Method for detecting portable objects and system for carrying out said method

• US 6,972,663 B1
• Filed: 01/31/2000
• Issued: 12/06/2005
• Est. Priority Date: 02/09/1999
• Status: Expired due to Term

• Current Assignee: Gemalto SA (Thales SA)
• Original Assignee: Gemplus (Thales SA)
• Inventors: Porte, Philippe, Messlem, Omar, Praca, Denis
• Primary Examiner(s): Horabik, Michael
• Assistant Examiner(s): AU, SCOTT D
• Application Number:
  US09/890,951
• Time in Patent Office: 2,136 Days
• Field of Search: 340/10.2, 340/10.4, 340/10.41, 340/10.32, 342/445, 342/455, 342/423, 342/434, 343/853, 343/893, 455/10.33
• US Class Current: 340/10.2
• 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 7/10316 using at least one antenna particularly designed for interrogating the wireless record carriers antennas in general H01Q1/22
• CPC Class Codes: G06K 7/10356 using a plurality of antennas, e.g. configurations including means to resolve interference between the plurality of antennas

Abstract

A method for detecting portable objects from a network of N antennae controlled by a centralized management unit. Signals are simultaneously emitted by the management unit to all antennae. Resulting response signals from antennae that have detected a portable object are received by the management unit. Each object thus detected is successively selected from these signals according to a pre-established sequence. The invention applies in particular to access control.

Claims

1. A method of detecting portable objects using a network of N antennae, controlled by a centralized management unit, comprising the following steps:

transmitting signals simultaneously to all the antennae from said management unit,

receiving response signals from the antennae which have detected a portable object respectively at an input port of said management unit that is assigned to each antenna, and adding said signals to form a resulting signal, and

successively selecting each object detected from this resulting signal, according to a pre-established sequence.

2. A detection method according to claim 1, wherein the successive selection of each object is effected by the use of an anti-collision algorithm.

3. A detection method according to claim 1, wherein the reception of the resulting signal includes a step of identifying the origin of the response signals forming said resulting signal.

4. A detection method according to claim 3, wherein the identification of a response signal includes a step of storing the identification of the antenna associated with the input port at which the response signal is received.

5. A detection method according to claim 4, wherein said storing step includes positioning a flip-flop in a logic state and deactivating it when the unit has entered into communication with the portable object detected by the corresponding antenna.

6. A system of detecting portable objects including a network of N antennae associated with transmission/reception means and a centralized management unit, comprising:

transmission means in the management unit that is connected to transmission/reception means of the antennae and that sends signals simultaneously to all the antennae,

reception means in said unit that is connected to said transmission/reception means and that receives response signals from the antennae which have detected a portable object, in the form of distinct signals for each antenna respectively at an input port of said management unit that is assigned to each antenna, and adds said signals to form a resulting signal, and

means for successively selecting each portable object detected according to a pre-established sequence.

7. A detection system according to claim 6, wherein the means for successively selecting each portable object detected in a pre-established sequence includes an anti-collision algorithm.

8. A detection system according to claim 6 wherein the transmission and reception means of the management unit and the transmission/reception means of the antenna are connected in point-to-point mode by connections of the serial transmission type.

9. A detection system according to claim 8, wherein the management unit includes an antenna discriminator.