KR19990039311A - Proximity Switching Card and Anti-theft Device for Car Audio - Google Patents

Abstract

The present invention relates to a proximity switching card and an anti-theft device for a car audio using the same, comprising an IC including a plurality of detectors connected in parallel with the coil and having a coil having a predetermined turn and Henry outside the card. At the same time, the inside of the audio is a microcomputer including a counting circuit and a comparison circuit, a voltage controlled oscillator for oscillating ultra-high frequency of a specific frequency according to the counting signal of the microcomputer, and an output signal of the voltage controlled oscillator is transmitted through the transmitter. Darlington circuit unit for measuring the electric field strength by receiving the received signal and the output signal of the electric field strength measuring unit and judging the output signal of the electric field strength measurement unit and comparing it with the data already stored in memory By doing so, the car audio is operated only when the mobile card is carried, thereby preventing theft of the car audio. It can be easily prevented.

Description

Proximity Switching Card and Anti-theft Device for Car Audio

The present invention relates to a proximity switching card and an anti-theft device of a car audio using the same, and more particularly, to determine whether the proximity switching card and the audio are approached from a transceiver mounted inside the car audio to turn on / off the power of the car audio. By turning it off, the car audio is operated only when the proximity switching card is in close proximity, so that theft of the card audio can be prevented more easily due to easy carrying of the card, and to the anti-theft device of the car audio using the same. It is about.

In general, car audio, which has been recently developed, is configured to separate the front panel with various operation buttons from the main body as shown in FIG. 1 so that the driver can separate and carry the front panel from the car audio main body after parking. Thus, to prevent theft of the car audio, and as an example of the front panel detachable car audio, conventionally, it is provided on the rear of the escalation 71 for accommodating the front panel 70 of the car audio as shown in FIG. A hook assembly 72 for supporting the front panel 70, an elastic member 73 for easy separation of the front panel 70 by protruding to the outside by elasticity, and the front panel 70 It consists of a hinge member (74) for supporting one side upper and lower ends.

In addition, a fixing hole 71a is formed on the inner wall surface of the escalation 71, and a fitting protrusion 70a is formed at one side of the front panel 70 to be inserted into the fixing hole 71a. As the fitting groove 70b is formed on the upper and lower sides of the protrusion 70a to be supported by the hinge member 74, the other side of the fitting groove 70b is provided with a locking groove 70c for assembling the hook assembly 72. ) Is provided.

In addition, an eject knob 75 is elastically installed on one side of the front of the escalation 71 to release the front panel 70 by pressing the hook assembly 72. The hinge member 74 is formed in a U shape. The upper and lower ends are projected by fitting at the rear part of the escalation 71 and fixedly installed by screws at the rear side, and at the same time, the upper and lower ends are guided and supported by the fitting grooves 70b of the front panel 70. The support protrusion 74a for fixing is fixed.

In addition, a spring, not shown, is installed inside the elastic member 73 so as to push the rear surface of the front panel 70 when the front panel 70 is removed from the escalation 71. The hook assembly 72 has a pivot shaft 72a protruding perpendicularly to the upper and lower surfaces, and the pivot shaft 72a is formed in a fixing groove of a rib, not shown, formed on one side of the interior of the escalation 71. The hook 72b is rotatably fitted to each other, and a hook 72b extends on one side of the body, and a torsion spring 72c is provided between the hook assembly 72 and the escalation 71.

In order to mount the front panel 70 of the conventional car audio configured as described above, the fitting protrusion 70a formed on one side of the front panel 70 is first inserted into the fixing hole 71a of the escalation 71, but the front panel When the 70 is inclined at a predetermined angle to be guided by the fixing hole 71a, the front panel 70 is pivoted to closely contact the front of the escalation 70 and pressurized at the same time. The fitting groove 70b is fitted to the support protrusion 74a attached to both ends of the hinge member 74, and the hook assembly 72 provided at the front portion of the escalation 71 is momentarily resilient of the torsion spring 72c. At the same time as receiving the hook (72b) is caught in the engaging groove (70c) formed on the side of the front panel 70 to support the front panel (70).

