Secure copier and method of reproduction

Abstract

A highly productive copier for use in a secure area or building is described. The copier includes a transparent electrical coil mounted either upon or within the copier's exposure platen and accompanying circuitry coupled thereto for detecting the proximity of metal such as those having magnetic or ferromagnetic properties. A document sheet fed to the platen for copying is sensed for the presence of the metal. Metal is present in confidential documents that have been made with metal containing toners and which are to be copied only by those authorized for copying same. A user identification system is provided for allowing users to identify themselves to the machine for allowing copying of confidential documents. Nonconfidential documents may be copied without requirement of identification. The copier is highly productive because it may be used with known high speed document feeders such as recirculating feeders without requiring a waiting period for the coil to be moved relative to the document. Copies made from the copier are reproduced either with metal containing toners for confidential documents or non-metal containing toners for non-confidential documents. A reproduction mode is also provided for allowing reproduction of documents not containing metal into copies which contain metal to create a detectable confidential document.