Thermally-activated receiving medium for use in a facsimile transmission system

A printing medium for the printing of images thereon to form a document by the printer of a standard facsimile machine in a manner which renders the document unreadable to a casual observer comprising:

• (a) a strip of a flexible printing medium receivable by the facsimile machine for passage therethrough past the printer thereof, said printing medium having a surface for receiving an image from the printer;
• and
• (b) a strip of an obscuring medium disposed over a surface of said printing medium so as to pass through the facsimile machine in combination with said printing medium, said obscuring medium having an obscuring portion covering a printing surface of said printing medium upon which the printer prints images for rendering printing on said printing medium unreadable to a casual observer;
• wherein the printer of the facsimile machine is adapted to print images on thermal paper by applying heat to a surface coating thereof which changes to a dark and visible color in response to the heat and wherein additionally,
• (c) said printing medium is a plain paper having a top surface;
• and,
• (d) said obscuring medium is a covering sheet covering said top surface of said plain paper, said covering sheet having a heat-transferable ink coating on a bottom surface thereof facing said top surface of said plain paper whereby when the printer applies heat to said obscuring medium said ink adjacent thereto is transferred from said obscuring medium to said top surface of said plain paper, said obscuring portion of said covering sheet containing means for preventing images produced on said top surface from being read through said obscuring medium at least by a casual observer.

In a transparency comprising a rectangular sheet of a transparent plastic material having a surface for accepting and holding an image of a document for use in a secure facsimile transmission system wherein one of two partial documents each containing portions of an original document which are complementary and mutually exclusive is copied onto the transparency and overlayed on the other of the two partial documents in registration therewith to recreate the original document, the improvement for making the transparency doubly useful in a receiver-controlled secure facsimile system comprising:

• (a) an adhesive material disposed at an edge and on a bottom surface of the sheet of plastic material;
• (b) a removable backing sheet disposed over said adhesive material so as to allow the transparency to pass freely through a copy machine and be slid on the surface of a document without said adhesive material interfering therewith whereby after copying the one of two partial documents onto the transparency and placing it in registration on the other of the two partial documents said backing sheet can be removed in situ to bond the transparency to the one of the two partial documents, said removeable backing sheet also covering the entire said bottom surface of the sheet of plastic material and being disposed such as to pass through a standard facsimile machine and past a printhead thereof, said removeable backing sheet also having an obscuring portion disposed over a printing surface of the transparency upon which the printer prints images for rendering printing on the transparency unreadable to a casual observer, said obscuring portion comprising an interference pattern on said backing sheet facing a bottom surface of the transparency to be seen through the transparency in combination with images produced on the transparency whereby the transparency can be used as the receiving medium in a standard facsimile machine to provide a receiver-controlled secure receiving environment.

A printing medium for the printing of images thereon to form a non-fading document by a thermal printer of a standard facsimile machine which cuts material from a roll printing medium into sheet lengths after printing thereon with a thermal printhead comprising:

• (a) a strip of a flexible, frangible, plain-surfaced printing paper receivable by the facsimile machine for passage therethrough past the printer thereof, said printing paper being cuttable by a sheet cutter of the facsimile machine;
• (b) a strip of a flexible, frangible, cover medium disposed over and rolled in combination with said printing paper so as to pass through the facsimile machine in combination with said printing paper, said cover medium being cuttable by the sheet cutter of the facsimile machine in combination with said printing paper;
• and,
• (c) a coating of a heat-transferable ink disposed on a central portion of a surface of said cover medium facing said printing paper, said ink being transferred from said cover medium to said printing paper upon the application of heat at a pixel position thereof by the thermal printhead of the facsimile machine.

A roll printing medium for printing by a thermal printer of a standard facsimile machine which cuts material from a roll printing medium into sheet lengths with a cutter after printing thereon with a thermal printhead comprising:

• (a) an elongated strip of a plain-surfaced printing paper;
• (b) an elongated strip of a cover medium disposed over said printing paper so as to pass through the facsimile machine in combination with said printing paper, said printing paper and said cover medium being rolled into a supply roll and being of flexible, frangible, materials which are in combination cuttable by the cutter of the facsimile machine;
• and,
• (c) a heat-transferable ink disposed as a coating on a central portion of a surface of said cover medium facing said printing paper, said ink being transferred from said cover medium to said printing paper upon the application of heat at a pixel position thereof by the thermal printhead of the facsimile machine.

In a facsimile transmission system whereby a document is sent between a sender and a receiver by facsimile and printed by a thermal printhead of a facsimile machine at the receiver, the improved printing media comprising:

• (a) a strip of a flexible printing medium receivable by the facsimile machine for passage therethrough past the printhead thereof, said printing medium having a surface for receiving an image from the printhead;
• and,
• (b) a strip of a covering medium disposed over a surface of said printing medium so as to pass through the facsimile machine in combination with said printing medium, said covering medium having a obscuring portion covering a printing surface of said printing medium upon which the printer prints images, said obscuring portion including means for causing heat produced by the printhead at positions of images to cause printing of said images at corresponding positions of said printing surface;
• and wherein,
• (c) said printing medium is a thermal paper having a top surface having a coating thereon which changes to a dark and visible color in response to heat;
• and,
• (d) said covering medium is a covering sheet covering said top surface of said thermal paper, said covering sheet having a high index of thermal conductivity and capable of quickly transmitting heat from the printhead vertically through said covering medium to said coating on said thermal paper, said covering sheet being of a frangible material whereby said covering sheet can be cut by a transverse cutter of a facsimile machine which cuts roll media into sheet lengths.

In a facsimile transmission system whereby a document is sent between a sender and a receiver by facsimile and printed by a thermal printhead of a facsimile machine at the receiver, the improved printing media comprising:

• (a) a strip of a flexible printing medium receivable by the facsimile machine for passage therethrough past the printhead thereof, said printing medium having a surface for receiving an image from the printhead;
• and
• (b) a strip of a covering medium disposed over a surface of said printing medium so as to pass through the facsimile machine in combination with said printing medium, said covering medium having a obscuring portion covering a printing surface of said printing medium upon which the printer prints images, said obscuring portion including means for causing heat produced by the printhead at positions of images to cause printing of said images at corresponding positions of said printing surface;
• and wherein,
• (c) said printing medium is a plain paper having a top surface;
• and,
• (d) said covering medium is a covering sheet covering said top surface of said plain paper, said covering sheet having a heat-transferable ink coating on a bottom surface thereof facing said top surface of said plain paper whereby when the printer applies heat to said covering medium said ink adjacent thereto is transferred from said covering medium to said top surface of said plain paper, said covering sheet being of a frangible material whereby said covering sheet can be cut by a transverse cutter of a facsimile machine which cuts roll media into sheet lengths.