JPS6154484A - Doppler effect crime prevention device - Google Patents

Abstract

PURPOSE:To prevent malfunction due to the variance in a component characteristic and a temperature characteristics of the component by processing the direction of quadrant transistion and the number of times of inversion digitally. CONSTITUTION:A receive signal Ein received by a receiver 2 is frequency-converted through a converter circuit 20 and a quadrant signal generating circuit 27 sends out quadrant signals from output terminals I -V corresponding to the respective quadrants of the rotational vector of the receive signal Ein. A quadrant transition direction detecting circuit 31 sends out a digial signal having an H or L level according to the rotational vector of the receive signal Ein moves to another quadrant counterclockwide or clockwise. An integration circuit 37 integrates the output of the quadrant transition direction detecting circuit 31 and the quadrant transition is not outputted when the direction of the quadrant transition is the same. When the direction of the quadrant is inverted, a transition detection signal is generated and when the output of a threshold value circuit 32 goes down to the level L, a clock signal CK outputted from a clock generating circuit 33 is counted by a comparing circuit 34; when the counted value of the comparing circuit 34 attains to a set value, a decision circuit 35 sends out an alarm signal.

Description

[Detailed Description of the Invention] [Technical Field 1] The present invention relates to a Doppler effect type security device, more specifically,
The frequency of the reflected wave generated by the movement of the object to be detected after emitting a detection wave such as an ultrasonic wave or microwave of a predetermined frequency is the frequency l! This paper relates to a Doppler effect type security device that detects the movement of an object by detecting the L shift.

[Background technology 1] Generally, this type of Doppler effect type security device emits ultrasonic waves or microwaves of a predetermined frequency as a detection wave,
This device detects when an intruder moves within the detection area, and the reflected waves undergo a frequency shift called the Doppler effect. 5. Unlike distance-limited security devices that detect intruders based on fluctuations in the strength of reflected waves, it does not detect objects that do not move even within the detection area, so it has nothing to do with the shape of the detection device 17a. Well, even in a room with a complicated shape and a lot of equipment, like the inside of a car.

Although it has the advantage that almost the entire area can be used as a detection area, it has the disadvantage that it may malfunction as described below.

In the following description, the invention disclosed in Japanese Unexamined Patent Publication No. 55-63774 will be described as a conventional example. As shown in FIG. 8, the output of the oscillation circuit 10 is applied to the transmitter 1, and the transmitter 1 emits an ultrasonic wave into the air.The reflected wave is received by the receiver 2 and is an electrical signal. is converted to The received signal E111 converted into an electric signal is converted into monthly intermediate signals E and E having different phases by a converter circuit 20 consisting of a phase shift circuit 22, an elbow mixer circuit 21a, 21b, and a pair of amplifier circuits 23a, 231]. ', and both intermediate signals E
, the binary number conversion circuit 26 determines in which quadrant the received signal E111 exists in a vector plane whose unit axis is E'.
a, 26b, a quadrant signal generating circuit 27, etc., and the output of this quadrant detecting circuit 25 is applied to a quadrant transition direction detecting circuit 31. In the quadrant transition direction detection circuit 31, when the received signal Ein moves to another quadrant in the vector plane, the level is set to 1' level or L depending on whether the direction of movement is clockwise or counterclockwise around the origin. Outputs a level digital signal. Here, the direction in which the quadrant moves corresponds to the direction in which the intruder moves.
When moving away, it turns clockwise. The output of the quadrant transition direction detection circuit 31 is applied to an integration circuit 38 to integrate the number and direction of quadrant transition, and the output of this integration circuit 38 is applied to a threshold circuit 32. In the threshold circuit 32, a first set voltage smaller than half the voltage of the power supply voltage Vcc and a second set voltage larger than the voltage are set, and the input signal is set at the first set voltage. A notification signal is sent when the voltage is less than or equal to the second set voltage or more than the second set voltage. That is, when the quadrant transition occurs multiple times and the direction of the transition is the same for a predetermined number of times or more, the integration circuit 38
When the output becomes below the first set voltage or above the second set voltage, an alarm signal is sent from the threshold circuit 32. The alarm signal sent from the threshold circuit 32 is input to a display drive circuit 36 that drives a display that notifies an alarm. Therefore, if the intruder is moving in the same direction, an alarm signal is output from the threshold circuit 32, and the display drive circuit 36 is driven to notify the presence of the intruder.