On the other hand, the elastic member 73 provided on the front of the escalation 71 in a state where the front panel 70 is mounted, the front panel 70 in a state in which the front panel 70 is in close contact with a predetermined area and pressed. Support relative to the hook assembly 72. This is a state in which the front panel 70 is mounted on the escalation 71, and the connection terminals (not shown) are connected so that a plurality of operation knobs installed on the front panel 70 can be pressed to operate the car audio. will be.

In addition, to remove the front panel 70 from the car audio escalation 71, press the eject knob 75 provided on one side of the front of the escalation 71 to pressurize, the eject knob 75 is a hook assembly ( Since the hook assembly 72 is rotated about the pivot shaft 72a by pressing a portion of the 72, the torsion spring 72c is pressed and the hook 72b is engaged with the locking groove 70c of the front panel 70. Depart from

Accordingly, the elastic member 73 installed in the escalation 71 in a linking operation thereof pushes the front panel 70 outward so that the front panel 70 is centered on the support protrusion 74a of the hinge member 73. By sharply rotating and moving to a position where the separation is easy, the user grasps the front panel 70 and separates the fitting protrusion 70a of the front panel 70 from the fixing hole 71a of the escalation 71 so that the front can be separated. The panel 70 is to be completely separated to be portable.

As described above, the front panel is detached from the escalation, and thus, when the car audio is not used, the front panel must be removed and carried. If the front panel is lost, you will not be able to use the car audio.

The present invention has been made to solve the above problems, the user is to set the password inside the card for easy portability of the user, and implements a predetermined circuit to scan the password inside the card inside the car audio Accordingly, an object of the present invention is to provide a proximity switching card and a car audio anti-theft device using the same so that the car audio is operated only when the user carries the card.

In order to solve the above object, the present invention is provided with a coil having a predetermined turn and Henry on the outside of a card, and having an IC including a plurality of detectors connected in parallel with the coil, and inside the car audio. Is a microcomputer provided with a counting circuit and a comparison circuit, a voltage controlled oscillator for oscillating an ultra-short wave of a specific frequency in accordance with the counting signal of the microcomputer, and an output signal of the voltage controlled oscillator transmitted through the transmitter for electric field strength And a Darlington circuit unit for judging the output signal of the field strength measurement unit and comparing the data with the data already stored, and switching the driving of the car audio according to the result.

1 is an exploded perspective view showing a conventional anti-theft car audio,

2 is an overall perspective view showing the operation of the present invention,

3 is a circuit diagram showing the principle of the card used in the present invention,

4 is an overall block diagram of a transceiver unit used in the present invention.

<Explanation of symbols for main parts of drawing>

1: car audio 2: transceiver

3: mobile card 4: IC

5: coil 6,7,8,9: 1st detector-4th detector

C1, C2, C3, C4, C ': Capacitor 10: Transmitter

11 voltage control oscillator 12 die conversion unit

13: microcomputer 14: receiver

15: electric field strength measuring unit 16: AD conversion unit

17: memory 18: backup power

19: car audio drive unit 20: Darlington circuit unit

Referring to the present invention in detail based on the accompanying drawings as follows.

First, Figure 2 is a perspective view showing the operation of the present invention, the front panel of the car audio (1) is located on one side of the transmission and reception unit (2) for transmitting a microwave at a predetermined frequency and detecting the received signal, the transmission frequency The portable cards 3 for synchronization are paired.

The portable card 3 has a coil 5 of a predetermined turn wound around the inner inner rim, and an IC 4 for receiving an electrical signal is transferred into the portable card 3 through the coil 5. It is provided.

Therefore, when the corresponding operation is explained from the above configuration, first, when the user approaches the portable card 3 near the transmitting and receiving unit 2, the radio frequency is transmitted from the backup power source of the car audio 1 by frequency. . That is, a plurality of frequencies already set in the band of the microwave is sequentially transmitted. Then, the password set in the IC 4 is scanned from this transmission frequency, which is a tuning in which the frequency of the microwaves output from the transceiver 2 is transmitted through a predetermined circuit inside the coil 5 and the IC 4. The state is determined, and the received electric field strength reflected by the portable card 3 is measured to the receiving side of the transmitting and receiving unit 2 according to the tuning.

