JPS61234694A - Ultrasonic detector - Google Patents

Abstract

PURPOSE:To prevent a detecting means from being operated at the abnormality time by recognizing the operation of the detecting means consisting of transmitting and receiving oscillators automatically when an operation switch is closed and operating the detecting means after a prescribed time if the operation of the detecting means is normal and reporting abnormality if it is abnormal. CONSTITUTION:A detecting circuit part 1 is provided with a transmitting oscillator 2a which transmits an ultrasonic wave and a receiving oscillator 2b which receives the reflected wave of the ultrasonic. An operation confirming circuit 3 is operated for a prescribed time T set by a monostable multivibrator 24 after an operation switch SW is closed, and the operation of the detecting circuit part 1 is inhibited during this time, and abnormality is detected by the operation confirming circuit 3 while inhibiting the operation of the detecting circuit part 1 as it is; and if normality is confirmed by the operation confirming circuit 3, the operation confirming circuit 2 is stopped automatically, and the detecting circuit part 1 is operated. Thus, the operation is confirmed automatically when the operation switch SW is closed.

Description

Detailed Description of the Invention [Technical Field] The present invention relates to an ultrasonic detection device, particularly an ultrasonic detection device that detects an object by transmitting ultrasonic waves and receiving reflected waves thereof. It relates to a device that detects abnormalities such as failures and disconnections.

[Background Art 1] Conventionally, ultrasonic detection devices have been provided with an operation check circuit section that detects abnormalities such as failures or disconnections in the ultrasonic transducer provided in the detection circuit section, separately from the detection circuit section. However, when the detection circuit section is activated, separate activation switches are operated for the outside and operation confirmation circuit sections. Therefore Te1. In order to check the operation, it is necessary to operate a switch other than the activation switch of the detection circuit section, and it is troublesome to check the operation. If you neglect to activate the operation check circuit before activating the detection circuit, it is possible to turn on the activation switch of the detection circuit without actually noticing that a malfunction or disconnection may occur. However, because the operation has not been checked, abnormalities in the detection circuit may not be noticed.

In particular, when an ultrasonic detection device is used as an anti-theft device or an anti-intrusion device, a serious problem may occur if the ultrasonic detection device is intended to be operating but is not actually operating. Further, since two switches are installed, the installation space for the switches becomes large, and there is a problem that the device tends to become larger.

[Objective of the Invention 1 The present invention has been made in view of the points mentioned in -, and its main purpose is to detect abnormalities such as failures and wire breaks in the ultrasonic transducer using an ultrasonic detection device. The purpose is to provide an ultrasonic detection device that can automatically detect before operation.Other purposes are to simplify operation by using a single activation switch and to reduce the installation space for the switch. An object of the present invention is to provide an ultrasonic detection device.

[Disclosure of the Invention 1 (Examples) Examples of the present invention will be described below based on the drawings. 1st
The figure is a circuit diagram showing a schematic configuration, and the detection circuit section 1 as a detection means has a conventionally well-known configuration. That is, the detection circuit section 1 is an oscillation circuit 1 that oscillates at a constant frequency.
1, and a transmitting vibrator 2a driven by the output of the oscillation circuit 11.
, a reception transducer 2b that receives the reflected waves of the ultrasound transmitted from the transmission transducer 2a by an object, an amplifier 111 circuit 12 that amplifies the output signal of the reception transducer 2b, and an amplifier 111 circuit 12 that amplifies the output signal of the reception transducer 2b; a signal processing circuit 13 that outputs a detection signal when the sound wave is reflected by an object existing in the detection area and includes a reflected wave that satisfies a predetermined condition;
Notification circuit 1 that notifies an alarm when a detection signal is output from
It consists of 4. Piezo elements such as crystal or ceramics are used as the vibrators 2a and 2b. Here, depending on the type of signal processing circuit 13, for example, it may be a distance measuring type that detects the time from transmission to reception of ultrasonic waves, or it may be a distance measuring type that detects the time from transmission to reception of ultrasonic waves, or it may detect a frequency shift that occurs due to the movement of a reflecting object within the detection area. Although there are Doppler effect type ones, their configurations are conventionally known and will therefore be omitted. In any case, the ultrasonic wave sent out from the transmitting transducer 2a is reflected by an object existing in the detection area, and the reflected wave is received by the receiving transducer 2 + 3, and the received reflected wave is If the condition is met, the notification circuit □ will be activated and the presence of an object within the detection area will be notified.

Between the signal processing circuit 13 and the notification circuit 14 is another AND circuit 231, which will be described later, which together constitutes a switching means.
A human-powered AND circuit 15 is inserted, and the AND circuit 15
The output of the signal processing surface path 13 is inputted to one input terminal of the circuit, and a signal that becomes H level when an operation confirmation circuit 3, which will be described later, is not operating is inputted to the other input terminal. The notification circuit 14 is configured to be driven when both the sub-inputs of the AND circuit 15 are at a low level. Therefore, it is determined that the operation confirmation circuit 3 is not activated and that a reflected wave that satisfies the predetermined conditions has been received. The notification circuit 14 is driven.

