Authentication system for mail pieces

An improved system for authentication of mail pieces bearing bar-coded indicia, the system comprising first, second, and third bar-code readers, said first and third bar-code readers differing in that said first bar-code reader has a lower rate of successful reading of bar-coded indicia than said third bar-code reader, said second and third bar-code readers differing in that said second bar-code reader has a lower rate of successful reading of bar-coded indicia than said third bar-code reader,

• said system defining a first paper path through said first bar-code reader and subsequently through a first collator, said system disposed to collate a mail piece bearing an indicium in a second paper path in the event of a successful reading of said bar-coded indicium by said first bar-code reader, said system disposed to collate mail pieces in a third paper path in the event of an unsuccessful reading of said bar-coded indicium by said first bar-code reader, said third paper path leading to said third bar-code reader,
• said system defining a fourth paper path through said second bar-code reader and subsequently through a second collator, said system disposed to collate a mail piece bearing an indicium in a fifth paper path in the event of a successful reading of said bar-coded indicium by said second bar-code reader, said system disposed to collate mail pieces in a sixth paper path in the event of an unsuccessful reading of said bar-coded indicium by said second bar-code reader, said sixth paper path leading to said third bar-code reader
• said system disposed to collate mail pieces in a seventh paper path in the event of a successful reading of said bar-coded indicium by said third bar-code reader, said system disposed to collate mail pieces in an eighth paper path in the event of all unsuccessful reading of said bar-coded indicium by said third bar-code reader.