DE102008037376A1 - Lock, in particular lock cylinder with a device for communication with a transponder and communication device - Google Patents

Abstract

The mechanism has a transmission-reception device (2) for sending an activation signal (14) i.e. electromagnetic alternating field, at an operating frequency of a transponder (5) and for receiving a data signal (15) that is sent back from the transponder. An antenna (3) and a sensor antenna (7) are assigned to the transmission-reception device and an inductive sensor circuit (6), respectively. The antennas form a magnetically coupled, galvanically decoupled coil system. The sensor antenna is operated at a frequency corresponding to the operating frequency of the antenna. An independent claim is also included for a lock i.e. lock cylinder, including an actuation member.

Description

The The invention first relates to a device for communication with a transponder on a lock, in particular on a lock cylinder, with a transceiver for transmitting an activation signal in the form of an electromagnetic alternating field at a working frequency of the transponder and to receive a returned from the transponder Data signal and with an evaluation device for evaluating the received data signal and a control device for control the transceiver with an inductive sensor arrangement, which controlled by the controller at predetermined intervals briefly builds up an electromagnetic sensor field, which during the Approaching the transponder is affected, the control device the transceiver only then to send the activation signal controls when the influence of the sensor field a predetermined Threshold exceeds or falls below.

The The invention also relates to a lock, and more particularly a lock cylinder equipped with such a communication device is.

The DE 100 45 631 A1 describes such a lock cylinder. The lock cylinder has a housing in which an electrically actuable locking member and an antenna for receiving an electromagnetic signal for releasing the blocking element is located. The antenna cooperates with a transceiver device, which is energized by a control device at intervals of 5-500 ms, preferably two to four times per second for a short time each. In this case, the antenna builds an electromagnetic alternating field in the vicinity of the lock cylinder, which has a frequency corresponding to the operating frequency of the transponder. The latter is typically 13.56 MHz or 125 kHz. If a transponder is located within this exciter field, then the electromagnetic alternating field inductively couples with the antenna coil of the transponder. There, a voltage is induced, which serves as a power supply for the transponder after a rectification. The transponder has a microchip on which a unique serial number and possibly also data are stored. The microchip receives energy via the coupled-in AC voltage and transmits the serial number or data via its antenna coil. These are received by the antenna coil of the transceiver of the lock cylinder and evaluated by an evaluation device. If the transponder has a serial number which is stored as authorized to close, or if a closing authorization is determined by the evaluation device after evaluation of other data, a blocking or coupling element of the locking cylinder is actuated, so that the closing element can be actuated by the actuating element.

such Lock cylinders are usually battery operated. In the construction of a communication device with the lock cylinder and a transponder is therefore on a minimum total energy intake to pay attention. On the other hand, it must be ensured that the Lock cylinder at any time by approaching a Transponders is unlocked. So it is important that several times per second the environment of the lock cylinder after the presence a transponder is queried. In the prior art you have therefore already suggested the approach of an object to detect with a proximity switch. disadvantageous but the use of a proximity switch but is Sensitivity to any kind of metals, so the Transceiver is already activated even if just a piece of metal or a user's hand Lock cylinder approaches. It comes to a variety of unnecessary send-receive attempts, which is a significant Deprive energy of the battery of the lock cylinder. For example may be an unfavorable arrangement of metal parts in the area a lock cylinder already cause that permanently or every time you open the door from the room inside an activation of the transceiver he follows.

A lock cylinder with a key, in which the locking secret is in a transponder, also describes the DE 10 2005 019 170 A1 ,

Of Further, motor vehicle door handles are known in which an antenna and a sensor arrangement is arranged. In the sensor arrangement it is a capacitive sensor that approximates of a person. Will the approach of a person determined, so a transceiver is in operation taken to a transponder in the manner described above to communicate.

Of the Invention is based on the object, the electrical energy consumption a generic communication device to reduce.

Solved The object is achieved by the specified in claim 1 communication device or the lock specified in claim 14. The dependent claims represent advantageous developments, on the other hand relate but also independent solutions to the task.

