Read-write processing apparatus and method for RFID tag

• US 20050170784A1
• Filed: 01/21/2005
• Published: 08/04/2005
• Est. Priority Date: 01/27/2004
• Status: Active Grant

• Current Assignee: Omron Corporation
• Original Assignee: Omron Corporation
• Inventors: Ozaki, Koyo, Sakacho, Koji, Ariyoshi, Tomonori
• Granted Patent: US 7,421,249 B2
• Time in Patent Office: Days
• US Class Current: 455/67.130
• 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: H01Q 1/362 for broadside radiating helical antennas
• CPC Class Codes: H01Q 11/08 Helical antennas
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H04B 5/00 Near-field transmission systems, e.g. inductive or capacitive transmission systems
• CPC Class Codes: H04B 5/0056 for use in interrogation, identification or read/write systems record carriers G06K7/00, G06K19/00; for railways B61L3/12
• CPC Class Codes: H04B 5/0062 in RFID [Radio Frequency Identification] Systems
• CPC Class Codes: H04B 5/0081 with antenna coils loop aerials H01Q7/00
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/77 for interrogation

Abstract

A read-write processing apparatus communicates with an RFID tag provided with a semiconductor memory to exchange commands and responses through antenna coils. A condition under which only a carrier wave is transmitted is set prior to a communication with the RFID tag and a level from a reception signal obtained under this condition is extracted as noise level. The extracted noise level is displayed or outputted to an output host apparatus.

Claims

1. An apparatus for communicating with an RFID tag provided with a semiconductor memory to read and write data from and into said semiconductor memory, said apparatus comprising:

wait condition setting means for setting a wait condition prior to a communication with said RFID tag, only a carrier wave being transmitted under said wait condition;

noise level extracting means for extracting as noise level a level from a reception signal obtained under said wait condition; and

reporting means for displaying or outputting said extracted noise level.

2. The apparatus of claim 1 further comprising:

history data memory that stores history data on processes of each time; and

storing means for storing said extracted noise level in said history data memory in correlation with data that indicate success and failure of communication with said RFID tag.

3. An apparatus for communicating with an RFID tag provided with a semiconductor memory to read and write data from and into said semiconductor memory, said apparatus comprising:

signal extracting means for extracting level of a data signal and level of a base signal from a signal being received in a communication process with said RFID tag, said data signal and said base signal respectively corresponding to a period during which said RFID tag switches and does not switch impedance periodically;

calculating means for calculating the ratio or the difference between the levels of said data signal and said base signal; and

reporting means for displaying or outputting result of calculation by said calculating means.

4. The apparatus of claim 3 further comprising communication control means for comparing a numerical value obtained by said calculating means with a specified threshold value and stopping said communication process when said numerical value changes so as to cross said threshold value.

5. The apparatus of claim 3 further comprising:

history data memory that stores history data on processes of each time; and

storing means for storing the result of calculation by said calculating means in said history data memory in correlation with data that indicate success and failure of communication with said RFID tag.

6. The apparatus of claim 4 further comprising:

history data memory that stores history data on processes of each time; and

storing means for storing the result of calculation by said calculating means in said history data memory in correlation with data that indicate success and failure of communication with said RFID tag.

7. An apparatus for communicating with an RFID tag provided with a semiconductor memory to read and write data from and into said semiconductor memory, said apparatus comprising:

wait condition setting means for setting a wait condition prior to a communication with said RFID tag, only a carrier wave being transmitted under said wait condition;

noise level extracting means for extracting as noise level a level from a reception signal obtained under said wait condition; and

communication control means for discontinuing said wait condition and starting a communication with said RFID tag after a condition in which said noise level remains smaller than a specified value has continued for a specified length of time.

8. A method of communicating with an RFID tag provided with a semiconductor memory to read and write data from and into said semiconductor memory, said method comprising the steps of:

setting a wait condition prior to a communication with said RFID tag, only a carrier wave being transmitted under said wait condition;

extracting as noise level a level from a reception signal obtained under said wait condition; and

displaying or outputting said extracted noise level.

9. A method of communicating with an RFID tag provided with a semiconductor memory to read and write data from and into said semiconductor memory, said method comprising the steps of:

extracting level of a data signal and level of a base signal from a signal being received in a communication process with said RFID tag, said data signal and said base signal respectively corresponding to a period during which said RFID tag switches and does not switch impedance periodically;

calculating the ratio or the difference between the levels of said data signal and said base signal; and

displaying or outputting result of calculation by said calculating means.