Patent Translate Powered by EPO and Google Notice This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate, complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or financial decisions, should not be based on machine-translation output. DESCRIPTION JPS61155975 [0001] FIELD OF THE INVENTION The present invention relates to an ultrasonic sensor comprising an ultrasonic transmission sensor for transmitting ultrasonic waves and an ultrasonic reception sensor for receiving reflected waves from an object, and in particular to the beam width of its directivity pattern. It relates to the technology to spread. Prior Art A conventional ultrasonic sensor in an ultrasonic moving object detector for detecting the presence or absence of a moving object using the Doppler effect of ultrasonic waves is an ultrasonic wave transmitting surface of an ultrasonic wave transmission sensor and an ultrasonic wave receiving sensor. Directionality in a plane parallel to a perpendicular bisector of a line connecting the center of the ultrasonic wave transmitting surface and the center of the ultrasonic wave receiving surface, with the ultrasonic wave receiving surface being disposed away from the ultrasonic wave receiving surface by a predetermined length The main beam width of the pattern is narrow. For this reason, the angle desired from the ultrasonic sensor is narrow (it was suitable for home use, but not suitable for automobile which must be monitored over a wide angle. That is, when an ultrasonic moving object detector is attached to a car in order to protect equipment such as radios, cassette decks, radios and the like installed in the car from the car, generally, for example, as shown in FIG. The ultrasonic sensor 2 is mounted near the rearview mirror in the passenger compartment ceiling, but since the main beam width is as narrow as α °, only the inside of the car and the rear window 3 and part of the side window 4 can be monitored with a good S / N ratio. Can not. Of course, if the ultrasonic sensor is driven with a large transmission power and a sufficient S / N ratio is obtained, the side beam 4 can be covered by the sub beam, but the power consumption becomes extremely large and the cause of the battery upset. Become. 18 o to fully cover the side window. Although some beam widths are required, none of the commercially available ultrasonic sensors have such directivity. The problem to be solved by the invention The present invention has been made in view of such circumstances, and its object is to expand the beam width of an 03-05-2019 1 ultrasonic sensor with a simple configuration. Means for Solving the Problems When the present invention is applied to an automobile, the distance from the ultrasonic sensor is about 1 to 2 m for detecting an intruder, so that a sufficiently small reception level is obtained even if the gain is somewhat small. In view of the above, the beam width can be expanded by dispersing part of the energy in the conventional main beam to the left and right, so that both movement of a person in the vehicle compartment and breakage of a side window can be detected. The ultrasonic wave transmission sensor transmits an ultrasonic wave, the ultrasonic wave reception sensor receives a reflected wave from an object, and detects the presence or absence of a moving object based on the beat signal of the reception signal and the transmission signal. In an ultrasonic sensor for a moving object detector, on the ultrasonic wave transmitting surface of an ultrasonic wave transmitting sensor and an ultrasonic wave receiving surface of an ultrasonic wave receiving sensor, a part of ultrasonic waves from the ultrasonic wave transmitting surface is one of Turn to the side And a first surface for guiding a part forward by diffraction, and a second surface for reflecting a part of the ultrasonic wave from the ultrasonic wave transmitting surface to the other side and guiding a part forward by diffraction. A third surface for reflecting a reflected wave from one side to be incident on the ultrasonic receiving surface and causing a reflected wave from the front to be incident on the ultrasonic receiving surface by diffraction, and the other surface from the other side A reflection / diffraction plate is provided having a fourth surface which reflects the reflected wave and makes it incident on the ultrasonic wave receiving surface and causes the reflected wave from the front to be incident on the ultrasonic wave receiving surface by diffraction. The four surfaces may be flat as shown in the embodiments described later, or may be surfaces having some