RFID reader with automatic near/far field interrogation mode switching, and related operating methods

• US 8,305,192 B2
• Filed: 11/21/2008
• Issued: 11/06/2012
• Est. Priority Date: 11/21/2008
• Status: Active Grant

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Connolly, Sean, Duron, Mark
• Primary Examiner(s): Wong, Albert
• Assistant Examiner(s): Point, Rufus
• Application Number:
  US12/275,892
• Publication Number:
  US 20100127828A1
• Time in Patent Office: 1,446 Days
• Field of Search: 340/10.1, 340/10.41, 235/462.2
• US Class Current: 340/10.1
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10237 the reader and the record carrier being capable of selectively switching between reader and record carrier appearance, e.g. in near field communication [NFC] devices where the NFC device may function as an RFID reader or as an RFID tag
• CPC Class Codes: G06K 7/10386 the interrogation device being of the portable or hand-handheld type, e.g. incorporated in ubiquitous hand-held devices such as PDA or mobile phone, or in the form of a portable dedicated RFID reader

Abstract

A dual-mode RFID reader is capable of automatically switching from a far-field interrogation mode to a near-field interrogation mode upon the detection of certain operating or handling conditions. The RFID reader includes an RFID radio module configured to support a far-field interrogation mode and a near-field interrogation mode, an antenna arrangement coupled to the RFID radio module, and a mode-switch sensor architecture coupled to the RFID radio module. The mode-switch sensor architecture is configured to detect conditions indicative of near-field interrogation, and the RFID radio module automatically configures itself for operation in the near-field interrogation mode upon detection of such conditions.

Claims

1. A method of operating a mobile RFID reader that operates in a far-field mode for concurrently interrogating a plurality of RFID tags and in a near-field mode for individually interrogating one RFID tag at a time, the method comprising:

capturing image data, with an optical sensor, of an object within an interrogation field of the mobile RFID reader;

processing the image data to detect whether the object is out of focus;

determining that the object is within close proximity to the mobile RFID reader when the image data indicates that the object is out of focus;

automatically configuring the mobile RFID reader for operation in the near-field mode when the image data indicates that the object is out of focus; and

thereafter, interrogating an RFID tag while the mobile RFID reader is in the near-field mode.

2. The method of claim 1, further comprising automatically configuring the mobile RFID reader for operation in the far-field mode after successfully interrogating the RFID tag.

3. A dual-mode RFID reader comprising:

an RFID radio module configured to support a far-field interrogation mode and a near-field interrogation mode;

an antenna arrangement coupled to the RFID radio module and configured to support the far-field interrogation mode and the near-field interrogation mode; and

a mode-switch sensor architecture coupled to the RFID radio module and configured to detect conditions indicative of near-field interrogation;

wherein;

the RFID radio module automatically configures itself for operation in the near-field interrogation mode upon detection of the conditions;

the mode-switch sensor architecture comprises an optical sensor configured to capture image data of an object within an interrogation field of the dual-mode RFID reader, and comprises an image processor that analyzes the image data; and

the RFID radio module automatically configures itself for operation in the near-field interrogation mode when the image processor detects that the object is out of focus and within close proximity to the dual-mode RFID reader.