JPH11248822A - Ultrasonic sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ultrasonic sensor in which a detecting area can be set easily at a desired range irrespective of whether a horn is long or short. SOLUTION: An ultrasonic sensor is provided with a transmission part 10 which transmits an ultrasonic signal, with a reception part 20 which receives the ultrasonic signal reflected by an object M to be detected, with a main control part 80 which detects the existence of the object M, to be detected, on the basis of the ultrasonic signal received by the reception part 20 and with horns 30 in which the transmitting and receiving direction of ultrasonic waves can be set when turned. The ultrasonic sensor is provided with a receiving- output adjusting part 50 which increases or decreases the receiving output of the ultrasonic signal in the reception part 20, with a mode changeover part 60 in which a first transmitting-receiving mode used to detect the object M, to be detected, in a first predetermined detecting area and a second transmitting- receiving mode used to detect the object M, to be detected, in a second detecting area narrower than the first detecting area are changed over and with a reporting part 70 which reports the detecting state of the object M to be detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic sensor having a function of confirming a monitoring range for monitoring an object to be detected.

[0002]

2. Description of the Related Art A conventional ultrasonic sensor will be described with reference to FIG. FIG. 4 is a schematic diagram illustrating a conventional ultrasonic sensor.
(a) shows the case where the horn is long, and (b) shows the case where the horn is short.

The ultrasonic sensor 100 has a transmitting unit 10 for transmitting an ultrasonic signal, a receiving unit 20 for receiving an ultrasonic signal reflected by an object to be detected, and a transmitting / receiving direction of the ultrasonic wave which can be set by rotating. Horn 30. The ultrasonic sensor 100 determines the presence or absence of a detection target based on the ultrasonic signal received by the reception unit 20, and calculates the distance to the detection target by measuring the time between transmission and reception.

When the ultrasonic sensor 100 is mounted on a ceiling or the like, it is necessary to set a detection area for transmitting and receiving an ultrasonic signal. Since the detection area is invisible, the mounting operator replaces the rough setting of the detection area by visually checking whether the horn 30 is oriented in a desired direction. Further, the installation worker checks the detection area in more detail by changing the position of the detection target, and checks whether the detection area has been set in a desired range on the floor surface.

The horn 30 may have a long horn length as shown in FIG. 4A, but if it is desired to improve the appearance,
The horn length is designed to be short as shown in FIG.

[0006]

However, in the conventional ultrasonic sensor as described above, when the horn 30 is shortened, the direction in which the horn 30 is facing becomes difficult to recognize, and when the horn 30 is set, a detection area is set at the time of construction. In addition, it was difficult to identify the range in which the detection area was set. For this reason,
Further, the installation operator needs to operate the ultrasonic sensor 100 to check the detection area while moving the detection target, and check whether the detection area has been set in a desired range on the floor surface. However, since the direction in which the horn 30 is facing is difficult to visually recognize, the ultrasonic sensor 10
Even if 0 detects an object, it is difficult to visually recognize whether the floor position is near the boundary of the detection area or near the center, and it is difficult to set the detection area to a desired range. There was a point.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide an ultrasonic sensor which can easily set a detection area to a desired range regardless of the length of a horn. Is to provide.

[0008]

According to the first aspect of the present invention, a transmitting unit for transmitting an ultrasonic signal, a receiving unit for receiving the ultrasonic signal reflected by an object to be detected, and the receiving unit An ultrasonic sensor comprising: a main control unit that detects the presence of an object to be detected based on the ultrasonic signal received by the horn; and a horn that is capable of setting the direction of transmission and reception of the ultrasonic wave by rotating. A transmission output adjustment unit for increasing or decreasing the transmission output of the ultrasonic signal of the unit, a first transmission / reception mode for detecting an object to be detected in a predetermined first detection area, and a second transmission mode narrower than the first detection area. A mode switching unit for switching between a second transmission / reception mode for detecting an object to be detected in the detection area; and a notifying unit for notifying a detection state of the object to be detected. Is input The said first receive mode second
It is characterized by switching between a transmission mode and a transmission mode.