unevenness. In the preferred embodiment, the first and third surfaces are comprised of the same surface, and the second and fourth surfaces are also comprised of the same surface, but may be separate surfaces. The ultrasonic waves transmitted from the active ultrasonic wave transmission sensor are partially reflected to both sides of the sensor by the reflection and diffraction plate and diffracted and transmitted to the front of the sensor from the both sides of the sensor. The incoming reflected wave is reflected by the reflection and diffraction plate and is incident on the receiving surface of the ultrasonic wave receiving sensor, and the reflected wave coming from the front of the sensor is incident on the receiving surface of the ultrasonic wave receiving sensor by diffraction. The beam width of the directivity pattern of the plane parallel to the perpendicular bisector of the line connecting the center of the plane and the center of the reception plane is expanded compared to the prior art. Embodiment A trust sensor 12 is an ultrasonic wave receiving sensor. The ultrasonic wave transmission sensor 11 is driven by a pulse from a pulse oscillation circuit (not shown) to transmit ultrasonic waves from the ultrasonic wave transmission surface 11a, and the ultrasonic wave reception sensor 12 uses an ultrasonic wave reception surface 12a. When an ultrasonic wave is incident, it is converted into an electric signal and output, and the two are arranged at a predetermined interval so that the transmitting surface 11a and the receiving surface 12a are positioned substantially in the 03-05-2019 2 same plane. On the ultrasonic wave transmitting surface 11a and the ultrasonic wave receiving surface 12a, a V-shaped reflection / diffraction plate 10 made of a hard material such as plastic or metal capable of sufficiently reflecting ultrasonic waves is bent at its central portion Are measured by a measuring system which is extracted by a support machine filter 54 (not shown) so as to be almost directly above the delivery surface 11a and the receiving surface 12a and amplified by an amplifier 55. In addition, for comparison, the directivity pattern in a state where the reflection and diffraction plate was removed was measured by the same measurement system. The solid line in FIG. 4 shows this. As can be seen from FIG. 4, without the reflective / diffraction plate 30, the gain is extremely reduced at angles of + 50 ° or more and -50 ° or less, and the beam width is narrowed. On the other hand, when the reflection and diffraction plate 30 is provided, sufficient gain is obtained over a wide range of 180 ° or more, and the beam width is expanded. FIG. 6 shows an embodiment in which the ultrasonic wave sensor of the present invention is applied to an antitheft device for a car, 40 is an ultrasonic moving object detector, 41 is a microcomputer, 42 is a car battery, 44 is an AND circuit, 6 Is an alarm. The ultrasonic moving object detector 40 includes a pulse oscillation circuit 60, an ultrasonic transmission sensor 32 to which this pulse is applied, a reflection and diffraction plate 30. The ultrasonic wave sensor 50 comprising the ultrasonic wave reception sensor 33, the mixing circuit 61 for mixing the output of the ultrasonic wave reception sensor 33 and the output of the pulse oscillation circuit 60, and the beat component extracted from the output of the mixing circuit 62 A band pass filter 62, an amplifier 63 for amplifying the output of the band pass filter 62, and a comparison circuit 65 for obtaining a single reference voltage V obtained by dividing the voltage Vcc by the resistor 64 using the output of the amplifier 63 as ten power. And a level integrating circuit 66 which performs level integration on the output of the comparison circuit @ 65, and a waveform shaping circuit which shapes the output of the level integrating circuit 66 into a rectangular wave. The ultrasonic sensor 50 is mounted, for example, in the vicinity of a rearview mirror on the ceiling of a passenger compartment of a car. The microcomputer 41 is a so-called one-chip microcomputer including a ROM, a RAM, etc., and receives an ignition switch state signal, an open / close state signal of a car door, and an output signal a of the waveform shaping circuit 67 as input. A start signal and an open / close signal of the AND circuit 45 are generated. The constant voltage circuit 43 converts the voltage of the car battery 42 to a constant voltage to generate a voltage cc and supplies it to each part of the ultrasonic moving object detector. FIG. 7 is a flow chart showing an example of processing performed by the microcomputer 41. マイクロコンピュータ41はイグニッションスイッチのオン。 