Access control system

• US 20090051483A1
• Filed: 08/08/2007
• Published: 02/26/2009
• Est. Priority Date: 08/08/2006
• Status: Active Grant

• Current Assignee: SKIDATA AG (Thales SA)
• Original Assignee: SKIDATA AG (Thales SA)
• Inventors: Ponert, Gregor, Golser, Rudolf
• Granted Patent: US 8,138,884 B2
• Time in Patent Office: Days
• US Class Current: 340/5.700
• 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: G07C 9/10 Movable barriers with registering means
• CPC Class Codes: G07C 9/15 with arrangements to prevent the passage of more than one individual at a time
• CPC Class Codes: G07C 9/28 the pass enabling tracking or indicating presence
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 7/005 with variable reactance for tuning the antenna

Abstract

An access control system has at least two antenna coils (12, 13 and 14, 15) arranged one behind the other at an entrance lane (4) and connected to a reading device (20), which with a capacitance (40, 41) form an oscillating circuit (30, 31). Here either the one oscillating circuit (30, 31) with the in entrance direction (5) first antenna coil (12, 13) or the other oscillating circuit with the second antenna coil (14, 15) is actuated by the reading device (20), in order to read out data for the purpose of access authorization from a transponder (22) which is carried by a user and has a transponder coil (24) coupleable with the antenna coils (12 to 15). The oscillating circuit (30, 31) not actuated by the reading device (20) is detuned or short-circuited.

Claims

1. An access control system with at least two antenna coils (12, 13 and 14, 15) arranged one behind the other at an entrance lane (4) and connected to a reading device (20), which with a capacitance (39, 41) form an oscillating circuit (30, 31), wherein either the one oscillating circuit (30, 31) is actuated with the in entrance direction (5) first antenna coil (12, 13) or the other oscillating circuit is actuated with the second antenna coil (14, 15) by the reading device (20), in order to read out data for the purpose of access authorization from a transponder (22) which is carried by a user and has a transponder coil (24) coupleable with the antenna coils (12 to 15), characterized in that the not actuated oscillating circuit (30, 31) is detuned or short-circuited with the help of a detuning or short-circuiting electronics (52, 53), for the power supply and as a switch signal for the detuning or short-circuiting electronics (52, 53), a low-voltage DC voltage being used, which is drawn from the power supply of the reading device and the cables (16 to 19), which connect the reading device (20) with the oscillating circuits (30, 31) with the antenna coils (12 to 15), at the same time being provided for the power supply and for transmitting the switch signals for the detuning or short-circuiting electronics (52, 53).

2. The access control system according to claim 1, characterized in that a blocking system is provided, which in its basic position releases the entrance (4) and only blocks upon an invalid reading of an access authorization and detection of a person by a people sensor (23), wherein the blocking element can be actuated by the reading device (20) in dependence on a valid or invalid reading of an access authorization effected with the first antenna coil (12, 13) or the second antenna coil (14, 15).

3. The access control system according to claim 1, characterized in that opposite the first and/or the second antenna coil (12, 14) there is provided an antenna coil (13, 15) on the other side of the entrance lane (4) for forming a second oscillating circuit, wherein the mutually opposing antenna coils (12, 13 and 14, 15) form an antenna coil pair, the antenna coils (12, 13 or 14, 15) of each pair are actuated at the same time by the reading device (20), but alternately in an in-phase or in an antiphase operation mode, and for reading out the transponder (22) carried by the user the one operation mode with which the transponder (22) is detected is maintained until the reading transaction is completed.

4. The access control system according to claim 1, characterized in that the detuning or short-circuiting electronics (52, 53) has at least one diode switch.

5. The access control system according to claim 1, characterized in that the detuning or short-circuiting electronics is preceded by a decoupling unit for decoupling the alternating voltage of the oscillating circuit (30, 31).

6. The access control system according to claim 5, characterized in that the decoupling unit is formed by a coil (54, 55).

7. The access control system according to claim 1, characterized in that for actuating the detuning or short-circuiting electronics (52, 53) of the oscillating circuits (30, 31) a switch (58) is used.