According to the present invention, a transmitting unit for transmitting an ultrasonic signal, a receiving unit for receiving the ultrasonic signal reflected by an object to be detected, and the ultrasonic wave received by the receiving unit A main control unit that detects the presence of an object to be detected based on a signal, and an ultrasonic sensor including a horn that can set a transmission / reception direction of the ultrasonic wave by rotating, and an ultrasonic signal of the reception unit. A reception output adjusting unit for increasing / decreasing a reception output; a first transmission / reception mode for detecting a detection target in a predetermined first detection area; and a detection target in a second detection area narrower than the first detection area. A mode switching unit for switching between a second transmission / reception mode for detecting an object and a notification unit for notifying a detection state of an object to be detected, wherein the mode switching unit receives an input of a signal indicating operation mode switching. The first transmission and reception And characterized in that for switching the mode between said second receiving mode.

[0010] According to the third aspect of the present invention, the first aspect is provided.
In the ultrasonic sensor described, the transmission output adjustment unit,
In the second transmission / reception mode, the amplification factor of the transmission output of the transmission unit is lower than in the first transmission / reception mode.

According to the fourth aspect of the present invention, there is provided a second aspect.
In the ultrasonic sensor according to the above, the reception output adjustment unit,
The gain of the reception output of the receiving unit is lower in the second transmission / reception mode than in the first transmission / reception mode.

According to the fifth aspect of the present invention, the first aspect is provided.
In the ultrasonic sensor described, the transmission output adjustment unit,
In the first transmission / reception mode, the transmitting unit transmits an ultrasonic signal at a first predetermined oscillation frequency at which the first detection area is obtained, and in the second transmission / reception mode,
The transmitting unit may transmit an ultrasonic signal at a second predetermined oscillation frequency different from the first predetermined oscillation frequency and at which the second detection area is obtained.

According to the sixth aspect of the present invention, there is provided a second aspect.
In the ultrasonic sensor according to the above, the reception output adjustment unit,
In the first transmission / reception mode, only signals of a first predetermined oscillation frequency from which the first detection area is obtained are selected from among the ultrasonic signals emitted from the transmission unit,
In the transmission / reception mode, among the ultrasonic signals emitted from the transmission unit, only signals having a second predetermined oscillation frequency different from the first predetermined oscillation frequency and capable of obtaining the second detection area are selected. It is characterized by.

According to the seventh aspect of the present invention, there is provided the first aspect.
7. The ultrasonic sensor according to any one of claims 6 to 6, wherein the mode switching unit includes a timer, and when the timer finishes measuring a predetermined time after the second transmission / reception mode is started,
The transmission and reception are switched to the first transmission and reception mode.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of an ultrasonic sensor according to the present invention will be described with reference to FIGS.
Will be described in detail with reference to FIG.

[First Embodiment] FIG. 1 is a block diagram illustrating an ultrasonic sensor, and FIG. 2 is a schematic diagram illustrating a detection area of the ultrasonic sensor.

The ultrasonic sensor 100 shown in FIG. 1 includes a transmission unit 10, a reception unit 20, a horn 30, a transmission output adjustment unit 40, a reception output adjustment unit 50, a mode switching unit 60,
It is configured to include a notification unit 70 and a main control unit 80.

The transmitting unit 10 includes a vibrator such as a piezoelectric element, and vibrates the vibrator to transmit an ultrasonic signal when a pulse signal is applied. The receiving unit 20 includes a vibrator such as a piezoelectric element. The receiving unit 20 receives an ultrasonic signal emitted from the transmitting unit 10 and reflected by the detection target M and returned by the vibrator, converts the ultrasonic signal into a pulse signal, and outputs the pulse signal. I do.

The horn 30 is a substantially conical ultrasonic signal guide, is rotatably mounted on a housing (not shown) of the ultrasonic sensor 100, and is capable of setting a transmitting direction and a receiving direction of ultrasonic waves. is there. The horn 30 is attached to, for example, a housing (not shown) of the ultrasonic sensor 100 so as not to protrude from the ultrasonic sensor 100 regardless of rotation. Although two horns 30 are illustrated in FIG. 1, only one horn 30 is actually used, and the horn 30 is used for both the transmission direction control of the transmission unit 10 and the reception direction control of the reception unit 20.

