JPS598095A - Burglar preventor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] This relates to an anti-theft device that emits an alarm.

It is well known that this god's anti-theft device was designed to cut off the beam of light to the object to be monitored, and then issue an alarm when the interruption was released. It cannot be seen by the eye, which limits its use.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an anti-theft device that can be attached to an object to be monitored and detect movement of the object with high sensitivity. A method for this purpose is to use a magnet as a spring to attach the lid L.
The first idea is to use a Hall element or the like to sense the vibrations of the magnet that occur when the object to be monitored is moved, but this becomes impossible to sense if the object to be monitored is moved quietly. Therefore, in the present invention, changes in magnetic flux density due to movement of a magnet that can respond to earth's magnetism are sensed by a magnetic sensing element for position identification of the magnet.

Next, the present invention will be explained based on the illustrated embodiments. .

In FIG. 1, reference numeral 1 is a spherical magnet supported by a liquid in a transparent container 2 so as to not only respond to the earth's magnetic field but also function as a magnetic compass at any inclination according to the present invention.

Part 1: The lever magnet 1 has a fish-centered force so that the magnetic pole facing horizontally on the central Ill wall is always stable on the horizontal plane, and the central circumferential wall has an azimuth scale 3.

As such a magnet 1, a commercially available car compass may also be used. .

5 is oriented toward the base 3 or the water sV plane. Erosion stone 1 in the state
A magnetic sensing element, such as a Hall element, is attached to the surface of the transparent container 2 so as to face the response path of the magnetic pole of the magnet 1, and senses the strength of the magnetic field as an electric signal depending on the relative position with respect to the magnet 1. Therefore, as for the detection signal, for example, in the case of a Hall element, an output signal with the maximum amplitude is generated when the position is in the north direction, zero in the east direction, maximum amplitude with opposite polarity in the south direction, zero in the west direction, and so on. Further north, the amplitude changes sinusoidally, returning to its original maximum amplitude. When the base 3 is tilted in the same direction, the output at the horizontal position of the base 3 becomes maximum and changes in a decreasing direction.

Reference numeral 10 denotes a fluctuation detection circuit for detecting fluctuations in the detection signal of the magnetic sensing element 2, and a DC amplification circuit 1 for the detection signal of the magnetic sensing element 5.
1, a switch circuit 12 whose amplified output is input,
A power supply detection circuit 13 detects when the power supply 18 is turned on by the switch 19 and turns on the switch 12 for a predetermined period of time, and the amplified output supplied via the switch circuit 12 is maintained for a long time. High School Cain Bee Dance FET
Compare the memory circuit 14 using a subsequent capacitor, its memory signal, and amplified output 1. , and a comparator circuit 15 which generates a fluctuation detection signal as a theft alarm signal when a difference of more than a predetermined level takes into account circuit drift, etc. between the two levels.

Reference numeral 17 is an alarm device that emits a sound from a ceramic buzzer, a light from an LED, etc. in order to warn of theft in response to the theft alarm signal 3. These alarms are performed not at one location but at multiple locations. It is also possible to issue a warning after transmitting the fluctuation detection signal, which is theft information, to a long distance using radio waves, ultrasonic waves, etc.

When using the
Place the anti-theft device on the base 3 in the direction of the wind,
Turn on switch 1 after seeing that the magnet l has stabilized in the north direction.
Insert into 9'. As a result of this, the turtle W input/recovery circuit 13 turns on the switch circuit 12 for a predetermined period of time, and the circuit 14 has the magnetic pole of the magnet 1 and the magnetic sensing element 5. ! A detection signal of /ζ level corresponding to the 1-point relationship is amplified by the amplifier circuit 11 and held. When the attaché case is moved in this state, the magnetic sensing element 5 is
The level of the detection signal fluctuates, and when the comparison circuit 15 senses the fluctuation, the alarm 17 is activated. Even if the vibration stops, the alarm 17 continues to operate as long as the direction is different from the memorized direction. For example, even if a folded attache case is moved quietly along the floor, the alarm 17 will be activated as soon as its orientation deviates from its resting state. Further, even if the attache case, that is, the magnet 1 is tilted in the same direction, the level of the detection signal of the magnetic sensing element 5 changes, so that an alarm is emitted.

FIG. 2 shows a variation detection circuit 20 according to a second method, which is different from the variation detection circuit shown in FIG. From the comparison circuit 23, m= is established. , when the level of the detection signal of the magneto-sensitive element 5 fluctuates, the output signal of the delay circuit 22 is delayed according to its time constant, and in order to follow the fluctuation, the comparator circuit 23 detects the fluctuation detection signal for a period corresponding to the delay time. Supplied to alarm device 17. In this method, since there is no need to memorize the orientation, it is not affected by the temperature characteristics of the magnetic sensing element 5, the DC amplifier 21, etc.

