Browse Prior Art Database

Superthreshold Impact Heat Printing

IP.com Disclosure Number: IPCOM000098565D
Original Publication Date: 1959-Apr-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Prater, MP: AUTHOR

Abstract

In conventional heat printing methods information is printed on heat sensitive copy paper by heating selected areas of the copy paper until the temperature exceeds the color change threshold. The heating may either be accomplished by the reflex action of infrared radiation, which is converted to heat by the infrared-absorbing areas of the original, or it may be accomplished by pressing heated type slugs or other heated writing instruments against the heat sensitive paper.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 1

Superthreshold Impact Heat Printing

In conventional heat printing methods information is printed on heat sensitive copy paper by heating selected areas of the copy paper until the temperature exceeds the color change threshold. The heating may either be accomplished by the reflex action of infrared radiation, which is converted to heat by the infrared- absorbing areas of the original, or it may be accomplished by pressing heated type slugs or other heated writing instruments against the heat sensitive paper.

In the superthreshold method, printing is performed upon heat sensitive paper by first uniformly preheating the paper to a temperature just below its color change threshold and then striking the paper with type slugs, to locally raise the temperature of the paper above the color change threshold by the additional heat of impact. The initial preheating is accomplished in any suitable manner, such as either by exposure of the paper to infrared radiation or by means of a heated platen. If the color changes between 170 degrees F. and 180 degrees F., for example, the preheating of the paper should be sufficient to raise its temperature very close to the color changing temperature, and the heat of impact is sufficient to produce a color change, when a type slug strikes the paper.

1