First and foremost, an additional inductive sensor arrangement is provided, which is controlled by the control device, in front of given intervals briefly an electromagnetic sensor field builds up, which is influenced when approaching the transponder from its resonant circuit, the control means the transmitter-receiving device only for the transmission of the activation signal drives when the influence of the sensor field exceeds or falls below a predetermined threshold. Two antennas are provided which form a galvanically decoupled and magnetically coupled coil system. The electromagnetic sensor field generating antenna forms a resonant circuit whose frequency is substantially the same with which the transceiver operates. The inductive sensor is of an energy-saving type. It can contain a separate high-frequency circuit. The periodic control of the sensor and the evaluation of the output signal of the sensor is performed by a microprocessor. The detection of a transponder is realized by a threshold value comparison. The transceiver for transmitting the activation signal is only turned on when the approach of a transponder has been detected. The energy for operating the inductive sensor arrangement is considerably lower than the energy required to emit an activation signal by means of the transceiver. The inductive sensor arrangement works together with the resonant circuit of the transponder. Thus, only those transponders are detected whose resonant frequency is close to the operating frequency of the inductive sensor arrangement. An approach of persons or metals is thus not detected. As a result, an erroneous switching on of the transceiver device can be minimized. This also leads to a saving of electrical energy. The sensor field is preferably generated by an antenna coupled to a frequency generator. The antenna may be an induction coil. The antenna coil is acted upon by the frequency generator at intervals, which may be in the range between 5-500 msec, briefly with an alternating voltage. The admission takes place over several hundred oscillation periods. If the working frequency of the transponder is 13.56 MHz, then the pulses have a duration of 10-50 μs. If the operating frequency of the transponder is 125 KHz, the pulses are correspondingly longer and lie between 1 and 5 ms. The transmission power of this antenna is considerably lower than the transmission power of the antenna, which is supplied by the transceiver with voltage. At the antenna of the inductive sensor arrangement, the antenna voltage is tapped. This is preferably done with high impedance. The control device has an analog-to-digital converter, which converts the tapped antenna voltage into a digital value. The control device also has a threshold comparator, which can be designed as a software module. This threshold comparator compares the digitized antenna voltage with an upper and a lower threshold. The upper and lower thresholds form a window. If the antenna voltage lies within the window, this means that there is no transponder near the antenna. If the antenna voltage lies outside this window, ie above the upper threshold value or below the lower threshold value, then it can be assumed that a transponder is located in the reading area of the communication device. In this case, the transceiver is put into operation. It sends the activation signal in the form of an alternating electromagnetic field and receives the returned data from the transponder. If the transponder has locking authorization, a corresponding output signal is provided with which a blocking member or a coupling member can be actuated. The electromagnetic sensor field generating antenna is preferably operated at a frequency which is in the range of the operating frequency of the transponder. It can be a bit bigger or smaller. Due to manufacturing tolerances, the frequencies of the transponder to be detected are not always exactly at 13.56 MHz. The operating frequencies of the transponders of this class can be up to 18 MHz. In this respect, it is sufficient if the frequency of the electromagnetic alternating field of the sensor device is also in this tolerance field. The frequency of the sensor field also does not have to be stabilized. It is not only permissible if the frequency of the sensor field fluctuates or drifts about the operating frequency of the transponder or about the operating frequency of the transceiver. This can even be beneficial. The frequency generator may be an LC resonant circuit. Preferably, however, the frequency generator is formed by an RC element. The communication device may have two antennas. A first antenna is associated with the transceiver and a second antenna of the inductive sensor array. Since both antennas operate at frequencies that are only slightly different from each other, there is a strongly coupled coil system. Despite the parasitic effects of the other coil and the components connected to it, each coil has the desired properties in terms of resonance frequency and field strength. The transmission power of the inductive sensor arrangement needs to be at most 10% of the transmission power of the transceiver device for generating the activation signal. With the inventively designed communication device can average supply currents in the passive phase of the communication device of less than 10 microamps realize. In addition, with the inventive dimensioning of the sensor arrangement, the number of futile transmitting and receiving attempts with a transponder considerably reduced. These currents of 100 milliamps requiring data exchange communication attempts usually take place only when a transponder is actually in close proximity to the antenna array. This, overall low power consumption leads to a longer battery life. It is also advantageous if the sensor coil is a wound air-core coil and has approximately the same number of turns as the read coil formed by a spiral-shaped conductor track. The latter can be arranged at the rear of the sensor coil in a housing. The detection zone is then located in front of the wound air-core coil. The two antenna coils can be arranged coaxially with each other to optimize the magnetic coupling and have a same diameter. It is basically sufficient, however, if the two coils are only partially magnetically coupled.

