JPH04408B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an ultrasonic delay line used in televisions, VTRs, etc.

Conventional configurations and their problems In recent years, ultrasonic delay lines have been used in televisions, VTRs, etc., but there is a growing demand for further miniaturization.

A conventional ultrasonic delay line uses glass as a delay medium to obtain delay characteristics by propagating a delay signal emitted from a piezoelectric transducer as a bulk wave within the glass.

However, with the above configuration, it has been difficult to make it smaller than the current shape.

OBJECTS OF THE INVENTION In view of the above drawbacks, it is an object of the present invention to provide an ultrasonic delay line that is further miniaturized.

Structure of the Invention In order to achieve this object, the ultrasonic delay line of the present invention includes a piezoelectric transducer having a thickness-shear vibration mode in a thin metal plate, propagates ultrasonic vibration in a direction perpendicular to the vibration, and The delayed signal is reflected by one end face of the piezoelectric transducer, and the delayed signal is received by another piezoelectric transducer, and the delayed signal is not transmitted directly from the input piezoelectric transducer to the output piezoelectric transducer. A slit is provided between the two piezoelectric transducers.

Furthermore, in order to prevent ripples from occurring due to unnecessary reflections, the end face on the reflection side that reflects the delayed signal is cut diagonally with respect to the vibration direction of the piezoelectric transducer, and A vertical slit is made, and a sound absorbing material such as silicone rubber is coated on top of the slit.

The ultrasonic delay line constructed as described above is rolled into a spiral shape and placed in a cylindrical package.

With this configuration, it is possible to obtain an ultrasonic delay line that is much smaller in shape than a conventional ultrasonic delay line that propagates through glass.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the basic configuration of an ultrasonic delay line in one embodiment of the present invention. In Fig. 1, 1 is a metal thin plate, 2 is an end surface that reflects a delayed signal,
3a is an input side piezoelectric transducer, 3b is an output side piezoelectric transducer, 4 is a lead wire, 5 is a slit inserted between the piezoelectric transducers 3a and 3b, and 6 is a slit for removing unnecessary reflected waves. , 7 is a sound absorbing material. The arrow on the right side of the figure indicates the vibration direction of the input side piezoelectric transducer 3a.

The operation of the ultrasonic delay line configured as described above will be described below.

First, when a signal enters the input side piezoelectric transducer 3a, it causes thickness shear vibration in the direction of the arrow on the right side of Fig. 1, causes ultrasonic vibration near the surface of the thin metal plate 1, and propagates in a direction perpendicular to the vibration. , metal thin plate 1
The signal is reflected at the end face 2, reaches the output side piezoelectric transducer 3b, and is converted into an electrical signal.

Since the delay time is determined by the propagation speed and propagation distance of the ultrasonic vibration, the end face 2 that reflects the delayed signal
By removing the , the propagation distance can be changed and the delay time can be finely adjusted.

In addition, since the slit 5 is inserted between the input side piezoelectric transducer 3a and the output side transducer 3b, the input and output piezoelectric transducer 3
No signal is directly transmitted between a and 3b.

Further, the end face opposite to the end face 2 that reflects the delayed signal is cut diagonally with respect to the vibration direction of the piezoelectric transducers 3a, 3b, and a slit 6 is cut perpendicularly to the vibration direction of the piezoelectric transducers 3a, 3b.
By applying the sound absorbing material 7 thereon, it is possible to eliminate the effects of ripples and the like due to unnecessary reflection from the end surface opposite to the end surface 2 that reflects the delayed signal.

A device with delay characteristics as described above,
By rolling it into a spiral shape and placing it in a cylindrical package as shown in Figure 2, it is possible to obtain an ultrasonic delay line that is smaller in shape than conventional ultrasonic delay lines that use glass as a delay medium. can.

Effects of the Invention As described above, the present invention provides two piezoelectric transducers on a thin metal plate, reflects a delayed signal output from one of the piezoelectric transducers on one end face of the thin metal plate, and A small ultrasonic delay line can be obtained by giving a delay effect by receiving it with a piezoelectric transducer, and by rolling up the thin metal plate into a spiral shape and placing it in a cylindrical package. The industrial effects are significant.

[Brief explanation of drawings]

FIG. 1 is a basic configuration diagram of an embodiment of the ultrasonic delay line of the present invention, and FIG. 2 is an external view of the ultrasonic delay line before being put into a cylindrical package. DESCRIPTION OF SYMBOLS 1... Metal thin plate, 2... End surface that reflects a delayed signal, 3a... Input side piezoelectric transducer, 3b
... Output side piezoelectric transducer, 4 ... Lead wire, 5 ... Slit, 6 ... Slit, 7 ... Sound absorbing material, 8 ... Vibration direction of input side piezoelectric transducer.

Claims (1)

[Claims] 1. Piezoelectric transducers on the input side and the output side are provided on a thin metal plate, and ultrasonic vibrations are propagated in a direction perpendicular to the vibration direction of the piezoelectric transducer on the input side, and at least one of the thin metal plates is reflected by two end faces,
An ultrasonic delay line characterized in that it is received by an output side piezoelectric transducer. 2. The ultrasonic delay line according to claim 1, characterized in that a slit is provided between the piezoelectric transducers on the input side and the output side. 3 The end face opposite to the end face that reflects the delayed signal is cut diagonally with respect to the vibration direction of the piezoelectric transducer, a slit is made in the propagation direction of the delayed signal, and a sound absorbing material is provided on top of the slit. An ultrasonic delay line as claimed in claim 1. 4. The ultrasonic delay line according to claim 1, characterized in that a thin metal plate provided with a piezoelectric transducer is rolled into a spiral shape and enclosed in a cylindrical package.