The operation confirmation circuit 3 as an operation confirmation means is the wave receiving oscillator 2b.
A peak value detection circuit 31 holds the peak value of the signal received at a time for a period of about one cycle of ultrasonic vibration, and compares the output value of the peak value detection circuit 31 with a preset reference voltage Vref. It is comprised of a comparator circuit 32 that outputs an L level when the output value of the peak value detection circuit 31 is larger than the reference voltage Vref, and a delay circuit 33 that delays the change in the output of the comparator circuit 32. As will be described later, the delay circuit 33 has a time constant that is large enough to prevent a narrow pulse generated from the output of the comparator circuit 32 from passing through the operating switch S field input gutter. ' The output of the operation check circuit 3, which is the output of the delay circuit 33, is stored in a D flip-flop circuit (hereinafter referred to as 7-lip 7), which is a storage means.
It is input to the clock input terminal CK of 21 (abbreviated as 0tsubu). 7 The data input ID of the lip prop 21 is connected to the power supply Vcc, and the operation confirmation circuit 3
As a result, the positive logic output terminal Q of the buffer 21 becomes H level. The positive logic output terminal Q of the 7-lip 70 tube 21 is connected to the alarm 22 via a switching transistor Q, and when the positive logic output terminal Q of the 7-lip 70 tube 21 becomes H level, a buzzer or the like is activated. The alarm 22 is activated. The negative logic output terminal Q of the 7-lip 70-tube 21 is connected to the input terminal of one node J of the two-person AND circuit 23, and the other input terminal of the AND circuit 23 is connected to a monostable multi-bi break circuit (hereinafter referred to as a time-limiting means). 24 negative logic output terminals Q (abbreviated as monostable multi) are connected. Further, the output terminal of this AND circuit 23 is connected to one input terminal of the AND circuit 15 described above. The power supply Vcc is connected to the clock input terminal CK of the monostable multi 24 via the operating switch SW, and when the operating switch SW is turned on, a trigger is input to the clock input terminal CK of the monostable multi 24, and the negative Logic output IQ is maintained for a predetermined time T, I
− level. The negative logic output terminal d of the monostable multiplier 24 is also connected to the base 1 of the switching transistor Q2. Switching transistor Q2
is connected to the power supply part of the operation check circuit 3, and the input to the base is 1. When it reaches the level, it becomes conductive and supplies power to the operation check circuit 3).

The operation of the operation confirmation circuit 3 is shown in Fig. 2, which shows the signals of each part in Fig. 1.
This will be explained based on the diagram. Note that S and -S7 in FIG. 2 indicate signals of corresponding parts in FIG. First, when the operation switch SW is turned on, a signal is input to the clock input terminal CK of the monostable multi 24, and the negative logic output terminal Q of the monostable multi 24 is output for a predetermined period of time as shown in FIG. 2(b). T,
It becomes I-level. Also, this output allows AND circuit 2
Since one input terminal of 3 becomes L level, AND circuit 2
3 becomes L level, and the output of AND circuit 15 also becomes L level.
level. That is, in the detection circuit section 1, the input signal to the notification circuit 14 becomes L level, and the operation of the notification circuit 14 is prohibited, regardless of the presence or absence of the reflected wave. Since the switching transistor Q2 is conductive during the period T during which the output of the monostable multi 24 is at the L level, power is supplied to the operation confirmation circuit 3, and the operation confirmation circuit 3 is activated.

When operating normally, the wave receiving transducer 2b receives some kind of reflected wave immediately after turning on the operation switch SW, and receives a reflected wave with a relatively large amplitude. Here, if there is an abnormality such as a failure or disconnection in the oscillation circuit 11 or the transducers 2a and 2b, the intensity of the reflected wave received by the receiving transducer 2b will be much smaller than when it is normal. Therefore, the peak value of the output voltage of the receiving transducer 2b in the normal case is V, the peak value of the output voltage of the receiving transducer 2b in the abnormal case is 2, and the reference voltage Vref of the comparator circuit 31 is V2< If you set Vref and VB, 1. When the mackerel operates normally, the output of the comparator circuit 32 becomes I-level, and when it operates abnormally, the output of the comparator circuit 32 becomes H level. However, in actual operation, the output of the peak value detection circuit 31 is equal to the reference voltage V immediately after the activation switch SW is turned on.
Since ref has not been reached, the output of the comparator circuit 32 becomes I] level immediately after the operation switch SW is turned on, regardless of whether the operation is normal or abnormal.

In the case of normal operation, the receiving transducer 2 is activated for a short time at t111.
Since the peak value V of the output voltage b becomes larger than the reference voltage Vref, the comparator circuit 32 outputs a pulse with a short pulse width tw, as shown in FIG. 2(e). The time constant of the delay circuit 33 is the pulse width tI of this pulse.
It is set larger than II, so that this pulse cannot pass through the delay circuit 3. Therefore, the positive logic output terminal Q of the flip 70 knob 21 is
), while the negative logic output terminal Q maintains the H level as shown in FIG. After , both input terminals of the AND circuit 23 become H level, and the output terminal of the AND circuit @23 becomes H level as shown in FIG. 2(f). In this state, when a reflected wave that satisfies a predetermined condition is received from an object within the detection area, the output of the signal processing circuit 13 becomes U level, so the output of the AND circuit 15 becomes H level, and the notification circuit 14 is activated. That is, if each part is operating normally, when the predetermined time T has elapsed after the operation switch SW is turned on, the power supply to the operation confirmation circuit 3 is stopped and the detection circuit section 1 is activated.

