US 5,335,055 A · Bidirectional toning process

Abstract

A toning method for electrostatic printers and copiers where paper is wound on a supply roll and moved toward a takeup roll. After a latent image of a first color is written and the image area is wound toward a takeup roll, toner of a first color is applied while rewinding the image bearing web toward the supply roll. After the image area passes the writing head, the web is stopped and reversed so that a latent image corresponding to a second color may be written. Once the image region passes toning stations, the web is stopped and again reversed. During reverse direction travel of the image region, toner of a second color is applied and the image region is again wound on the supply roll. The process continues for toning all colors during the rewind operation. Although the image area may move at variable speeds during image writing, the image area is moved at constant speed in the reverse direction for toning. Motion at constant speed allows higher quality toners to be used, leading to improvement in color saturation and hue.

Claims14

Dependent claims

A method for forming a visible image comprising,

winding a web of image receiving material in a first direction from a supply roll toward a takeup roll,
reversing the direction of winding such that the web moves toward the supply roll in a second direction,
during web motion in the first direction, writing an electrostatic latent image on the web,
during web motion at a subsequent time in the second direction, applying toner to the latent image.

1 more element

Dependencies are inferred from the claim text.

Bidirectional toning process

Life of this patent

Bidirectional toning process

Life of this patent

Abstract

Claims14