Next, the above operation will be described in more detail with reference to FIG. 3.

First, the coil 5 and the IC 4 are engaged with each other, and inside the IC 4, the first detector 6 and the second detector 7 connected in parallel with each of the coils 5 described above. ) And a third detector 8 and a fourth detector 9, each of which has capacitors C1, C2, C3 and C4 of different capacities, and a fourth detector ( Except for 9), the capacitors C 'of predetermined values are connected in series to the capacitors C1, C2 and C3 of the remaining detector.

The remaining detectors 7, 8, and 9 except for the first detector 6 can always output the tuning signal of the corresponding detector only by tuning to the frequency received from the detector at the front end. The detectors 6, 7, 8, and 9 are composed of daisy chains.

On the other hand, the effect of the above configuration is that the tuning circuit is connected to each of the detectors 6, 7, 8, and 9 connected in parallel with the coil 5 as the plurality of different microwave frequencies described above are sequentially emitted. It is implemented. For example, when the first capacitor C1 of the first detector 6 is synchronized with a specific input frequency from the coil 5, the first detector 6 is the second detector 7. It is to output the ENABLE signal. In synchronization with the second capacitor C2 of the second detector 7 from the subsequent multiple frequency transmissions, the enable signal is output to the third detector 8 as described above, thereby sequentially turning on the daisy chain. To be linked.

Accordingly, subsequent turn-on of each of the detectors 6, 7, 8, and 9 results in lowering the impedance of the tuning circuit. This will be described based on the set value and the equation.

L = 1 μH C ′ = 1 nF

C1 = 25pF C2 = 1pF

C3 = 100 pF C4 = 0.01 pF

Therefore, the tuning frequency of the first detector 6 is 1/10 pi (GHz), and the tuning frequency of the second detector 7 is 1/2 pi (GHz). Subsequently, the tuning frequencies of the third and fourth detectors 9 are 1/20 pi (GHz) and 1 / 0.2 pi (GHz), respectively, since these tuning frequencies are included in the plurality of transmission frequencies described above. In the continuous transmission process of the transceiver 2, the first detector 6 turns on all of the fourth detector 9.

And the impedance is varied from the individual turn-on process of each of these detectors 6, 7, 8, and 9, and this impedance is described by the following equation from the tuning frequency.

Here, X _R is an impedance generated when the tuned frequency is output through C ′. When the tuned frequency is 1/10 pi GHz as in the first detector 6, an impedance of 5Ω is generated by C ′ which is 1 nF. If the second detector 7 is 1 / 2πGHz, the impedance of 1Ω and the third detector 8 and the fourth detector 9 output 10Ω and 0.2Ω, respectively.

This impedance is much different from when it is not tuned by the coil 5 and the capacitor, because the energy of the microwave is converted into electrical energy by tuning.

Therefore, whether or not the frequency transmitted from the transmitting side is tuned can be known from the electric field strength of the reflected frequency. In other words, if the frequency sent by the transmitting side is not tuned, the receiving field strength of the receiving side will be improved, and conversely, if the transmitting frequency is tuned near the receiver, the receiving field strength flowing into the receiver is reduced.

From this, the transmitting side transmits a plurality of different microwaves sequentially, and the receiving side can detect the tuning frequency by detecting it. The receiving number according to the tuning frequency, i.e., a password, is received by having the serial number of the plurality of microwaves. You can do it.

And the tuning frequency of the portable card 3 and the transmission frequency of the car audio 1 are already set at the time of production so that mutual data can be compatible.

Then, the configuration and operation according to the password received in more detail based on Figure 4 as follows.

First, in a state where power is not applied to the car audio driver 19, a backup power source 18 directly supplied with power from a battery to perform a transmission / reception function is connected to the system.

