raised images are produced by contacting an electrostatic latent image on a xerographic matl. with a dry, free-flowing, self-contained intumescent electroscopic toner mixture to develop the image, transferring the toner to a transfer surface and heating the transferred toner sufficiently to cause intumescence of it and provide and permanent raised image. The method is used for producing braille images, letter-heds and business cards. Raised images are produced cheaply and quickly (about 15 seconds) and faint images can be produced sharply with clean background.