One Embodiment will be attached below Drawings explained. Show it:

1 a block diagram of the communication device, and

2 roughly schematically a lock cylinder with such a communication device.

The in 2 illustrated shooting cylinder has a cylinder housing with a housing bore in which a cylinder core 22 plugged. The cylinder core 22 can be operated with a handle, such as a key. The cylinder core 22 can also have a knob. The cylinder core 22 is with a closing element 21 coupled. With the closing element 21 a locking mechanism of a lock can be actuated. The lock cylinder 20 is preferably a standard lock cylinder and can be installed in doors. Within the lock cylinder or in a knob is also a battery for power supply.

Within the flange section of the lock cylinder 20 is one with the reference number 23 indicated locking member, which the rotation of the cylinder core 22 can lock. The locking member 23 is electrically operated. In an electrical actuation of the locking member 23 becomes the rotatability of the cylinder core 22 unlocked so that the closing member 21 can be operated by a handle.

Alternatively, the actuator may 22 but also via a coupling member with the closing member 21 be coupled. In the non-actuated state of the electric coupling member then the actuator is not coupled to the closing member. Only when electrical actuation of the coupling member there is a rotationally fixed connection between the closing member 21 and actuator 22 ,

The electrical signal for actuating the locking member or the coupling member provides a communication device, as shown for example in the 1 is shown. With the reference number 11 there is shown the switching output, which is connected to the blocking or coupling member. The reference number 10 indicates the operating voltage supply of a control device 1 at. At the control device 1 it can be a microcontroller. Within the microcontroller there is an evaluation device 4 , a timer 19 , an analog-digital converter 8th and a comparator 9 , The communication device also has a transceiver 2 at the one antenna 3 connected. Furthermore, the communication device has an inductive sensor circuit 6 which also has an antenna 7 connected is. The antenna 3 and the sensor antenna 7 can be formed by coils.

The communication device communicates with a transponder 5 , The transponder 5 may be arranged in the ridge of a key or in a housing in the form of a coin. The transponder 5 has a transponder antenna 12 that with a transponder circuit 13 connected in the form of a microchip. In the transponder circuit 13 is a serial number stored. Optionally, in the transponder circuit 13 also saved more data. The power supply of the transponder 5 is done by inductive coupling of the transponder antenna 12 to an electromagnetic alternating field of 13.56 MHz. The in the transponder antenna 12 Coupled AC voltage is rectified and provides the operating voltage for the transponder circuit 13 , As soon as it is supplied with sufficient energy, it transmits via the transponder antenna 12 on the carrier frequency 13.56 MHz data and in particular the unique serial number.

The aforementioned electromagnetic alternating field for activating the transponder 5 is from the transceiver 2 over the antenna 3 generated. For this purpose, the transceiver receives 2 over with the reference number 14 drawn line an activation signal. The data signal 15 is from an evaluation device formed by the transmitting-receiving device 4 evaluated. If the transponder and in particular its unique serial number has a locking authorization, the switch output is used 11 delivered the switching signal.

To the activation signal 14 only deliver, if with high probability, the transponder in the reception area of the antenna 3 is, is the sensor circuit 6 with associated sensor antenna 7 intended. The one from the controller 1 trained timers 19 delivers at intervals about two to four times per second each for short times (about 10-50 microseconds) a supply voltage 16 for the sensor circuit 6 , The supply voltage 16 delivered so long that about 100-500 amplitudes are sent. The amplitude is about 3 to 10 V (peak-to-peak).

The sensor circuit 6 has a frequency generator 18 which is formed by an RC element. About one or more coupling capacitors and one or more coupling resistors is the frequency generator 18 generated AC voltage in the sensor antenna 7 coupled. The frequency of the frequency generator 18 generated sensor frequency is essentially at the operating frequency of the transponder. It may be slightly above the working frequency or below the operating frequency of the transponder. However, it is essential that a resonance coupling with the antenna 3 the transceiver 2 takes place. This leads to a deliberate weakening of the detection performance of the sensor arrangement and to the fact that the detection area is limited to the area immediately in front of the antenna arrangement.

is If there is no transponder nearby, the antenna voltage is present in a window formed by a lower and an upper threshold.

