JPS5832336Y2 - ultrasonic solid state retarder - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an ultrasonic solid-state retarder with improved frequency response and miniaturization.

As shown in FIG. 1, this type of delay element has two input transducers 2 and 3 with mutually different passing frequency bands at one end of the same delay medium 1, and the aforementioned two input transducers 2 and 3 at the other end of this delay medium 1. It is known that two output transducers 2' and 3' corresponding to individual human transducers 2 and 3 are arranged side by side.

Regarding the other symbols in the figure, 4 is an input signal, 5 is a tuning resistor, 6 is a tuning coil, and 7 is a load resistor.

Such a delay element uses the same delay medium 1, but the propagation path 8 of the delay element consisting of the input/output converters 2 and 2'
and a delay element propagation path 9 consisting of input/output converters 3 and 3'.
-They seem to be the same at first glance, but regarding the passing frequency of both delay elements, one has a low frequency,
It is not possible to match the delay times due to propagation paths 8 and 9 since the other one is chosen to be of high frequency.

More specifically, the ultrasonic sound velocity within the transducer is 2000 to 3500 m/s when a commonly used piezoelectric material such as piezoelectric ceramics or crystal is used for the transducer, and the thickness of the transducer is 0.5 m/s. Even if it is assumed to be in the range of 0.05 to 1 mm,
Since the delay time within the transducer ranges from about 13 to 500 ns, the delay time differs by the difference in thickness of the transducer.

This kind of delay time mismatch is caused by input/output converter 2.2'
Also, a shift in the output phase of both delay elements due to 3 and 3' is inevitably generated.

- In addition to the above drawbacks, the delay element shown in Figure 1 has two sets of transducers installed in parallel, so the width dimension of the delay medium must be doubled, which is especially important for SH waves. In a delay element using a transducer, the installation area of the transducer is limited, so the area of the transducer must be made small, resulting in a decrease in output.

The present invention was made with the aim of eliminating the above-mentioned drawbacks, and includes a plurality of input transducers with different frequency bands installed at one end of a delay medium forming a predetermined propagation path, and a plurality of input transducers with different frequency bands. A plurality of output transducers corresponding to the input transducer installed at the other end are installed so as to be stacked oppositely to each other when viewed from the installation surface on the delay medium side. It is a sonic solid state retarder.

FIG. 2 is a schematic diagram of an ultrasonic solid state retarder showing an embodiment of the present invention.

At both ends of the delay medium 10, the main surface of an input transducer 12 is installed on the delay medium 10 by adhesive at the input end, and another manual transducer 11 is installed on the other main surface of the input transducer 12. At the output end, the main surface of the output transducer 11' corresponding to the input transducer 11 is installed on the delay medium 10 by adhesion, and on the other main surface of the output transducer 11'. An output transducer 12' corresponding to the input transducer 12 is installed by gluing, resulting in an input/output transducer 11.12.11'.

12' are installed so as to be stacked in reverse when viewed from the installation surface on the delay medium 10 side.

Therefore, the sound wave emitted from the input transducer 11 propagates along the propagation path 13 through the input transducer 12 and the delay medium 10, reaches the output transducer 11', and reaches the input transducer 12.
The sound waves emitted from the delay medium 10 and the output transducer 11'
and propagates along propagation path 14 through output transducer 12
′ is reached.

Although the propagation paths 13 and 14 are shown slightly shifted in parallel in order to clarify the emission and arrival points, they are actually on the same line.

Regarding the connection of the external circuit, a connection line 15 is connected from the electrode provided on the installation surface of the delay medium 10 of the input transducer 12, a connection line 16 is connected from the electrode provided on both the installation surfaces of the input transducers 11 and 12, and the input The connecting wires 17 are drawn out from the electrodes provided on the other main surface of the transducer 11 (in this example, the outermost main surface), and the connecting wires 15 and 17 are connected, and the connecting wire 16 is connected to the two terminals. , are connected to an input signal 4, a tuning resistor 5, and a tuning coil 6 as shown in FIG.

Such a connection also applies to connection lines 18 and 19 on the output side.
and 20 are similarly performed.

Thus, each passing frequency band of the frequency f□ of the human output transducer 11.11' and the frequency f2 of the input/output transducer 12.12' appears as a curve 21 and a curve 22 as shown in FIG. These pass frequency bands are combined to obtain the pass band indicated by diagonal lines in the figure.

Since the propagation paths 13 and 14 are on the same path and are equidistant, the frequency response of the passband resulting from this synthesis is determined by the delay element by the input/output converter 11° 11' and the input/output converter 12. It is possible to completely match each output phase of the delay element by .12', and distortion-free characteristics can be obtained.

Since the output phases are combined on the same propagation path, this fine adjustment of the output phase can be easily performed by an external additional circuit as in the case of a single delay element.

Furthermore, according to the present invention, since the transducer installation structure is stacked and bonded, even if the number of stacks is increased, the external dimensions of the delay medium using one set of input/output transducers remain the same and can be made smaller. can be maintained.

This advantage is particularly useful in SH wave based delay elements where the transducer footprint is limited.

FIG. 4 shows an example in which the present invention is used in a polygonal delay medium 23. The configuration and effects of this example are those of the example shown in FIG. 2 except for the shielding medium 23. It is similar to

Although the present invention has been described above in its embodiments with two stacked structures, it is of course possible to have a stacked structure of three or more.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a conventional ultrasonic solid retarder, Fig. 2 is a schematic diagram of an ultrasonic solid retarder which is an embodiment of the present invention, and Fig. 3 is a schematic diagram of an ultrasonic solid retarder that is an embodiment of the present invention.
The figure is a frequency response characteristic diagram of the embodiment shown in both figures.
The figure is a schematic diagram of an ultrasonic solid state retarder when the present invention is used in a polygonal retardation medium. 10.23... Delay medium, 11.12...
...Input converter, 11'. 12'...Output converter.

Claims (1)

[Scope of utility model registration request] A plurality of manual transducers having different frequency bands are installed at one end of a delay medium forming a predetermined propagation path, and a plurality of outputs corresponding to the input transducers are installed at the other end of the delay medium. 1. An ultrasonic solid-state retardator, characterized in that the transducers are installed so as to be stacked on top of each other in reverse when viewed from the installation surface on the delay medium side.