The transmission output adjustment section 40 includes an oscillator 41 and a transmission-side amplifier 42. Oscillator 41
Is a multivibrator circuit including, for example, a transistor and a gate IC.
It oscillates at the oscillation frequency of the ultrasonic signal emitted from. The transmission-side amplifier 42 is an amplifier circuit having frequency characteristics such that the output level corresponding to the oscillation frequency generated by the oscillator 41 has a peak, and after amplifying the signal of the oscillation frequency generated by the oscillator 41, It is provided to the transmission unit 10 as a pulse signal. Such a transmission output adjustment unit 40 includes the transmission-side amplifier 4
The transmission unit 1 is adjusted by adjusting the signal amplification factor in the transmission unit 1.
The transmission output of the ultrasonic signal of 0 is increased or decreased.

The reception output adjustment section 50 includes a first reception-side amplifier 51, a second reception-side amplifier 52, and a first comparator 5
3 and a second comparator 54. The first receiving amplifier 51 and the second receiving amplifier 52 are:
The amplifier circuits are independent and separate from each other, and both are connected to the receiving unit 20 and receive a small pulse signal output from the receiving unit 20. First receiving-side amplifier 51, such as sufficient to detect the detection object M in the first detection area A ₁ to a predetermined, I than the first amplification factor, the pulse signal of the receiver 20 Amplify. The second receiver-side amplifier 52 is configured to detect the object M in the _second detection area A2 which is smaller than the _first detection area A1 with a _second amplification factor. Is amplified. Note that the first detection area A ₁ and the second detection area A ₂ are such that the first detection area A ₁ is a normal detection area and the second detection area A ₂ is inspected at the time of installation. Is the detection area. FIG.
As shown in the figure, the second detection area A ₂ has a spindle shape having a size that just covers the detection target M such as a human body on the floor when viewed from the ceiling when the ultrasonic sensor 100 is attached to the ceiling, for example. The first detection area A ₁ is substantially similar to the _second detection area A _2, and
Accounting for a wider range than the second detection area A _2.

The first comparator 53 stores a first threshold value in advance, and determines whether the value of the amplified output of the first receiving-side amplifier 51 is large based on the first threshold value. judge. When the first comparator 53 determines that the value of the amplified output of the first receiving-side amplifier 51 is larger than the first threshold value, the first comparator 53 outputs a signal indicating that the detection target M is present.

The second comparator 54 stores a second threshold value in advance, and determines whether or not the value of the amplified output of the second receiving amplifier 52 is large with reference to the second threshold value. judge. When the second comparator 54 determines that the value of the amplified output of the second receiving-side amplifier 52 is larger than the second threshold value, the second comparator 54 outputs a signal indicating that the detection target M is present.

In order to receive the pulse signal of the receiving section 20, such a reception output adjusting section 50 includes a route formed by the first receiving side amplifier 51 and the first comparator 53, and a second receiving side amplifier. Two routes, ie, a route by the second comparator 52 and a route by the second comparator 54 are prepared.

The mode switching section 60 is a gate circuit having a timer function as time measuring means.
3 and the second comparator 54, and the first comparator 53
And the output from the second comparator 54 are input. The mode switching unit 60 is also connected to an operation switch 90 which is one push button dedicated to a push operation, for example. The operation switch 90 has a push button portion of the ultrasonic sensor 1
00 so that the ultrasonic sensor 1
Attach to 00.

When the operation switch 90 is pressed, the mode switching section 60 selects the output of the second receiving-side amplifier 52 for a predetermined period of time, passes the output, and outputs the output of the first comparator 53. Does not pass through. When a predetermined time elapses after the operation switch 90 is pressed, the mode switching unit 60 selects the output of the first comparator 53, outputs the selected output, and outputs the output of the second reception-side amplifier 52. Do not output.