By the way, in addition to the received signal E111 reflected by the moving object, the receiver 2 also receives noise such as a bell sound, so whether it is a reflection from the detected object or noise. Is it necessary to determine the In general, noise has a completely different phase from the reflected wave, and is caused by irregular transitions of quadrants in the vector plane.
), clockwise transitions and counterclockwise transitions occur with approximately the same probability, and it is considered that the desired reception signal Ein1) also has a large number of transitions occurring per unit time. However, in the conventional example, the time constant of the integrating circuit 38 and the threshold value circuit 3
By appropriately selecting the first and second set voltages of No. 2, the clockwise transition and the counterclockwise transition are canceled out and noise is removed.

However, even for reflected waves that are not noise, the number of quadrant transitions that occur within a unit time is constant due to differences in the direction of movement relative to the device, differences in movement speed, differences in the shape of the reflecting surface, etc. Therefore, it is necessary to separate reflected waves and noise by setting the time constant of the integrating circuit 38 and the first and second set voltages of the threshold circuit 32 to appropriate values.

Depending on this setting value, an alarm may not be output when an alarm signal is required, or an alarm may be output when it is unnecessary. For example, when a device is placed inside a car, the form of quadrant transition is different when the door is closed and when a hand enters the car, as shown in Figures 9 and 10, respectively. The rate of change of the output signal of the integrating circuit 38 is different. For this reason, it is necessary to set the time constant of the integrator circuit 38 and the set voltage of the threshold circuit 32 so that noise is canceled out and an alarm signal is reliably issued when there is an intruder. circuit (1νI
In the construction, as mentioned above, the number of transitions of the inlay in the vector plane of the received signal is determined at t11 by the combination of the integrating circuit 38 and the threshold circuit 32 and the analog processing. Even when the value was determined, there were times when the device did not operate as expected due to variations in component characteristics or temperature characteristics of the components.

[Objective of the Invention 1 The present invention has been made in view of the above points, and its main purpose is to prevent malfunctions caused by variations in component characteristics, temperature characteristics of components, etc. There is no Doppler effect in providing a security device.

[Disclosure 1 of the Invention The configuration of the present invention is explained based on FIG. 1. In the following description, an example will be shown in which ultrasonic waves are used as waves for detection of the object to be detected, but the waves for detection may be microwaves, for example, as long as the wavelength power is about 1 cm or smaller.

The transmitter 1 is driven by the output of an oscillation circuit 10 that oscillates at a constant frequency, and the transmitter 1 emits ultrasonic waves into the air. Ultrasonic waves emitted from the transmitter 1 are reflected by surrounding objects, and the reflected waves are received by the receiver 2, which converts them into electrical signals. Transmitter 1 and receiver 2
In addition, it is composed of piezo elements, etc., and the transmitter 1 emits ultrasonic waves that match the frequency of the applied electric vibrations, and the receiver 2 emits ultrasonic waves that match the frequency of the received ultrasonic waves. The electric vibration is output as a received signal E in. Receiver 2
The received signal Ein received by the converter circuit 20 undergoes frequency conversion. converter circuit 20
is a pair of mixer circuits 21a, 211+ and a phase shift circuit 22
and a pair of amplifier circuits 23a and 231J. The first mixer circuit 21a is supplied with a reference signal Et whose phase is advanced by 90 degrees from the output of the oscillation circuit 10 through the phase shift circuit 22.
and the reception signal Ein received by the wave receiver 2 are applied, and an intermediate signal E having a frequency difference therebetween is output, and the second mixer circuit 211) receives the reference signal which is the output of the oscillation circuit 1 (). When E and the received signal E111 from the receiver 2 are applied, an intermediate signal E with a frequency difference between them is output. Therefore, the January intermediate signals E and E', which have different phases from each other, are outputted from the converter circuit 20. Here, when an object that reflects ultrasonic waves approaches the receiver 2, the frequency of the reflected wave becomes higher than the oscillation frequency, so the phase of the intermediate signal E leads the phase of the intermediate signal E'1) ,)! ! When the object moves away from the receiver 2, the frequency of the reflected wave becomes lower than the oscillation frequency at b, so the phase of the intermediate signal E lags behind the intermediate signal E'. Therefore, in the vector plane with each intermediate signal E, E' as the basic axis, when the object approaches, the rotation vector represented by the received signal Ein rotates counterclockwise around the origin, and when the object moves away, it rotates clockwise. Rotate to.

