(19)
(11) EP 2 257 078 A8

(12) CORRECTED EUROPEAN PATENT APPLICATION
Note: Bibliography reflects the latest situation

(15) Correction information:
Corrected version no 1 (W1 A2)

(48) Corrigendum issued on:
30.03.2011 Bulletin 2011/13

(88) Date of publication A3:
05.01.2011 Bulletin 2011/01

(43) Date of publication:
01.12.2010 Bulletin 2010/48

(21) Application number: 10176543.6

(22) Date of filing: 16.01.2002
(51) International Patent Classification (IPC): 
H04Q 1/00(2006.01)
G08C 19/00(2006.01)
 G08B 13/14(2006.01)
G06K 19/07(2006.01)
(84) Designated Contracting States:
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

(30) Priority: 23.01.2001 US 768327

(62) Application number of the earlier application in accordance with Art. 76 EPC:
02705833.8 / 1358767

(71) Applicant: Single Chip Systems Corporation
San Diego, CA 92127 (US)

(72) Inventor:
  • Dalglish, David G.
    Longmont, CO 80501 (US)

(74) Representative: Viering, Jentschura & Partner 
Grillparzerstrasse 14
81675 München
81675 München (DE)

 
Remarks:
This application was filed on 14-09-2010 as a divisional application to the application mentioned under INID code 62.
 


(54) Method of cloaking RFID tags


(57) The output (38) to the antenna (42) of an RFID tag or label (10) is disconnected from the balance of the RFID chip by means of a series switch activated in response to a logic command, CLOAK, generated by the RFID chip. Activation of the switch disconnects the output (34) to the antenna of the RFID tag without disconnecting its input (32). The output to the antenna is thus disconnected for a time sufficient to allow the remaining RFID tags in an RF interrogation field to be identified. However, the input of the antenna remains connected and is capable of receiving at any time (28), including during the cloaking period (30) commands which can lift the tag out of cloaking and allow it to then selectively output its signal.