The notification section 70 is a lighting circuit section having a display element such as an LED, and is attached to the ultrasonic sensor 100 such that the display portion is exposed on the surface of the housing of the ultrasonic sensor 100.

The main control unit 80 is, for example, a microcomputer having a timer function, and is connected to the oscillator 41, the mode switching unit 60, and the notification unit 70. The main control unit 80 controls the oscillating operation of the oscillator 41, receives an output from the mode switching unit 60, determines the presence / absence of the detection target M, and measures the time between transmission and reception to determine the detection target M. Calculate the distance to. When detecting the detection target M, the main control unit 80 turns on the notification unit 70 to notify the surroundings that the detection of the detection target M is detected.

The ultrasonic sensor 100 constructed as described above
Is mode up switching unit 60 is depressed, as shown in FIG. 2, to detect the detection object M such as a human body in the first detection area A ₁ to a predetermined (first transceiver mode), Mode When the switching unit 60 is depressed, thereby to detect the detection object M in the first detection area a second detection area a ₂ narrower than ₁ (second reception mode).

That is, the operator of the ultrasonic sensor 100 is required to set the first detection area A ₁ during construction.
Short horn 30, if Katakere distinguish whether the direction facing the horn 30 is set to the hard and detection area A ₁ is which range found to, press the mode switching part 60, narrower than the first detection area A ₁ Put the second detection area a _2, while watching the notification unit 70 to adjust the orientation of the horn 30. That is, the installation worker previously arranges the detection target M substantially at the center of the desired area on the floor surface where the detection area is desired to be extended. Then, the mounting operator adjusts the direction of the horn 30 until the notification unit 70 is turned on. The installation operator visually confirms the lighting of the notification unit 70, and then determines the horn 3 at that time.
It can be determined that the direction of 0 is substantially facing the detection target M.
In other words, the mounting operator has been able to direct the horn 30 to substantially the center of the desired range in which the detection area is desired to be extended. Therefore, the installation operator can use the mode switching unit 60.
If you wait until the timer expires, the detection area can be set wide from the second detection area A ₂ in the first detection area A _1, moreover a first range occupied by the detection area A _1,
It is confirmed as a range including the position of the detection object M of using a second detection area A _2.

Therefore, the ultrasonic sensor 100 is
Reception output adjusting unit 5 for increasing or decreasing the reception output of the ultrasonic signal of 0
0, the first first transceiver mode in detection area A ₁ detects the detection object M and the first detection area A ₁ to a predetermined
A mode switching unit 60 for switching and a second receive mode to detect the detection object M in the second detection area A ₂ narrower than, the notification unit 7 for displaying notification detection state of the detection object M
The reception output adjustment unit 50 operates in the first transmission / reception mode during normal human body detection, and a signal to the effect that the operation mode has been switched to the second transmission / reception mode is given to the mode switching unit 60. In the second transmission / reception mode, even if the horn 30 is shortened, the detection target M is first positioned substantially at the center of the desired detection range, and the detection target M is set in the second transmission / reception mode. by adjusting the orientation of the horn 30 until detection, easy to understand a first center position and the range of detection area a ₁ when returning the operation mode to the first transceiver mode, the first detection area a ₁ It is easy to set a desired range.

Further, the reception output adjusting section 50 performs the following operations in the second transmission / reception mode compared to the first transmission / reception mode.
If an amplifier capable of adjusting the amplification factor is used in order to lower the amplification factor of the reception output of the reception unit 20, the reception output adjustment unit 50 can be realized with a simple configuration.

The mode switching section 60 is a gate circuit having a timer function as a time measuring means. When the time measuring means finishes measuring a predetermined time from the start of the second transmission / reception mode, the first transmission / reception is performed. Since the mode is switched to the transmission / reception in the mode, for example, when a predetermined time elapses, the mode switching unit 60 is manually operated to switch the transmission / reception in the first transmission / reception mode. In addition, there is no fear of forgetting to switch to the first transmission / reception mode, and workability is improved.