Each intermediate signal E, E' is input to a quadrant detection circuit 25, respectively. The quadrant detection circuit 25 includes one elbow binary conversion circuit 26a, 261) to which each intermediate signal E, E'' is applied, a quadrant signal generation circuit 27, and a -month level detection circuit 23, .2.
81+ and an OR circuit 29. The binary number conversion circuits 26a, 261] output a dental signal of the l'' level or the L level depending on the sign of the intermediate signals E, E' (here, positive is assumed to be H level, and negative is assumed to be L level). Here, 1ilii binary number conversion circuits 26a, 26
1. The outputs correspond to the polarity X in the E-axis direction and the polarity Y in the E'-axis direction in a vector plane having the intermediate signals E and E' as basic axes, respectively. The quadrant signal generation circuit 27 determines in which quadrant the rotation vector of the received signal Eiu exists in a vector plane with both intermediate signals E and E' as the basic axes, and outputs the first to fourth outputs corresponding to each quadrant. Six level detection circuits 28a and 23b, from which quadrant signals are sent from terminals 1 to ■, receive intermediate signals E and E', respectively.
exists, that is, when the object reflecting the ultrasonic wave is moving, it is detected that the intermediate signals E and E' are above a predetermined level, and the off circuit 2
9 sends out an output if either intermediate signal E or E' exists. The output of this OR circuit 29 is sent to the next quadrant signal generating circuit 2'7 (intermediate signals E, E
The throat quadrant signal is sent out when a 'flash' is occurring.

The quadrant signal is applied to the l-transition detection circuit 30, and the received signal I
It is detected whether the rotation vector of Ein has moved from one of the quadrants to the quadrant of the dish. That is,
The transition detection circuit 30 includes a quadrant transition direction detection circuit 31, an integrating circuit 37, and a threshold circuit 32.
In the quadrant transition direction detection circuit 31, when the rotational vector of the received signal E1n moves to another quadrant in the vector plane, 14 levels or 14 levels are detected depending on whether the movement is counterclockwise or clockwise around the origin. Sends an L level dental signal. Here, the H level corresponds to the power supply voltage, and the L level corresponds to () ().The counterclockwise rotation is the H level, and the clockwise rotation is the L level.

The output of the quadrant transition direction detection circuit 31 is the above [4;
Keep the original value until it becomes a vector.

The integrating circuit 37 integrates the output of the quadrant transition direction detection circuit 31, and only when the output of the transition detection circuit 31 changes from the H level to the L level or from the L level to the H level, the integration circuit 37 integrates the output. The output is made to go from the I level to the L level, or from the L level to the H level.

That is, when the quadrant transitions are in the same direction, the quadrant transitions are prevented from appearing in the output.

In the threshold circuit 32, a voltage that is half of the power supply voltage \'cc is used as a reference voltage.1) A slightly smaller first set voltage■
1 and a second set voltage (2) that is slightly larger than that (1), the output of the quadrant transition direction detection circuit 31 is less than or equal to the first set voltage (2), or the set voltage of f52 is V.
If it is 2 or more, the output is set to L level, and otherwise, a transition detection signal is sent out which sets the output to H level.