On the other hand, if there is an abnormality in the oscillation circuit 11 or the vibrators 2a and 2b, as shown in the half of FIG.
Since the peak value (2) of the output voltage becomes smaller than the reference voltage Vref of the humpator circuit 32, the output of the delay circuit 33 becomes H level with a slight delay after the activation switch SW is turned on, and an abnormality detection signal is output. As the abnormality detection signal rises, as shown in Fig. 2(d), 7
The positive logic output terminal QfrfI- of the lip 70 and the tube 21 becomes a level, the switching transistor Q1 becomes conductive, and the annunciator 22 is driven. Also, the negative logic output terminal Q1 of the 7-lip 70 tube 21. As shown in Figure 2(e), ■7
level, the operation of the notification circuit 14 of the detection circuit section 1 is prohibited. That is, if there is an abnormality in each part, the abnormality will be detected within a predetermined time T after the activation switch SW is turned on, and the operation of the detection circuit section 1 will be prohibited and the alarm 22 will be driven to detect the abnormality. It is to inform.

As shown in 2, after turning on the operation switch SW, the operation confirmation circuit 3 is operated for a predetermined time T set by the monostable multi 24, and the operation of the detection circuit section 1 is prohibited during this period.
When an abnormality is detected by the operation check circuit 3, the abnormality is notified while the operation of the detection circuit section 1 is prohibited.When the operation check circuit 3 confirms that the operation is normal, the operation check circuit 3 is automatically activated. At the same time, the detection circuit section 1 is activated. Therefore, when the operation switch SW is turned on, the operation is automatically checked, and it is possible to prevent the user from using the device without noticing abnormal operation due to neglecting to check the operation.

[Effects of the Invention 1] As described above, the present invention includes a detection means comprising a transmitting transducer for transmitting ultrasonic waves and a receiving transducer for receiving reflected waves of the ultrasonic waves transmitted from the transmitting transducer; , an operation switch, an operation confirmation means that outputs an abnormality detection signal when an abnormality such as a failure or disconnection of each vibrator is detected, and an operation confirmation circuit that stops the operation of the detection means for a predetermined period of time after turning on the operation switch, and an operation confirmation circuit that outputs an abnormality detection signal for a predetermined period of time after the operation switch is turned on. a time limit means for activating; a notification 11 means for notifying an abnormality when an abnormality detection signal is output from the operation check circuit; a storage means for storing and retaining the output of the operation check circuit; It is equipped with a switching means that activates the detection means when the readout abnormality detection signal is not yet memorized, so when the activation switch is turned on, the operation of the detection means is confirmed internally and the detection 'f' is activated.
- When El is operating normally, the detection means is activated after a predetermined period of time, and if there is an abnormality in the detection means, the abnormality is notified, and as a result, the detection means is activated without the user noticing the abnormality. This has the advantage that this can be prevented. It is particularly effective when used in anti-theft devices and anti-intrusion devices. In addition, when the activation switch is turned on, the operation is first checked and then automatically switched to the detection operation, so operation is easy.Furthermore, since the operation check and detection operation can be performed with just one activation switch, the installation space for the switch is reduced. It is good to have less. Furthermore, since the detection means does not operate for a predetermined period of time after the activation switch is turned on by the time limit means, even if the activation switch is within the detection area, if the operator leaves the detection area within the predetermined time, the operator will be detected. This has the advantage that false alarms can be prevented.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing one embodiment of the present invention, and Fig. 2 is a circuit diagram showing an embodiment of the present invention.
It is an operation|movement explanatory diagram which shows the signal of the content part in the figure. 1 is a detection circuit section, 2a is a transmitting oscillator, 2b is a receiving oscillator, 3 is an operation check circuit, 15 is an AND circuit, 21 is a D7 lip 70 tube circuit, 22 is an alarm, 23 is an AND circuit,
24 is a monostable multi-vibration circuit, SW is an operating switch, and Ql and Q2 are switching transistors.

Claims (1)

[Claims] (1) Failure of the detection means including a transmitting transducer that transmits ultrasonic waves and a receiving transducer that receives reflected waves of the ultrasonic waves transmitted from the transmitting transducer, an activation switch, and each transducer. an operation confirmation means that outputs an abnormality detection signal when detecting an abnormality such as wire breakage or wire breakage; a time limit means that stops the operation of the detection means for a predetermined time after turning on the activation switch and operates an operation confirmation circuit for a predetermined time; Notifying means for notifying an abnormality when an abnormality detection signal is output; storage means for storing and retaining the output of the operation confirmation circuit; and detecting means for reading out the stored contents of the storage means after the expiration of a time limit and detecting when the abnormality detection signal is not stored. An ultrasonic detection device characterized by comprising: switching means for activating.