In the above embodiment, the switching between the _first detection area A ₁ and the second detection area A ₂ is performed by the first reception side amplifier 51 of the reception output adjustment section 50 and the first reception area A ₁ .
Although an example in which the selection is performed by selecting the second reception-side amplifier 52 has been described, the present invention is not limited to this.
An amplifier having a low amplification rate is selectively added in a switchable manner until the second detection area is obtained, and the transmission output adjustment unit is configured to perform the transmission power adjustment in the second transmission / reception mode rather than in the first transmission / reception mode. In this case, the amplification factor of the transmission output of the transmission unit may be lowered, and the first detection is performed by combining the increase / decrease of the amplification factor of the transmission output adjustment unit and the increase / decrease of the amplification factor of the reception output adjustment unit. The area and the second detection area may be obtained.

In the above-described embodiment, the mode switching section 60 has a timer function, and when the predetermined time has elapsed after the second transmission / reception mode has been started, the operation mode is switched to the first transmission / reception mode. However, the present invention is not limited to this. The mode switching unit is provided as a changeover switch connected to the main control unit, and the main control unit is provided with a first comparator and a first comparator. The second comparator is directly supplied with each output, and the main control unit switches between the first transmission / reception mode and the second transmission / reception mode in accordance with the mode switching unit, that is, by manual operation of the mode switching unit. Thus, the first transmission / reception mode and the second transmission / reception mode may be switched.

In the above embodiment, the notification unit 70 is a lighting circuit unit having a display element such as an LED, which displays and notifies the detection state of the detection target M. The present invention is not limited to this, and the notifying unit may notify the detection state of the detected object by a notifying sound such as a buzzer sound or a recording sound. [Second Embodiment] FIG. 3 is a block diagram illustrating an ultrasonic sensor. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description of the same parts will be omitted.

The ultrasonic sensor according to the second embodiment is different from the ultrasonic sensor according to the first embodiment in that the switching between the first transmission / reception mode and the second transmission / reception mode is transmitted. In this configuration, the adjustment is not performed by adjusting the amplification factor of the output adjustment unit or the reception output adjustment unit, but by adjusting the transmission / reception frequency of the ultrasonic signal.

The transmission output adjustment section 40 includes a transmission-side amplifier 42
, A first oscillator 43 and a second oscillator 44. A first oscillator 43 and a second oscillator 4
4 are, for example, the oscillators 4 of the first embodiment, respectively.
Like the first embodiment, the multivibrator circuit includes a transistor, a gate IC, and the like. The first oscillator 43 is a first predetermined oscillation frequency f ₁ of the first detection area A ₁ is obtained is stored in advance, vibrating at the first predetermined oscillation frequency f _1. Second oscillator 44, a second detection area A ₂ is the second predetermined oscillation frequency f ₂ obtained is stored in advance, oscillating at the second predetermined oscillation frequency f _2.

The transmission-side amplifier 42 is an amplifier circuit, and is connected to a first oscillator 43 and a second oscillator 44, and generates a first predetermined oscillation frequency f ₁ generated by the first oscillator 43. And the signal of the second predetermined oscillation frequency f ₂ generated by the second oscillator 44 are input and amplified and output to the transmission unit 10.

When transmitting a pulse signal to the transmission unit 10, the transmission output adjustment unit 40 controls the first predetermined oscillation frequency f ₁ of the first oscillator 43 and the second predetermined oscillation frequency f ₁ of the second oscillator 44. _Two oscillation frequencies, that is, a predetermined oscillation frequency f2, can be prepared.

The reception output adjustment section 50 includes a first reception-side amplifier 51 and a first comparator 53. The first receiving-side amplifier 51 is an amplifier circuit,
A small pulse signal output from the receiving unit 20 is input by being connected to the receiving unit 20.

The first comparator 53 stores a first threshold value in advance, and determines whether or not the value of the amplified output of the first receiving-side amplifier 51 is large with reference to the first threshold value. judge. When the first comparator 53 determines that the value of the amplified output of the first receiving-side amplifier 51 is larger than the first threshold value,
The main controller 80 sends a signal indicating the presence of the object M to be detected.
Output to

The mode switching section 60 is a gate circuit having a timer function as time measuring means.
3, the second oscillator 44, the main control unit 80, and the operation switch 90.