Therefore, if the direction of the quadrant is reversed when a quadrant transition occurs, a short pulse-like transition detection signal is generated at that time, and it is detected that the direction of the quadrant transition has been reversed. The output of the threshold value circuit 32 is applied to the clock generation circuit 33, the comparison circuit 34, and the determination circuit 35. When the output of the threshold value circuit 32 becomes L level, the clock generation circuit 33 starts and the comparison circuit 34 is applied. and the judgment picture m35 are reset, and the clock signal CK output from the clock generation circuit (3) is counted by the comparator circuit 3.1.The clock signal C
When the quadrant shifts after starting counting K, the transition detection circuit 30 generates a shift signal of quadrant 1, so that the clock generation circuit 33 generates the clock signal CK from this point onwards.
At the same time, the comparator circuit 3.t also starts counting the clock signal CK from 1 anew. A predetermined value is set in the comparison circuit 34, and this set value is compared with the count value of the clock signal CK. Comparison circuit 3/1
When the count value reaches the set value, the judgment circuit 35 issues an alarm (
- A signal is sent, which causes the display drive circuit 3G to
is activated and no alarm is issued.

As described above, in the present invention, if the quadrant 11 is transferred and the direction of the transfer is reversed at that time, a transfer detection signal is sent out and digital processing is performed (1). Counts the number of reversals in the direction of the transition and reliably issues an alarm when the direction of the transition occurs a predetermined number of times within the vector plane of the received signal, regardless of variations in component characteristics or temperature characteristics of the component. For the sake of understanding, one circuit is shown in Fig. 2 and an example will be explained in detail below.
:lIl I will explain.

(Embodiment) The oscillation circuit 10 is a quartz crystal resonator 11, and outputs electrical vibration with a stable frequency.

The output of the oscillation circuit 10 is applied to a transmitter 1 composed of a piezo element or the like, and an ultrasonic wave having a frequency equal to the oscillation frequency of the oscillation circuit 1 () is emitted. The ultrasonic waves are reflected by surrounding objects and are received by the receiver 2. The reception signal Ein received by the wave receiver 2 is mixed with a reference signal Et, which is obtained by leading the output of the oscillation circuit IO by 90 degrees through the phase shift circuit 22, by the first mixer circuit 21a constituting the converter circuit 20. Further, the second mixer circuit 211) combines the reference signal EL' which is the output of the oscillation circuit, detects and amplifies the received signal Ein and the signal E1 (thread signal E1).
, l31'') are obtained. ' Here, we will further consider the intermediate signals C and E'. Let the base bar ← signals EL and EL' be the basic axis. When the received signal E111 is displayed on a vector plane, as shown in FIG. 3, the intermediate signals E and E'' are expressed as follows. However, for simplicity, the received signal Ein, the reference signal E, and E
l and ゛ are each sine waves.

E-IEin cosol:)'=iEin 3inθ
Here, θ is the phase angle between the received signal Ein and the base signal El. Regarding the phase relationship between the intermediate signals E and E', when an object that reflects ultrasonic waves approaches, the intermediate signal E It can be seen that the intermediate signal E' has a 90 degree advance (the dashed line in FIG. 3), and when the object moves away, it has a 90 degree delay (the 34th middle line). In addition,
This point is also explained in US Pat. No. 3,432,855 and the like. Objects that actually reflect ultrasonic waves do not have flat surfaces, and each part of a friend's body approaches or moves away at different speeds.
The received signal E111 is expressed as a composite vector of reflected waves, and except in special cases, the waveforms of the intermediate signals E and E' will not be sinusoidal waves, but will be distorted waveforms as shown in Figure 1. . However, no matter how distorted, the received signal Ein can be expressed as a point on the Cartesian coordinate plane with the origin at the tip of the vector representing the reference signal E L /;
), and in this vector plane the intermediate signals E, E'
are orthogonal to each other, so as shown in Figure 4, 1
The received signal E'11 can be expressed as a rotation vector on a vector plane with the intermediate signals E and E' as sample axes. When the rotational vector representing the received signal Ein rotates counterclockwise around the origin in a vector plane with intermediate signals E and E' as the basic axes, it means that the phase of the intermediate signal E advances with respect to the intermediate signal E'. , which means that when rotating clockwise, the phase of the intermediate signal E is delayed with respect to the intermediate signal E'. Furthermore, if the quadrant in which the rotation vector exists changes and the order in which the quadrant moves is detected, the direction of movement of the object can be detected.

