US Patent 7400989 RFID verifier system with grade classification

Patent 7400989 was granted and assigned to Printronix on July, 2008 by the United States Patent and Trademark Office.

Overview Structured Data Issues Contributors Activity

Is a

Patent

Patent attributes

Current Assignee

Printronix

Patent Jurisdiction

United States Patent and Trademark Office

Patent Number

74009890

Patent Inventor Names

Theodore A. Chapman0

Lihu M. Chiu0

Date of Patent

July 15, 2008

Patent Application Number

109515730

Date Filed

September 27, 2004

Patent Primary Examiner

‌

Manuel L. Barbee

Patent abstract

An RFID verifier includes a transmit signal strength indicator (TSSI) and a receive signal strength indicator (RSSI). Using the TSSI, the RFID verifier may determine the amount of power an interrogated RFID tag is illuminated with. Similarly, using the RSSI, the RFID verifier may determine the amount of power returned to the RFID verifier by the RFID tag. By processing the returned power and the illuminating power with a transfer function, the RFID verifier may provide an absolute indicia of quality for the interrogated RFID tag.