Method of reading a plurality of non-contact data carriers, including an anti-collision scheme

• US 20060031546A1
• Filed: 08/29/2003
• Published: 02/09/2006
• Est. Priority Date: 09/11/2002
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Thueringer, Peter, Breitfuss, Klemens
• Granted Patent: US 8,203,432 B2
• Time in Patent Office: Days
• US Class Current: 709/231
• 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 7/10029 the collision being resolved in the time domain, e.g. using binary tree search or RFID responses allocated to a random time slot
• CPC Class Codes: G06K 7/10059 transponder driven

Abstract

A method of inventorying data carriers (2) by means of a communication station, whereby the communication station and each data carrier (2) are brought into communicative connection, and each data carrier (2) brought into communicative connection with the communication station is capable of generating a response signal (IDS) that renders possible an inventorying of the data carrier and is capable of delivering a generated response signal (IDS) with the use of a transmission start moment that can be selected from a plurality of transmission start moments (t5, t6), each data carrier tests whether another data carrier (2) is already giving its response signal (IDS). Each data carrier (2) subsequently discontinues the generation or delivery of its response signal (IDS) if another data carrier (2) is already providing its response signal (IDS).

Claims

1. A method of inventorying data carriers by means of a communication station,

wherein said communication station and each data carrier are brought into communicative connection, and

wherein each data carrier brought into communicative connection with the communication station generates a response signal enabling the inventorying of the data carrier after at least one operational condition has been fulfilled and supplies said response signal using a transmission start moment that can be chosen from a plurality of transmission start moments, and

wherein each data carrier before providing its response signal tests whether another data carrier is already providing its response signal, and

wherein each data carrier discontinues the provision of its response signal if another data carrier is already giving its response signal.

2. A method as claimed in claim 1,

wherein each data carrier already before generating its response signal tests whether another data carrier is giving its response signal, and

wherein each data carrier discontinues the generation of its response signal if another data carrier is already giving its response signal.

3. A method as claimed in claim 1, wherein the response signal given is an identification signal.

4. A method as claimed in claim 1, wherein the transmission start moment is selected by a random principle.

5. A method as claimed in claim 1, wherein the selected transmission start moment is shifted in time by a selectable discrete delay period with respect to a command signal end of a command signal given by the communication station.

6. A method as claimed in claim 1, wherein the number of selectable transmission start moments is greater than the number of data carriers.

7. A method as claimed in claim 1, wherein a data carrier that has given a response signal can be set to an idle state by the communication station, in which idle state no response signal is provided.

8. A data carrier, which data carrier is designed for contactless communication with a communication station and which comprises an integrated circuit, which integrated circuit comprises the following means:

response signal generation means for generating a response signal start moment selection means by which a transmission start moment can be selected from a plurality of transmission start moments and response signal recognition means designed for recognizing a response signal given by another data carrier and for generating and delivering a response signal recognition signal and wherein delivery decision means are provided which release or block a delivery of the response signal in dependence on the response signal recognition signal and the transmission start moment.

9. A data carrier as claimed in claim 8, wherein the response signal generation means are formed by identification signal generation means.

10. A data carrier as claimed in claim 8 or 9, wherein the response signal recognition means are designed for recognizing a carrier signal.

11. A data carrier as claimed in claim 8, wherein the response signal recognition means are designed for recognizing a modulated carrier signal and for this purpose comprise demodulation means which are designed for demodulating a modulated carrier signal.

12. An integrated circuit for a data carrier which data carrier is designed for contactless communication with a communication station, said integrated circuit comprising the following means:

response signal generation means for generating a response signal start moment selection means by which a transmission start moment can be selected from a plurality of transmission start moments and response signal recognition means designed for recognizing a response signal given by another data carrier and for generating and delivering a response signal recognition signal and wherein delivery decision means are provided which release or block a delivery of the response signal in dependence on the response signal recognition signal and the transmission start moment.

13. An integrated circuit as claimed in claim 12, wherein the response signal generation means are formed by identification signal generation means.

14. An integrated circuit as claimed in claim 12, wherein the response signal recognition means are designed for recognizing a carrier signal.

15. An integrated circuit as claimed in claim 12, wherein the response signal recognition means are designed for recognizing a modulated carrier signal and for this purpose comprise demodulation means which are designed for demodulating a modulated carrier signal.