When the operation switch 90 is pressed, the mode switching unit 60 connects the output of the main control unit 80 to the second oscillator 44 for a predetermined time after the operation switch 90 is pressed, The output of the second oscillator 44 is selected and passed and output, and the output of the first oscillator 43 is not passed and output. When a predetermined time has elapsed since the operation switch 90 was pressed, the mode switching unit 60 connects the output of the main control unit 80 to the first oscillator 43, selects the output of the first oscillator 43, and While passing through, the output of the second oscillator 44 is not passed through.

Therefore, the ultrasonic sensor 100 includes the transmitting unit 1
Transmission output adjusting unit 4 for increasing or decreasing the transmission output of the ultrasonic signal of 0
0, the first first transceiver mode in detection area A ₁ detects the detection object M and the first detection area A ₁ to a predetermined
A mode switching unit 60 for switching and a second receive mode to detect the detection object M in the second detection area A ₂ narrower than, the notification unit 7 for displaying notification detection state of the detection object M
The transmission output adjustment unit 40 operates in the first transmission / reception mode during normal human body detection, and a signal to the effect that the operation mode has been switched to the second transmission / reception mode is given to the mode switching unit 60. In the second transmission / reception mode, even if the horn 30 is shortened, the detection target M is first positioned substantially at the center of the desired detection range, and the detection target M is set in the second transmission / reception mode. by adjusting the orientation of the horn 30 until detection, easy to understand a first center position and the range of detection area a ₁ when returning the operation mode to the first transceiver mode, the first detection area a ₁ It is easy to set a desired range.

In the first transmission / reception mode, the transmission output adjusting section 40 transmits an ultrasonic signal to the transmitting section 10 at the first predetermined oscillation frequency f ₁ at which the first detection area A ₁ is obtained. In the second transmission / reception mode, the transmitting unit 10
The ultrasonic signal is converted to a second predetermined oscillation frequency f ₂ which is different from the _first predetermined oscillation frequency f ₁ and in which a second detection area A ₂ is obtained.
₂ , the transmission output adjusting unit 4
0 can be easily realized by the frequency control method.

The mode switching section 60 is a gate circuit having a timer function as a time measuring means. When the time measuring means finishes measuring a predetermined time from the start of the second transmission / reception mode, the first transmission / reception is performed. Since the mode is switched to the transmission / reception in the mode, for example, when a predetermined time elapses, the mode switching unit 60 is manually operated to switch the transmission / reception in the first transmission / reception mode. In addition, there is no fear of forgetting to switch to the first transmission / reception mode, and workability is improved.

In the above embodiment, the switching between the _first detection area A ₁ and the second detection area A ₂ is performed by the first oscillator 43 and the second oscillator 44 of the transmission output adjusting unit 40. However, the present invention is not limited to this, and the reception output adjustment unit may have a filter function of selecting only a signal of the second predetermined oscillation frequency. The first detection area and the second detection area may be obtained by using both the oscillation of the second predetermined oscillation frequency of the adjustment unit and the filter of the reception output adjustment unit.

In the above embodiment, the mode switching section 60 has a timer function, and when the predetermined time has elapsed after the start of the second transmission / reception mode, the operation mode is changed to the first transmission / reception mode. However, the present invention is not limited to this, and the mode switching unit is provided as a changeover switch connected to the main control unit, and the main control unit includes the first oscillator and the first oscillator. And the main control unit switches between the first transmission / reception mode and the second transmission / reception mode according to the mode switching unit, that is, the first transmission / reception mode is manually operated by the mode switching unit. And the second transmission / reception mode.

In the above-described embodiment, the notification unit 70 is a lighting circuit unit having a display element such as an LED, which displays and notifies the detection state of the detection target M. The present invention is not limited to this, and the notifying unit may notify the detection state of the detected object by a notifying sound such as a buzzer sound or a recording sound.