If the ignition switch status signal determines that it has been turned off, as shown in FIG. 7, the signal is first made "θ" to close the AND circuit 44 (Sl>, constant voltage The circuit 43 is activated to activate the ultrasonic moving object detector (S2). As a result, a pulse is applied from the pulse oscillation circuit 60 to the ultrasonic transmission sensor 32, and transmission of ultrasonic waves is performed. Because the beam width of the ultrasonic sensor 50 is wide, the ultrasonic waves are sufficiently input not only to the rear window but also to the side windows, and the 03-05-2019 3 reflected ultrasonic waves are input to the ultrasonic wave receiving sensor 33. The microcomputer 41 then reads the door open / close state signal to determine whether all the doors are closed or not S3). When the doors are all closed, the output a of the waveform shaping circuit 67 is for a predetermined time, for example, several seconds to several tens seconds It is determined whether it is "0" (S4). そして、ステップS3. When the condition of S4 is satisfied, the AND circuit 44 is opened with the signal at the position so that the alarm 5 can be activated by the output a of the ultrasonic moving object detector (S5). Such control is performed so that the essential operation of the car antitheft device is performed after the person in the car turns off the ignition switch and closes all the down doors from the car. When there is no abnormality in the window glass or the like, the beat signal becomes almost zero, so the output voltage of the amplifier 63 is smaller than that of the reference voltage section 7 and the output a of the waveform shaping circuit 67 is "0". However, if the window glass is strongly struck or broken, a beat signal is generated due to vibration of the window glass or a broken glass piece etc., and the output voltage of the amplifier 63 becomes larger than the reference voltage 3 and the waveform shaping circuit The output a of 67 becomes "1". As a result, the alarm 45 operates and an alarm is issued. As the alarm 45, a horn circuit of a car can be used. The microcomputer 41 monitors the door open / close state signal after the ultrasonic moving object detector 40 is properly activated as shown in FIG. 7 (S6), and when any door is opened, the constant voltage is maintained. The operation of the circuit 43 is stopped and the operation of the ultrasonic moving object detector 40 is stopped (S7). This is to prevent the driver or the like from issuing a false alarm when the door is opened and the vehicle enters. FIG. 6 shows that the ultrasonic sensor according to the present invention is used as an antitheft device for a car, but the ultrasonic sensor 50 can be applied to the detection of moving objects in a bank of a car by attaching the ultrasonic sensor 50 to the rear of the car. It can also be applied to home use. As described in detail in the invention, the present invention is provided with a reflection and diffraction plate in front of an ultrasonic wave transmission sensor and an ultrasonic wave reception sensor, and the beam width of the directional pulse can be expanded compared to the prior art. effective. Therefore, it is suitable for an ultrasonic mobile object detector for automobiles that must be monitored over a wide angle. Further, since the wavelength of the ultrasonic wave is very short and the dimension of the reflection and diffraction plate is correspondingly small, the mounting property to an automobile or the like is also good. [0002] Brief description of the drawings [0003] 03-05-2019 4 1 is a schematic diagram of the embodiment of the present invention, FIG. 2 is a side view thereof, FIG. 3 is an external perspective view of another embodiment of the present invention, and FIG. 4 is a directivity pattern of the embodiment of the present invention. (Dotted line) and a diagram showing the directivity pattern (solid line) of the conventional example, FIG. 5 is a block diagram showing a measurement system of the directivity pattern, and FIG. 6 is an antitheft vehicle for automobile using the ultrasonic sensor of the present invention. FIG. 7 is a block diagram of an embodiment of the apparatus, FIG. 7 is a flowchart showing an example of processing of the microcomputer 41, and FIG. 8 is an explanatory view of a conventional problem. 10.30 is a reflection and diffraction plate, 11.32 is an ultrasonic wave transmission sensor, and 12.33 is an ultrasonic wave reception sensor. 03-05-2019 5
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