Then, the power is supplied from the backup power source 18 to perform batch processing and comparative output of the input / output of data to be used for transmission and reception, and the output data of the microcomputer 13 provided with the counting circuit is the microcomputer 13. A control voltage is introduced into a voltage control oscillator (VCO: VOLTAGE CONTROL OSCILLATOR: 11) through a die conversion unit 12 that converts the digitized signal into an analog signal. The voltage controlled oscillator 11 then oscillates the frequency according to the input voltage applied thereto, which is transmitted through the transmitter 10 as a microwave.

In addition, the frequency transmitted from the transmission unit 10, the electric field strength measuring unit 15 to measure the electric field strength of the reception frequency as received through the receiving unit 14, which is to output a predetermined electrical signal, This output signal is digitized via the AD converter 16. The digitized signal is then applied to the microcomputer 13 to be compared with the data already stored in the memory unit 17, and according to the comparison result, the power supply to the car audio driver 19 is decided. And switching according to this power supply is configured to be made through the Darlington circuit unit 20.

Next, the operation of the configuration will be described. First, the microcomputer 13 counts data to transmit the plurality of frequencies described above. For example, binary data from 0 to 9 are sequentially output so as to be converted into a linear voltage signal by the die conversion unit 12.

In this case, it is assumed that the microcomputer 13 outputs data corresponding to 1, and the linear voltage generated therefrom is output to the voltage controlled oscillator 11 so that the frequency corresponding to the linear voltage is output. This is sent by the transmitter 10. Therefore, the microwave having this constant frequency is transmitted to the portable card 3 so as to be received through the receiving unit 14. If the first detector 6 of this mobile card 3 is in tune with the currently transmitted frequency, the strength of the frequency induced by the receiver 14 will be weakened, which means that the electric field strength measurer 15 The reference value is measured by.

On the other hand, if the capacity of the first capacitor C1 is set incorrectly so that the portable card 3 does not synchronize with the currently transmitted frequency, the electric field induced by the receiver 14 is applied more strongly. The output voltage of the measuring unit 15 is high. Since the voltage passes through the AD conversion unit 16, the digitized signal is applied to the microcomputer 13, and the microcomputer 13 determines that the first password is not 1 from this.

Then, the microcomputer 13 outputs binary data corresponding to two to the die conversion unit 12 so that the microwave frequency corresponding to the binary data is transmitted to the mobile card 3, and the electric field strength is measured. The unit 15 determines whether the first detector 6 is in sync.

At this time, if the tuning frequency produced by the first capacitor C1 and the coil 5 of the first detector 6 coincides with the transmission frequency, that is, the microwave frequency corresponding to 2, the electric field strength through the receiver 14 The signal flowing into the measuring unit 15 becomes a weak electric power, which is eventually applied as the digitized data to the microcomputer 13 through the AD converter 16.

Due to this, the microcomputer 13 determines that the tuning frequency of the first detection unit 6, that is, the first password is 2, and transmits it to the memory unit 17 for storage. The first detector 6 provided in the IC 4 of the mobile card 3 outputs the enable signal to the second detector 7 because it is tuned by the transmission frequency. Thus, the second detector 7 is ready to receive a specific frequency.

At the same time, the microcomputer 13 starts counting from the beginning again. For example, if the tuning frequency of the second detector 7 matches the ultra-high frequency corresponding to the seventh output data of the microcomputer 13, the microcomputer Up to the sixth output data of (13), the received electric field applied to the electric field strength measuring unit 15 via the receiving unit 14 is in a strong state, which is transmitted to the microcomputer 13 through the AD converter 16. This microcomputer 13 continues to count as it is transmitted.

Therefore, the seventh output data of the microcomputer 13, that is, the binary data corresponding to 6, outputs the corresponding microwave frequency by the voltage controlled oscillator 11 through the die conversion unit 12, which is transmitted to the transmitter 10. By the mobile card (3).

At this time, the second detector 7 is tuned by a specific frequency transmission, and as the received electric field of the receiver 14 weakens, the output value of the electric field strength measuring unit 15 is formed at a low voltage. The low voltage is converted into a digital signal by the AD converter 16 and transmitted to the microcomputer 13, so that the microcomputer 13 currently outputs the second password of the mobile card 3. By judging, the memory unit 17 stores data corresponding to six.

