Patent ID: 8074164

Claim:
A document management device, connected to a plurality of reader terminals via a network, for managing a document circulated to a reader in accordance with a circulation tree and additional information added to the document by the reader, the circulation tree indicating a circulation order of a plurality of readers, the device comprising: a document circulation unit operable to send 0 th generation document data or note a storing location of the 0 th generation document data to a selected reader terminal, and to receive 1 st generation document data in which 1 st piece of additional information from a first reader associated with the selected reader terminal is added to the 0 th generation document data, according to circulation order of the circulation tree after the first reader, to send (nâˆ’1) th generation document data which cumulatively includes 1 st to (nâˆ’1) th pieces of additional information added to n th reader terminal, or note a storing location of the (nâˆ’1) th generation document data to the n th reader terminal, and to receive n th generation document data in which n th piece of additional information from n th reader associated with the n th reader terminal is added to the (nâˆ’1) th generation document data, wherein n is an integer not less than 2; a circulation information management unit operable to set the circulation tree indicating the circulation order of the plurality of readers, and to set a processing attribute with respect to each reader which is used to select one of a plurality of documents as a difference detection generation document, the difference detection generation document being an object of difference detection when extracting additional information; a recognition unit operable to recognize n th additional information which is extracted based on the difference between the n th generation document data and the difference detection generation document set based on the processing attribute; and an additional information management unit operable to store the n th additional information recognized in association with the 0 th generation document data, and to manage the 0 th generating document data in association with each additional information; wherein the circulation information management unit sets either authorization or comment as the processing attribute, when the processing attribute is authorization, the 0 th generation document data is set as the difference detection generation document, when the processing attribute is comment, the (nâˆ’1) th generation document is set as the difference detection generation document for the n th generation document.