Note that the alarm 17 may be configured to operate for a certain period of time or until reset even after the fluctuation detection signal disappears.

FIG. 3 shows a variation detection circuit 3° according to the third method, which includes an AC amplification circuit 31 that amplifies the variation in the detection signal of the magneto-sensitive element 5, and a DC amplification circuit 31 that converts the AC output signal into a DC signal. The conversion circuit 32 and its DC level are monitored, and 9r
For example, when the magnet 1 changes direction or the magnet 1 vibrates, the alternating current amplifier 3 amplifies the fluctuation component. The amplified output is converted into a DC signal by the DC conversion circuit 32, and when the DC level exceeds the discrimination level of the UNUMMIT circuit 33, a fluctuation detection signal is generated. In addition, it is conceivable that the alarm 17 should be operated for at least a certain period of time even after the fluctuation detection signal disappears.

FIG. 4 shows a variation detection circuit 40 according to the fourth method, which includes a DC amplification circuit 41 for the detection signal of the magneto-sensitive element 5 and a variable resistor etc., which can generate a signal at a level corresponding to the direction. When using the circuit composed of the voltage generation circuit 42 and the comparison circuit 43, when the magnet 1 is in a stable state, the two human power signals of the comparison circuit 43 are matched in advance by adjusting the resistor (h) above, and the alarm is activated. ] Stop the operation of 7. If the orientation of the magnet 1 changes or vibrates from this state,
Since the output signal level of the DC amplifier circuit 41 is different from that of the azimuth voltage generation circuit 42, a fluctuation detection signal is generated from the comparison circuit 43.

No. 5 (8) shows a fluctuation detection circuit 50 according to the fifth method, which includes a DC amplification circuit 51 for the detection signal of the magnetic sensing element 5, and an A, D conversion circuit 52 for digitizing the amplified output.
, a digital memory circuit 53 that stores the digital output information, a timing generation circuit 54 that causes the memory circuit 53 to take in data at divine timing when the power is turned on or by an external switch, etc., and a digital memory circuit 53 that stores the digital output information. A digital comparator circuit 55 generates a fluctuation detection signal when a difference of more than a predetermined level occurs between the memory outputs.14 In this case, the bearing at rest can be stored as a digital value in the memory circuit 53 without fluctuation. I can,
This is particularly convenient for long-term monitoring of fixed objects such as safes.

FIG. 6 shows an embodiment with a count circuit for counting the number of azimuth fluctuations, including a timer circuit 61 that generates a predetermined pulse signal in response to a fluctuation detection signal, and a timer circuit 61 that generates a predetermined pulse signal in response to a fluctuation detection signal, and an n1 constant circuit in response to a fluctuation detection signal. A timer circuit 62 generates a timer signal at the timer circuit 62, and a pulse count circuit 6;3 performs a non-counting of the pulse signal of the timer circuit 61 until it is reset by the timer signal from the timer circuit 62. , the number of times is 111
A decoder circuit 64 capable of level discrimination that generates a signal sound when decoding 1 and reaching a set value, a holding circuit 65 that holds the decoder signal, and a pulse signal from the timer circuit 61 and holding from the holding circuit 65. An adder circuit 66 is added which functions as an OR circuit with the signal. When the direction changes, a pulse signal of a predetermined width is supplied from the timer circuit 61 to the alarm device 17 via the addition circuit 66 each time, and an alarm is instantaneously issued. When a predetermined number of pulse signals due to azimuth fluctuations are counted within the time set by the timer circuit 62, a decoder signal is supplied from the tecoder circuit 64 to the holding circuit 65, so that instantaneous azimuth fluctuations are eliminated. The hold signal continues to operate the alarm 17 via the adder circuit 66 even after the alarm 17 has passed. As a result, if the monitored object moves slightly, an alarm will be issued instantaneously, but if the direction changes more than a set number within a set time than the actual theft, the alarm will be issued continuously. An alarm will be illuminated.

Unfortunately, in Fig. 6, it is not possible to simultaneously supply the count signal of pulse count = tit to the alarm 17 and make the alarm sound louder according to the count value.6゜In Fig. 7, it is not possible to supply the count signal of pulse count = tit to the alarm 17 at the same time, and to make the alarm sound louder according to the count value. This shows an embodiment, and includes a timer 73 for, for example, 10 minutes, and a switch circuit 74 controlled by the timer signal. When the power supply 71 is supplied to the timer 73 by the switch 72, the switch circuit 74 is turned on by the control signal, and power is thereby supplied to the main body circuits such as the magnetic sensing element, the fluctuation detection circuit, and the alarm. Even if the switch 72 is turned off for the purpose of theft, the timer circuit 73 continues to generate a control signal for 10 minutes and keeps the switch circuit 74 in the on state. Incapacitation is prevented.

