Authenticated sheet material

#This invention relates generally to encoded sheet material, and more particularly to systems and methods for managing encoded sheet material having information recorded thereon.

#Despite the publicity about the paperless office, paper remains an important media in today's working environment. Many efforts have been made to integrate paper documents with computer-based information systems. These efforts generally involve two scenarios. The first scenario involves scanning an existing physical document to create a digital copy, assigning a digital file name and then managing the digital copy as any other digital file. The second scenario involves creation of a physical document from an existing digital document or file such as by printing. To aid in the integration process, a barcode or a Dataglyph may be printed or otherwise attached to a physical document. Dataglyphs are generally less visually disruptive than barcodes. Both barcodes and Dataglyphs provide a means for the computer to grasp intentionally printed information on the paper document. Since both are generally applied at the time the information is recorded on the sheet of paper (but may be applied later through the use of an adhesive label), both generally appear on the same face of the sheet of paper as the recorded information.

#At the organization level, many documents, such as contracts, reports, files, technical documentation, etc., have to be physically stored for legal, administrative or operational reasons. Attention must be paid to their indexing and classification in order to keep document retrieval cost at an acceptable level. One solution is to physically attach a barcode or Dataglyph to an existing paper document and scan the document into the computer-based information system.

#FIG. 1 is a schematic of an example edge marking according to the invention;

#FIG. 2 is a diagram of a scheme for an edge marking including a ream marking and individual sheet marking;

#FIG. 3 is a perspective diagram of an edge reader reading an edge-marked sheet of material;

#Most sheets of material, such as paper sheets have six faces, two of them being commonly used: the so-called recto (first surface) and verso (second surface). The four other faces, the edges, may be used to uniquely identify each sheet and, optionally, the ream it comes, manufacturer and so on. If a ream identifier is used as part of the unique sheet code, each sheet in the ream will receive the same unique ream identifier, in addition to a unique sheet identifier. These identifiers can be marked with visible or invisible ink.

#Typical A4 paper sold today presents on the long and short edges a combined edge surface of 297×0.1 mm2 and 210×0.1 mm2, respectively. A robust code can be easily devised to fit within this size constraint. (A robust code is one, which can be easily read on the edge of a single sheet of material and also affords a sufficiently large number of codes for the anticipated amount of sheets of material to be used.) For example, a 64 bit long code made of 1 mm wide bars on a 2 mm grid would require 128 mm, which leaves enough room (say 64 mm for 32 bits of error code) for error correction code. In total this code (with error correction) would require 192 mm, and would also fit on letter size sheets (8½ inches by 11 inches). A typical edge thickness of 0.1 mm is sufficient height to write the bar constituting the code. For instance, to give an order of magnitude, the dots of a 600 dpi printer are 0.04 mm high. Two of these dots fit on the edge height of 0.1 mm. Thus the edge surface of typical paper sheets is thick and long enough to hold the example robust codes. A 64 bit long code provides enough unique codes to enable each inhabitant of the earth to consume 80,000 sheets of paper (material) per day for over 100 years.

#There are many schemes, which may be used to create a unique code to mark the edges of sheets of material. In addition to a unique sheet identifier, the edge code may also include information identifying the manufacturer, date of manufacture, a ream identifier, etc. Two specific examples will be described herein; however, the invention is not limited to only these two. The exemplary coding schemes described below include a unique sheet identifier and a ream identifier.