Therefore, in order to find the quadrant in which the rotation vector is located, it is not necessary to increase the amplitude of the intermediate signals E and E' by 2vl, so we focus only on the polarity of the intermediate signals IE and IE', and ') Each intermediate signal E, E' is generated by the binary number conversion circuit 26a, 261+ created by J1'lj.
(If the destructiveness is positive, it becomes L level, and if it is negative, it becomes L level.) Signals By combining the sheets, it is possible to create a quadrant signal corresponding to the quadrant in which the rotation vector exists, as shown in Table 1.

The first table shows that the H level () is at the L level, and the wood shows that both the intermediate signals [, E' are below the predetermined level CJ, which means that the received signal E111 corresponds to a state in which the ultrasonic wave is below a predetermined level and the object that reflects the ultrasonic waves is located outside the detection area of the device. intermediate signal E
, E' are detected by level detection circuits 23a and 23b, which are comparator circuits. , Jt, so that if one of the intermediate signals E, E' is at a predetermined level or higher, the output of the OR circuit 29 becomes H level. The level of the received signal E111 is determined by the level detecting circuits 28a and 281) as described above, which set the output to H level if either of the intermediate signals E and E' are at a predetermined level V or above. The absolute value of the composite vector of the intermediate signals E and E' (that is, the absolute value of the received signal E111) may be detected, and if the absolute value is equal to or higher than a predetermined level, the output may be set to H level.

As described above, the binary number conversion circuits 26a, 261)
In the middle, the digital signals X and Y obtained by setting j and the output of the OR circuit 29 are inputted to the quadrant signal generating circuit 27. The quadrant signal generation circuit 27 is a defog circuit constructed of four three-man NAND circuits and two inverter circuits so as to combine the signals shown in Table 1 above. Each output terminal of the NAND circuit 1~■
Of these, a quadrant signal is output in which the terminal corresponding to each quadrant on the vector plane is at L level. Here, since the output of the OR circuit 20 is connected to one input terminal of all the NAND circuits, when the output of the OR circuit 29 becomes L level, the binary 41L conversion circuits 26a, 261]
Regardless of the output of
A specific quadrant is not designated when the reflective object is outside the detection area.

As described above, the quadrant signal generation circuit shifts to create a quadrant signal corresponding to the quadrant in which the rotation vector representing the received signal Ein exists in the vector plane with the intermediate signals E and E' as the basic axes. A quadrant signal is applied to a quadrant transition direction detection circuit 31 in order to detect movement of the quadrant in which the rotation vector exists. The quadrant transition direction detection circuit 31 consists of two R379777077 circuits.
k, r, memory circuit 40, and four AND circuits-14
It consists of 8 NAND circuits and a logic circuit equipped with 8 diodes. Each diode is connected to the output terminal of the AND circuit or NAND circuit in the direction 4 (jt,
He is preventing reverse 1A players. In the memory circuit 4(), the reset terminal and the send terminal of the first R37 lip 70 amplifier circuit are respectively connected to the output terminal 1 and (2) corresponding to the first quadrant and the third song quadrant of the quadrant signal generating circuit 27. Further, the reset terminal and set terminal of the second R379717071 circuit are connected to the output terminals (2) and (2) corresponding to the second quadrant and the fourth quadrant, respectively. Shut up, 2
The quadrant in which the digital signals X and Y, which are the outputs of the decimal conversion circuits 26a and 26b, and the received signal Ein exist, and the storage circuit 40
The relationship with the output of is shown in the fjS2 table below.