As another embodiment of the power supply circuit, it is also possible to detect a transient voltage when the power is turned on or off, or to generate a pseudo fluctuation detection signal to generate an alarm in a similar manner. When the alarm is on, it is possible to check the power supply and circuit, and when the alarm is off, it is also useful for theft prevention. Furthermore, by setting the power supply circuit to self-hold when the alarm is activated, it is possible to make it impossible to turn off the power in the event of an alarm. FIG. 8 shows an embodiment of an intermittent operation type to save power consumption especially when a battery is used as a power source, and includes a timer circuit 81 that generates a pulse signal of a predetermined time width when a fluctuation detection signal is generated; A preset counter 82 generates a count output signal when the pulse signal reaches a predetermined count value, a circuit 83 generates a timing pulse at a rate of 1 second every 15 seconds, and each part is controlled by the timing pulse. A switch circuit 84 supplies the power supply voltage, a reset circuit 85 responds to the pulse signal and resets the reset counter 82 if the timer circuit 81 does not generate a pulse signal when the evening/l timing pulse is generated. Further, once a count output signal is generated, an alarm device 86 is added which holds it by a holding circuit 86 and self-holds the voltage of the cage 4jA to issue an alarm continuously.

In operation, as shown in FIG. 9, when a direction change occurs during Sunflink, an alarm signal is generated and the preset counter 82 is made to count for a time period of one second, for example, according to the pulse signal from the timer circuit 81. . If a pulse signal is not generated during sampling after the next 15 seconds, the preset counter 82 is reset, but if a predetermined number of pulse signals are continuously generated, the reset circuit 82 is reset.
5, in order to prevent the reset timing pulse from passing through, the preset value is reached and the alarm device 86 is operated in a self-holding manner to issue a continuous alarm. As a result, power is intermittently supplied to the Hall element or the subsequent circuit, and battery consumption can be greatly reduced.

In the case of the magnet shown in Fig. 1, if a compass index scale is not attached, it will not work even if the magnet has a structure with two female fixed points, which is stable even when the magnet is turned upside down. In addition, magnets that are pivoted so that they can only rotate in one plane, such as magnetic hooks and tooth-shaped magnets, can also be used, but in this case, when the magnet is tilted in the same direction, the magnetic sensing element is also interlocked. Therefore, the movement cannot be detected. In addition, in order to increase the sensitivity, a plurality of pairs of S and N poles may be arranged at predetermined angular intervals on the same rotational plane, instead of facing each other as in a compass. In the case of an attaché case or the like equipped with an electronic lock, the microcomputer may be used to turn on and off the power to the alarm device using a predetermined number. The sensor 1 of the present invention is installed at multiple locations using the alarm as a central monitoring device.
, 5 and a fluctuation detection circuit may be provided, and the respective fluctuation detection signals may be supplied to the central monitoring device as a theft alarm signal. In addition, this Shinzuki is used as a locking device to issue an alarm based on the theft alarm signal.
It can also be used as a 1-hour operation such as starting a monitor camera.

As described above, according to the present invention, by detecting changes in the magnetic field or magnetic flux of a moving magnet following weak earth's magnetism, the movement of the object to be monitored is magnetically amplified and sensed with high sensitivity. By the way, when the geomagnetic field is directly detected, the weak
Although only an electrical signal can be obtained and requires an expensive amplifier with low drift and high signal-to-noise ratio, the present invention allows use of an inexpensive amplifier to convert the magnetic signal into an electrical signal after magnetically amplifying it. In addition, it is possible to detect not only simple vibrations but also quiet movement, making it possible to reliably prevent theft. Furthermore, since it can be put into practical use as a battery-powered circuit device,
It can be used not only for monitoring fixed objects but also for portable use.

[Brief explanation of the drawing]

FIG. 1 shows the circuit configuration of the anti-theft device according to the present invention, and FIG.
Figure 5 shows a modification of the fluctuation detection circuit, No. 61'/,
1 shows an embodiment with a power cutoff function, FIG. 7 shows an embodiment with a power cutoff prevention function, and FIGS. 8 and 9 show an intermittent operation type embodiment. 1... Magnet 5... Magnetic sensing element 10, 20
．． 30.40.5u... Fluctuation detection circuit 17.86...
・Alarm agent Masaharu Fukutome Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 7 4 Figure 8 6 Figure 9

Claims (1)

[Claims] A magnet supported within a container so as to respond to earth's magnetism, a magnetic sensing element attached to the container and detecting the magnetic field produced by the magnet as an electrical signal, and a fluctuation detection circuit detecting fluctuations in the detection signal of this element. What is claimed is: 1. An anti-theft device comprising: a theft-preventing device which uses a fluctuation detection signal from the circuit as a theft-alarm signal.