Patent ID: 8614804

Claim:
A document management system comprising: a document state storage unit that stores document state information representing states concerning document validity of electronic documents stored in a document storage unit; a manipulation control unit that refuses a request from a user for manipulating one of the electronic documents when the document state information corresponding to the one of the electronic documents indicates that the one of the electronic documents is invalid at present; a stamp image storage unit that stores a plurality of stamp images each respectively corresponding to one of the states represented by the document state information; an extracting unit that recognizes a read stamp image of a paper document inputted by the user, the read stamp image corresponds to one of the states represented by the document state information; a document ID recognizing unit that recognizes an electronic document having a given state corresponding to the paper document inputted by the user; and a state change unit that changes the given state of the electronic document based on the read stamp image of the paper document and its corresponding one of the states.