Table 2 Therefore, when transitioning from an odd-numbered quadrant to an even-numbered quadrant, the state of the output terminal 11, q of the first RS flip 70 knob circuit does not change regardless of whether the direction of transition is left or right. to maintain the previous state, and when transferring from the even quadrant to the odd quadrant, the second R379717071
The state of the output terminals r and s of the circuit or the state just before that state is maintained. Therefore, when the quadrant transfers, the memory circuit ↓()
Output terminal: Since the quadrant signal before the transition from N to S is output, by combining this with the quadrant signal that is the output of the quadrant signal generation circuit 27, the received signal Ei
It is possible to detect whether the corresponding rotation vector has shifted to the left or right. The AND circuit and the NAND circuit of the direction detection circuit 31 for moving the quadrant 11 are applied with each quadrant signal and the output of the R S 717 knob 70 knob circuit to which the quadrant signal adjacent to the quadrant is applied 1). It is connected to a NAND circuit when the quadrant signal stored in the storage circuit 40 is used to represent the quadrant on the left after one transition, and to an AND circuit when the quadrant on the right is to be represented. . Therefore, the signals output to the output terminals a to 11 of the AND circuit and the NAND circuit and the signals output through the diodes
'rii Finally, the relationship between the signal that sends quadrant 1 to the output terminal Z of the movement direction detection circuit 31 and the quadrant signal that is the output of the quadrant signal generation circuit 27 is as shown in Table 3. Become.

The underlined portion in Table 3 shows the signal actually output as the output of the quadrant transition direction detection circuit 31 due to the connection relationship between the AND circuit or the NAND circuit and the diode. As described above, in the vector plane with the intermediate signals E and E' as the basic axes, if the quadrant in which the times 1ij vector representing the received signals 'I' and E111 exists changes °r, then (IH limit・1 is shifted) Depending on the direction of change in the quadrant, the output of the direction detection circuit 31 becomes H level when moving to the right FJ4, and becomes L level when moving to the left side.

Incidentally, although the quadrant transition direction detection circuit 31 is provided with a logic circuit including a NAND circuit, an AND circuit, and a diode as described above, this logic circuit can be replaced by a switch circuit 371 to be described next. That is, if we look at the operation of the second memory memory circuit 40 from a different perspective, the first memory circuit 4() operates as shown in the table below. Here, 1 to ■ are the received signals E11 in each quadrant.
Indicates that a rotation vector corresponding to 1 exists. Further, the → symbol indicates the direction and section of the quadrant l transition.

Table 4 Therefore, as shown in FIG. 5, the input terminal of the switch circuit 37 is
is connected to the control terminal Co of the switch circuit 37.
I: If the switch circuit 37 that operates as shown in Table 5 is used to apply the & limit signal, then
At the output terminal Z of the switch circuit 37, an output similar to that of the logic circuit described above is obtained.

Table 5 Therefore, for example, when the rotation vector exists in the tS1 quadrant, the signal from the output terminal S of the storage circuit 40 is output to the output terminal Z of the switch circuit 37, and as is clear from Table 4, When the rotation vector moves from the 71st Song limit, an H level signal is output to the output terminal Z, and when it moves from the second quadrant, an L level signal is output to the output terminal Z. Similarly, when there is a rotational vector in the second quadrant, the signal at the output end 1 of the memory circuit 40 is output from the switch circuit 37, and in the third quadrant, the signal at the output end 1 is output, and in the fourth east limit, the signal at the output end 1 is output. A signal is output.In this way,
When the transition is clockwise 1), an output signal of level 14 is obtained, and when the transition is counterclockwise, the output signal is L level. Therefore, this switch circuit 7 can be replaced with two logic circuits.

It should be noted that without the quadrant signal, it is impossible to define the direction of movement, so the switch circuit 37 is configured not to select any of the input signals.

The output of the quadrant transition direction detection circuit 31 is applied to an integration circuit 37. In the integrating circuit 37, the quadrant transition direction detection circuit 31
At the output of ``Simple'', when this quadrant transitions, it maintains approximately the original output level, and only when the direction of quadrant transition is reversed, it sends out an output j that adjusts the output level to the direction of the transition.For example, The transition to the left is 1),
When the next quadrant transition occurs, the output 1 of the integrator circuit 37 is kept at the I level, and when the next quadrant transition occurs or the clockwise rotation occurs, it changes to the L level. .

