Detector

• US 20070103307A1
• Filed: 11/13/2006
• Published: 05/10/2007
• Est. Priority Date: 11/21/2002
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Loh, Weng Wah, Dickin, Fraser John, Waters, John
• Granted Patent: US 7,646,303 B2
• Time in Patent Office: Days
• US Class Current: 340/572.500
• CPC Class Codes: G01S 13/753 using frequency selective elements, e.g. resonator
• 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 7/10128 the step consisting of detection of the presence of one or more record carriers in the vicinity of the interrogation device

Abstract

A detector for detecting the presence of a memory tag, the detector comprising a radio frequency source operable to generate a radio frequency signal and a detector resonant circuit part connected to the radio frequency source, the detector resonant circuit part comprising an antenna, the detector further comprising a power monitor responsive to the power of a reflected signal returned from the detector resonant circuit part, the power monitor being operable to generate an output in response to the power of the reflected signal, wherein a decrease in the power of the reflected signal indicates the presence of a tag in the vicinity of the antenna.

Claims

1. A printer operable to print on a base medium provided with at least one memory tag, the printer comprising a detector for detecting the presence of a memory tag, the detector comprising a radio frequency source operable to generate a radio frequency signal and a detector resonant circuit part connected to the radio frequency source, the detector resonant circuit part comprising an antenna,

the detector further comprising a power monitor responsive to the power of a reflected signal returned from the detector resonant circuit part,

the power monitor being operable to generate an output in response to the power of the reflected signal,

wherein a decrease in the power of the reflected signal indicates the presence of a tag in the vicinity of the antenna.

2. A printer according to claim 1 wherein the printer is operable to read data from and/or write data to the tag in response to the power monitor output.

3. A method for detecting the presence of a tag, comprising

transmitting a signal to a resonant circuit part comprising an antenna, monitoring the power of a reflected signal reflected from the resonant circuit part,

wherein a decrease in the power of the reflected signal indicates the presence of a tag in the vicinity of the antenna.