In the repetition of the above process, the second detector 7 outputs the enable signal to the third detector 8 so that the third detector 8 is ready to receive a specific frequency.

As a result, the number of detectors can know the password of the mobile card 3 by measuring the frequency scan of the microcomputer 13 and the received electric field strength received from the microcomputer 13, and the scan and the electric field strength measurement are performed in a very short time. will be.

Therefore, the microcomputer 13 digitizes and stores each tuning frequency included in the plurality of detectors, and the plurality of data to be stored is a unique number already stored in the memory unit 17, that is, a portable card. The password is compared with the password of the car audio 1 corresponding to the password in (3). If it is determined that the result of the comparison does not match, the low signal is applied to the Darlington circuit unit 20. The predetermined light emitting lamp is turned on from the incident operation of the microcomputer 13 so as to indicate that the passwords of the mobile card 3 and the car audio 1 do not coincide with each other. .

On the other hand, if a kind of data retrieved from the frequency scan of the mobile card 3 and the password stored in the memory unit 17 match, the output signal of the microcomputer 13 is inverted high, which drives the Darlington circuit unit 20. Therefore, the car audio driver 19 which performs the main function of the car audio 1 can receive the backup power source 18. As a result, if the user does not bring the portable card 3 close to the car audio 1, the car audio is never operated, and thus theft of the car audio can be prevented.

As described above, the present invention provides a coil having a predetermined turn and Henry inside a portable card and capacitors having different capacities inside a plurality of detectors, and a transmitter having a voltage controlled oscillator inside a car audio. By configuring the receiving side for measuring the electric field strength, by sequentially sending a plurality of tuning frequencies used in the portable card, the car audio can recognize the password of the portable card from the frequency scan so that the car can By operating the audio, the user's portable to prevent car audio theft is simplified, the small volume of the mobile card is less risk of loss, and the ease of use is not only easy to increase the convenience, but also inside the car audio As the system is operated from deformation of the circuit, deformation or design of the mold is necessary to prevent theft. There is no effect that can widen the range of use.

Claims (4)

In the car audio (1), A transmission / reception unit (2) mounted on one side of the front panel of the car audio (1) to transmit a plurality of microwave frequencies and measuring the received field strength of the transmission frequency, and an output signal of a specific frequency of the transmission / reception unit (2) Proximity switching card characterized in that consisting of a portable card (3) for judging whether or not according to the car anti-theft device using the same. 2. The portable card (3) according to claim 1, wherein the portable card (3) has a coil (5) having a predetermined turn and Henry provided inside the outer card of the portable card (3), and connected in parallel with the coil (5) to have a specific capacity. Characterized in that it comprises a plurality of capacitors (C1, C2, C3, C4) and each detector (6, 7, 8, 9) is provided with a capacitor for the impedance of a specific capacitance (C ') Close-up switching card. 2. The microcomputer 13 according to claim 1, wherein the transmission / reception unit 2 performs batch processing and comparison output of data to be used for transmission and reception, and a counting circuit is provided, and a counting signal of the microcomputer 13; A die conversion unit 12 for converting it into an analog signal at output, a voltage controlled oscillation unit (VCO) 11 for oscillating a frequency in accordance with an input voltage output from the die conversion unit 12, and the voltage controlled oscillation unit ( Transmitter 10 for transmitting the microwave output from the VCO: 11, A receiver 14 for receiving a frequency transmitted from the transmitter 10, an electric field strength measuring unit 15 for measuring an electric field of a signal received through the receiver 14, and the electric field strength measuring unit 15 When a predetermined electrical signal is output according to the electric field strength received from the AD conversion unit 16 for converting it into a digitized signal, the digital signal output from the AD conversion unit 16 to the microcomputer 13 described above. When applied, the anti-theft device of a car audio using a proximity switching card comprising a memory unit 17 for storing or reading data in accordance with the result determined from the numerical value of the digital signal. 2. The anti-theft device for car audio according to claim 1, wherein the anti-theft device of the car audio (1) receives power from a backup power source (18).