The output of the integrator circuit 37 is applied to the threshold circuit 32. The threshold value circuit 32 is a window comparator circuit and has a first voltage centered around one-half voltage of the power supply type riVcc and slightly higher than that. The second set voltage V: is set to be slightly lower than the set voltage ＼゛1, and if the voltage is higher than the first set voltage ＼；1 or lower than the second set voltage V2, the output will be output. Therefore, when the output of the integrating circuit 37 is equal to or higher than the first set voltage V3, that is, when the quadrant transition is continuously counterclockwise, and when the output of the integrating circuit 37 is When the output is lower than the second set voltage V2, that is, when the quadrant transition is continuously clockwise, the output of the threshold circuit 32 becomes L level. A voltage dividing circuit 41 is provided at the end to take out a voltage of 1/2 of the power supply voltage Vcc, and the output of the integrating circuit 37 is set to the first set voltage %.
The input voltage is set to H level when it is between 'l and the second set voltage\pa. Therefore, when the direction of the quadrant transition is reversed, the output of the integrating circuit 37 changes from the H level to the L level, or from the L level to the H level, so as shown in FIGS. 6 and 7, A medium narrow pulse is output to the output terminal (j) of the threshold (direct circuit 32), and is kept at the I-level when the direction of the quadrant (1g shift) is not reversed.Here, II of the integrating circuit 37;
7 constants, resistors R1 to R3 that set the first set voltage \°1 and the second set voltage ~'2 of the threshold circuit 32, and resistors R4 and R3 that constitute the voltage divider circuit 11. It is not necessary to set the resistance value very strictly; it is sufficient to set it to a value that allows the above-mentioned operation. The output of the threshold circuit 32 sends out an intermediate pulse as a transition detection signal only when the direction of quadrant transition is reversed, regardless of the number of quadrant transitions.

The output of the threshold circuit 32 is applied to a black/cross generating circuit 33 and a counter circuit 42. The counter circuit 42 has both the functions of the comparison circuit 34 and the 1-11 constant circuit 35.
The number of clock signals CK output from the clock generation circuit 33 is counted when the output from the lower value circuit 32 is at L level. And clock signal C
When the number of K reaches a predetermined number, an alarm signal is sent to the output terminal Q of the counter circuit 42, and this alarm signal drives the relay Ry provided in the display drive circuit 3G. The appropriate alarm means connected to the contact point is activated to issue an alarm.

By the way, both the clock generation circuit 33 and the counter circuit 42 are reset when the output of the threshold circuit 32 reaches the I level.
It is possible to operate only while the output is at L level. Here, if we compare the received signal Ein, which is an ultrasonic wave reflected by a moving object, with a noise such as a bell sound, the latter has more transition reversals per unit time, so the clock The number of times that the generation circuit 33 and the counter circuit 42 are reset is much smaller when the alarm output error reception signal Ein is received than when noise is received. Therefore, for example, in the counter circuit 12, the clock signal C
If we set it so that an alarm signal is output when 8 K is counted, then when an ultrasonic wave reflected by an object moving in a certain direction is received, the alarm signal will be output as shown in Figure 6. From the time a quadrant transitions until the next transition occurs (this clock signal CK can be counted 8 times and an alarm signal is sent out. If it changes irregularly in a short period of time, as shown in FIG. 7, the clock generation circuit 33 and the counter circuit 12 are reset before eight clock signals CK are counted. This is because no alarm signal is output from the output terminal Q.

Here, it is determined whether the 'ζ alarm signal should be sent out based on the period of the clock signal CK, so it is desirable that the clock generation circuit 33 has as little period variation as possible. Oscillation circuit 10 for applying
Clock signal
This is a good thing for K.

As described above, irregularly occurring noise, the object reflected by a moving object, and the -[received signal IEin] are discriminated based on the difference in the number of times the direction of movement in quadrant 11 is reversed per unit time. In addition to conventional analog processing in which irregular 3 and limit transitions are canceled out by an integrating circuit, the signal is processed digitally, so the values set in the circuit are accurate. It is reflected in J et al.