[0051]

According to the first aspect of the present invention, the ultrasonic sensor includes a transmission output adjusting unit for increasing or decreasing the transmission output of the ultrasonic signal from the transmitting unit, and a transmission output adjusting unit configured to receive the ultrasonic signal in a predetermined first detection area. A first transmission / reception mode for detecting an object and a second mode for detecting an object in a second detection area smaller than the first detection area.
It has a mode switching unit for switching between the transmission and reception modes, and a notification unit for notifying the detection state of the detected object. Since the transmission / reception mode is switched between the transmission / reception mode and the second transmission / reception mode, even if the horn becomes short, the detection target is first positioned substantially at the center of the desired detection range, and the detection target is detected in the second transmission / reception mode. If the direction of the horn is adjusted until the operation mode is changed, the center position and the range of the first detection area when the operation mode is returned to the first transmission / reception mode can be easily understood, and the first detection area can be easily set to a desired range. .

According to the second aspect of the present invention, a reception output adjusting section for increasing or decreasing the reception output of the ultrasonic signal of the reception section, and a first detection section for detecting an object in a predetermined first detection area. A mode switching unit for switching between a transmission / reception mode and a second transmission / reception mode for detecting an object in a second detection area smaller than the first detection area; and a notification unit for notifying a detection state of the object. The mode switching unit switches between the first transmission / reception mode and the second transmission / reception mode when a signal indicating the operation mode switching is input, so that even if the horn becomes short, If the object is positioned substantially at the center of the desired detection range and the direction of the horn is adjusted until the object is detected in the second transmission / reception mode, the first mode when the operation mode is returned to the first transmission / reception mode is obtained.
The center position and range of the detection area can be easily understood, and the first detection area can be easily set to a desired range.

In the invention according to claim 3, claim 1
In addition to the effects of the invention described above, the transmission output adjusting section lowers the amplification factor of the transmission output of the transmission section in the second transmission / reception mode than in the first transmission / reception mode. If a possible amplifier is used, the transmission output adjustment unit can be realized with a simple configuration.

According to the fourth aspect of the present invention, a second aspect is provided.
In addition to the effects of the invention described above, the reception output adjustment unit lowers the gain of the reception output of the reception unit in the second transmission / reception mode than in the first transmission / reception mode. If a possible amplifier is used, the reception output adjustment unit can be realized with a simple configuration.

In the invention according to claim 5, claim 1 is
In addition to the effects of the invention described, the transmission output adjustment unit causes the transmission unit to transmit the ultrasonic signal at the first predetermined oscillation frequency at which the first detection area is obtained, in the first transmission / reception mode, In the second transmission / reception mode, the transmission unit is caused to transmit the ultrasonic signal at the second predetermined oscillation frequency different from the first predetermined oscillation frequency so as to obtain the second detection area. The unit can be easily realized by a frequency control method.

According to the sixth aspect of the present invention, there is provided a second aspect.
In addition to the effects of the invention described above, the reception output adjustment unit is configured to output a signal of the first predetermined oscillation frequency from which the first detection area is obtained, among the ultrasonic signals emitted from the transmission unit in the first transmission / reception mode. Only in the second transmission / reception mode,
Of the ultrasonic signals emitted from the transmission unit, unlike the first predetermined oscillation frequency, only the signal of the second predetermined oscillation frequency from which the second detection area is obtained is selected,
The reception output adjusting unit can be easily realized by the frequency control method.

According to the seventh aspect of the present invention, there is provided the first aspect.
In addition to the effects of the inventions described in the above-described embodiments, the mode switching unit includes a timer, and when the timer finishes measuring a predetermined time from the start of the second transmission / reception mode, the transmission / reception in the first transmission / reception mode is completed. For example, as compared with an ultrasonic sensor having a configuration that requires a manual operation of the mode switching unit to switch to transmission and reception in the first transmission / reception mode after a predetermined time has elapsed, the first switching is performed. There is no risk of forgetting to switch to transmission / reception mode,
Workability is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an ultrasonic sensor according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating a detection area of the ultrasonic sensor according to the first embodiment.

