Patent ID: 8138884
Filing Date: 2012-03-20
Classification: G06K,G07C,H01Q

Abstract:
1. An access control system comprising: a reading device having a power supply; first and second pairs of mutually opposing antenna coils wherein said antenna coils of said first and second antenna coil pairs are provided on opposite sides of an entrance lane, said first and second antenna coil pairs being arranged one behind the other at the entrance lane so that said first antenna coil pair is passed first by a user moving through said entrance lane, and said second antenna coil pair is passed thereafter by the user; said antenna coils of said first and second antenna coil pairs being connected to the reading device by respective cables, and being provided with a capacitance to each form a respective oscillating circuit, said antenna coils being provided for detecting access authorization by reading out data from a transponder, which is carried by said user and has a transponder coil couplable with the antenna coils, wherein either the oscillating circuits associated with the first antenna coil pair are actuated by said reading device during a reading transaction while said oscillating circuits of said second antenna coil pair are deactivated, or the oscillating circuits associated with the second antenna coil pair are actuated by the reading device during the reading transaction while said oscillating circuits of said first antenna coil pair are deactivated; detuning or short-circuiting electronics being provided respectively for each of the oscillating circuits of said first antenna coil pair and said second antenna coil pair wherein the detuning or short-circuiting electronics are switchable by a switch signal to detune or short-circuit the oscillating circuits such that the oscillating circuits of either said first antenna coil pair or said second antenna coil pair when deactivated are detuned or short-circuited by the detuning or short-circuiting electronics, a low-voltage DC voltage being used as a power supply and as the switch signal for the detuning or short-circuiting electronics to detune or short-circuit either said first antenna coil pair or said second antenna coil pair when deactivated, which said low-voltage DC voltage is drawn from the power supply of the reading device; wherein the cables, which connect the reading device with the oscillating circuits of the first and second antenna coil pairs, at the same time being provided for supplying power from the power supply to the detuning or short-circuiting electronics of the oscillating circuits of the first and second antenna coil pairs and for transmitting the switch signals for the detuning or short-circuiting electronics; a blocking system which releases the entrance lane in a basic position and blocks the entrance lane upon an invalid reading of the access authorization by said first antenna coil pair and detection of a person by a people sensor, said blocking system releasing said entrance lane again upon a valid reading of the access authorization by said second antenna coil pair, wherein the blocking system can be actuated by the reading device in dependence on a valid or invalid reading of an access authorization effected with said first antenna coil pair or said second antenna coil pair; each of said mutually opposing antenna coils of said first antenna coil pair when actuated, and each of said mutually opposing antenna coils of said second antenna coil pair when actuated, being actuated at the same time by the reading device, but alternately in an in-phase or in an antiphase operation mode, wherein the one operation mode with which the transponder is detected is maintained for reading out the transponder carried by the user until the reading transaction is completed; wherein when an invalid access authorization is read by said first antenna coil pair and the user is detected by the people sensor, the antenna coils of said first antenna coil pair are deactivated by said detuning or short circuiting electronics and when thereafter a valid access authorization is read by said antenna coils of said second antenna coil pair, said first antenna coil pair is actuated again.