[Effects of the Invention 1] The present invention has the following advantages: 1. In a vector plane whose basic axis is the intermediate signal of one signal having a different phase, a quadrant signal corresponding to the quadrant in which the rotation vector representing the −ζ received signal exists,
a quadrant detection circuit that sends out a transition detection signal, a transition detection circuit that sends out a transition detection signal every time the direction of the quadrant transition is reversed when the terminal signal moves to a quadrant of the plate of the vector plane, and a clock that is started by the transition detection signal. A generation circuit, a comparator circuit that counts the clock signal sent from the clock generation circuit that is reset by the transition detection signal from the time of reset, and compares the counted value with the set value, and sends out an alarm signal when the set value and the counted value match. tlIl rotation, and the display unit +I+ circuit that drives the display device to notify the alarm in response to the alarm signal. 1 is shifted in the opposite direction by 111 times, the information is sent to the broadcaster and the received signal is separated from the noise, so this can be done by counting the number of times of reversal or by performing differential processing. This is because the set value does not change due to variations in component 1 and y properties and the temperature of the im product. As a result, the desired received signal and noise can be discriminated according to the settings, and there is an advantage that malfunction does not occur.

In addition, in order to accurately count the number of shifts in the 11 quadrants per unit time, it is only necessary to manage the accuracy of the clock signal, and if a crystal oscillator is used, it is possible to create a device that does not malfunction. This structure has the advantage of being simple and inexpensive.

[Brief explanation of the drawing]

10 is a block diagram showing a door puller effect type security device according to the present invention; FIG. 2 is a circuit diagram showing an embodiment of the present invention;
Figures 3 and 1 are operation explanatory diagrams showing the principle of operation of the same as above, and Figure 5 shows an inch circuit used in the same. An operation explanatory diagram showing the signals of each part of the device when a signal to be notified is received and when noise is received, FIG. 8 is a block diagram showing a conventional example, and FIGS. 9 and 10 are problems with the conventional example. It is an operation explanatory diagram showing the operation. 1 is a transmitter, 2 is a receiver: (:1.10 is an oscillation circuit, 20
is a converter circuit, 25 is a quadrant signal detection circuit, 30 is 1
7 a shift detection circuit, 33 a clock generation circuit, 34 a comparison circuit, 35 a 1-11 constant circuit, 36 a display drive circuit, =
>1:+ is a memory circuit. Agent Patent Attorney Ishi 1) Chief Shichikei 1'. @3 Figure 4th cause! With low QO (L)-woke N-fu Q
. −−× Σ −EF! ≧!

Claims (5)

[Claims] (1) An oscillation circuit that outputs electrical vibrations at a constant frequency, a transmitter that emits detection waves into the air to which the output of the oscillation circuit is applied, and a receiver that receives reflected waves from objects and converts them into electrical signals. a converter circuit that converts the received signal output from the wave receiver into a pair of intermediate signals having mutually different phases;
A quadrant detection circuit that sends out a quadrant signal corresponding to the quadrant in which the received signal exists in a vector plane with both intermediate signals as the basic axes, and a quadrant signal that moves to another quadrant of the vector plane and the direction of the quadrant transition is reversed. A transition detection circuit that sends out a transition detection signal every time the transition occurs, a clock generation circuit that is started by the transition detection signal, and a clock signal that is reset by the transition detection signal sent from the transition detection circuit and sent out from the clock generation circuit. A comparison circuit that counts from and compares the counted value with the set value, a judgment circuit that sends out an alarm signal when the set value and the counted value match, and a display that drives the display that notifies the alarm in response to the alarm signal. 1. A Doppler effect type security device comprising a device drive circuit. (2) A level detection circuit is provided for detecting that the intermediate signal is above a predetermined level, and when the intermediate signal is below the predetermined level, at least one of the quadrant signal and the output signal of the transition detection circuit is prohibited. A Doppler effect type security device according to claim 1. (3) The Doppler effect type crime prevention system according to claim 1, wherein the transition detection circuit comprises a memory circuit constituted by a pair of flip-flop circuits that stores the quadrant before quadrant transition. Device. (4) The Doppler effect type security device according to claim 3, wherein the transition detection circuit comprises a logic circuit that combines the quadrant signal and the output signal of the storage circuit. (5) The transition detection circuit includes a switch circuit with other inputs and one output, and the output signal of the memory circuit is applied to the input of the switch circuit, and one signal is specified by the quadrant signal or a plurality of signals including quadrant signal information. 4. The Doppler effect type security device according to claim 3, wherein the input signals are transmitted as output.