FIG. 3 is a block diagram illustrating an ultrasonic sensor according to a second embodiment of the present invention.

FIG. 4 is a schematic diagram illustrating a conventional ultrasonic sensor.

[Explanation of symbols]

Reference Signs List 10 transmitting unit 20 receiving unit 30 horn 40 transmission output adjusting unit 50 reception output adjusting unit 60 mode switching unit 70 notification unit 80 main control unit M object to be detected A1 _first detection area A2 _second detection area f1 _first 1 predetermined oscillation frequency f ₂ second predetermined oscillation frequency

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masatake Uno 1048 Odakadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works, Ltd.

Claims (7)

[Claims] A transmitting unit that transmits an ultrasonic signal; a receiving unit that receives the ultrasonic signal reflected by the object; and a detecting unit that detects the ultrasonic signal based on the ultrasonic signal received by the receiving unit. In an ultrasonic sensor including a main control unit that detects the presence and a horn that can set the transmission and reception direction of the ultrasonic wave by rotating, a transmission output adjustment unit that increases and decreases the transmission output of the ultrasonic signal of the transmission unit. A first transmission / reception mode for detecting an object in a predetermined first detection area;
A mode switching unit for switching between a second transmission / reception mode for detecting an object to be detected in a second detection area narrower than the detection area, and a notifying unit for notifying a detection state of the object to be detected. The ultrasonic sensor according to claim 1, wherein the mode switching unit switches between the first transmission / reception mode and the second transmission / reception mode when a signal for switching the operation mode is input. 2. A transmitting section for transmitting an ultrasonic signal, a receiving section for receiving the ultrasonic signal reflected by the object, and a detecting section for the object based on the ultrasonic signal received by the receiving section. In an ultrasonic sensor including a main control unit that detects the presence and a horn that can set the transmission and reception direction of the ultrasonic wave by rotating, a reception output adjustment unit that increases and decreases the reception output of the ultrasonic signal of the reception unit A first transmission / reception mode for detecting an object in a predetermined first detection area;
A mode switching unit for switching between a second transmission / reception mode for detecting an object to be detected in a second detection area narrower than the detection area, and a notifying unit for notifying a detection state of the object to be detected. The ultrasonic sensor according to claim 1, wherein the mode switching unit switches between the first transmission / reception mode and the second transmission / reception mode when a signal for switching the operation mode is input. 3. The transmission output adjusting unit according to claim 2, wherein the transmission output gain of the transmission unit is lower in the second transmission / reception mode than in the first transmission / reception mode. 2. The ultrasonic sensor according to 1. 4. The reception output adjustment unit according to claim 1, wherein the reception output gain of the reception unit is lower in the second transmission / reception mode than in the first transmission / reception mode. 2. The ultrasonic sensor according to 2. 5. The transmission output adjustment unit, when in the first transmission / reception mode, causes the transmission unit to transmit an ultrasonic signal at a first predetermined oscillation frequency at which the first detection area is obtained, In the second transmission / reception mode, the transmitting unit includes:
The ultrasonic sensor according to claim 1, wherein the ultrasonic signal is transmitted at a second predetermined oscillation frequency different from the first predetermined oscillation frequency and at which the second detection area is obtained. 6. The reception output adjustment section, among the ultrasonic signals emitted from the transmission section in the first transmission / reception mode, a signal having a first predetermined oscillation frequency for obtaining the first detection area. Only the selected, in the second transmission and reception mode, among the ultrasonic signals emitted from the transmission unit,
3. The ultrasonic sensor according to claim 2, wherein, different from the first predetermined oscillation frequency, only a signal having a second predetermined oscillation frequency at which the second detection area is obtained is selected. 7. The mode switching unit includes a timing unit,
7. The ultrasonic wave according to claim 1, wherein when the timer measures a predetermined time after the start of the second transmission / reception mode, it switches to transmission / reception in the first transmission / reception mode. Sensor.