About a high-impedance resistor 24 becomes the antenna voltage of the sensor antenna 7 decoupled and rectified with an AM demodulation stage. The antenna voltage 17 is in an analog-to-digital converter 8th converted into a digital value. The digital value corresponds to the amplitude of the sensor antenna 7 ,

With the reference number 9 is a comparator referred to, which may be formed in the microcontroller but also by a software module. In the comparator 9 becomes the digital output signal of the analog-to-digital converter 8th compared with a stored lower and a stored upper threshold. If the digital value lies within the window defined by the two threshold values, no transponder is located in the receiving area of the communication device.

Becomes a transponder 5 placed in the receiving area of the communication device, ie in the effective range of the inductive sensor arrangement 6 . 7 , Thus, the electromagnetic alternating field of the inductive sensor array 6 . 7 affected. Because of the quasi-resonance, it may be a field attenuation or a field enhancement. A field attenuation leads to a reduction in the amplitude of the sensor antenna 7 , A field gain leads to an increase of this amplitude. It is usually the geometric properties of the approximated transponder that are responsible for whether it is a voltage reduction or a voltage increase. What is relevant, however, is the resonance coupling, which prevents the mere approach of metal parts or the hand of a user from leading to any significant change in the amplitude. The from the antenna voltage 17 The digital value obtained must therefore lie outside a window in order to output the output signal. Exceeds that of the digital converter 8th If the digital value obtained exceeds the upper threshold value, or if it falls below the lower threshold value, then the comparator outputs 9 an output signal indicative of the delivery of an activation signal 14 from the controller 1 and the receiving device 2 entails. Only now builds the transceiver 2 with the help of the antenna 3 the electromagnetic alternating field on the operating frequency of the transponder 5 on to be inductive with the antenna 12 of the transponder 5 to couple and the transponder circuit 3 to encourage sending data, and in particular the serial number, in the manner described above. The data exchange takes about 50-100 ms. The load is thus more than ten times as high as the load when sending the detection signal.

In an embodiment not shown, the inductive sensor circuit itself but also have a resonant circuit. It may be a self-oscillating resonant circuit by approaching the resonant circuit 12 of the transponder 5 is dampened, amplified or detuned or begins to vibrate or stops swinging. Is the resonant circuit of the sensor circuit 6 detuned, then the sensor output signal 17 instead of an amplitude value, it may also be a frequency value which is converted into a digital value and then compared to threshold values.

Instead of a digital processing of the output signal 17 of the inductive sensor 6 but can also be set an analog circuit.

The supply voltage of the inductive sensor 6 . 7 is also in the previously mentioned embodiments periodically switched on and off by a microprocessor. After switching on the supply voltage, a frequency generator starts 18 with a frequency generation, wherein the success- te frequency is close to the operating frequency of the transponder system. An electromagnetic alternating field is created at the antenna of the inductive sensor. This alternating electromagnetic field is rectified with an AM demodulator. The rectified signal forms the off output signal of the inductive sensor. If no transponder is within range of the antenna, then after a certain settling time of a few hundred periods, a certain voltage level arises as the output voltage. This output voltage corresponds to the idle state when the transponder is not in the field. When the transponder is in the field, the voltage level of the inductive sensor changes. From a certain threshold, it can be safely assumed that a transponder has approached the field of the inductive sensor. Only then is the actual communication with the transponder switched on.

The from the sensor antenna 7 generated field strengths are significantly lower than those of the antenna 3 established field strengths.

