Browse Prior Art Database

Copier Document Security

IP.com Disclosure Number: IPCOM000083109D
Original Publication Date: 1975-Apr-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Simpson, HW: AUTHOR

Abstract

The use of special conductive paper to record not-to-be-copied information produces an original which cannot be copied by an office copier, which is constructed to detect the presence of such a paper on its document glass. Conductive paper of this type can be made by the addition of an ionic salt, the use of a metal backed plain paper sheet, or the use of short lengths of foil on the back of a plain paper sheet.

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

Page 1 of 1

Copier Document Security

The use of special conductive paper to record not-to-be-copied information produces an original which cannot be copied by an office copier, which is constructed to detect the presence of such a paper on its document glass. Conductive paper of this type can be made by the addition of an ionic salt, the use of a metal backed plain paper sheet, or the use of short lengths of foil on the back of a plain paper sheet.

The copier includes a microwave source which is controlled by the copier's start button, to emit a pulse of microwave energy toward the document glass. If the document is of the type which is not to be copied, an echo pulse is received by a detector. This detector then operates to inhibit the copy process. If no echo is received, the document is copied.

If the copier included a metal lid, which closes over the original document to hold it against the copier's document glass, an electrical timing window is provided to control the detector, thereby allowing a document-produced echo to be sensed by the detector during the time period of this window, while inhibiting the detector's response to a later lid-produced echo.

1