All disclosed features are essential to the invention (in itself). In the disclosure of the application is hereby also the disclosure content the associated / attached priority documents (Copy of the advance notice) fully included, too for the purpose, features of these documents in claims present Registration with.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 10045631 A1 [0003]
• - DE 102005019170 A1 [0005]

Claims (14)

Device for communication with a transponder ( 5 ) on a lock, in particular on a lock cylinder, with a transceiver device ( 2 ) for transmitting an activation signal ( 14 ) in the form of an alternating electromagnetic field at an operating frequency of the transponder ( 5 ) and to receive one from the transponder ( 5 ) returned data signal ( 15 ) and with an evaluation device ( 4 ) for evaluating the received data signal ( 15 ) and a control device ( 1 ) for controlling the transceiver device ( 2 ), with an inductive sensor arrangement ( 6 . 7 ), which is controlled by the control device ( 1 ) controlled at predetermined intervals a short time an electromagnetic sensor field builds up, which when approaching the transponder ( 5 ), the control device ( 1 ) the transceiver ( 2 ) only then to send the activation signal ( 14 ), if the influencing of the sensor field exceeds or falls below a predefined threshold value, characterized by two antennas ( 3 . 7 ), wherein a first antenna ( 3 ) of the transceiver device ( 2 ) and a second antenna ( 7 ) is associated with the inductive sensor arrangement, wherein the two antennas form a magnetically coupled, but galvanically decoupled coil system and the second antenna ( 7 ) is operated at a frequency substantially equal to the operating frequency of the first antenna ( 3 ) corresponds. Communication device according to claim 1 or in particular according thereto, characterized in that the sensor field from a to a frequency generator ( 18 ) coupled antenna ( 7 ) is generated, one at the antenna ( 7 ) tapped voltage ( 17 ) is compared with the threshold. Communication device according to one or more of the preceding claims or in particular according thereto, characterized in that the sensor field at intervals of eg. about 5-500 ms is generated. Communication device according to one or more of the preceding claims or in particular according thereto, characterized in that the sensor field at an operating frequency of a transponder of 13.56 MHz for about 10-50 μs and in a transponder ( 5 ) is generated at an operating frequency of 125 kHz for about 1 ms to 5 ms. Communication device according to one or more of the preceding claims or in particular according thereto, characterized in that the sensor antenna ( 7 ) driving frequency generator ( 18 ) is an RC generator. Communication device according to one or more of the preceding claims or in particular according thereto, characterized in that the antenna generating the electromagnetic sensor field ( 7 ) is operated at a frequency substantially equal to the operating frequency of the transponder ( 5 ) corresponds. Communication device according to one or more of the preceding claims or in particular according thereto, characterized in that the two antennas ( 3 . 7 ) are coaxially arranged coils with substantially the same coil area. Communication device according to one or more of the preceding claims or in particular according thereto, characterized in that the second antenna ( 7 ) is formed by a wound air-core coil which is connected between the first antenna ( 3 ) and the detection zone is arranged. Communication device according to one or more of the preceding claims or in particular according thereto, characterized in that the first antenna ( 3 ) is formed by a printed circuit trace and has approximately the same number of turns as the second antenna ( 7 ). Communication device according to one or more of the preceding claims or in particular according thereto, characterized in that that at the second antenna ( 7 ) tapped voltage ( 17 ) is compared with an upper and a lower threshold value and the control device ( 1 ) the transceiver ( 2 ) for the transmission of the activation signal ( 14 ), if either the upper threshold value is exceeded or the lower threshold value is undershot. Communication device according to one or more of the preceding claims or in particular according thereto, characterized in that the antenna ( 7 ) of the inductive sensor arrangement with high impedance to an analog-to-digital converter ( 8th ) is coupled. Communication device according to one or more of the preceding claims or in particular according thereto, characterized in that the decoupled antenna voltage ( 17 ) of the inductive sensor arrangement is compared in the form of digital values with an upper and a lower threshold value, and the activation signal is only generated if the lower threshold value is exceeded or the upper threshold value is exceeded. Communication device according to one or more of the preceding claims or in special according thereto, characterized in that the transmission power of the inductive sensor arrangement ( 6 . 7 ) at most 10% of the transmission power of the transceiver ( 2 ) is for generating the activation signal. Lock, in particular lock cylinder ( 20 ) with a closing member ( 21 ) and an actuator ( 22 ) and with an electrically actuable blocking or coupling member ( 23 ), wherein the closing member ( 21 ) only after approximation of a transponder returning a suitable data signal ( 5 ) of the actuator ( 22 ), characterized by a communication device according to one of the preceding claims.