JPS62135007A - Ultrasonic wave delay line - Google Patents

Abstract

PURPOSE:To decrease an undesired signal and insertion loss and to improve the frequency characteristic by adhering two piezoelectric vibrators having a width a half of the thickness of an ultrasonic wave delay medium in parallel at one position of the ultrasonic wave delay medium in the broadwise direction of the said ultrasonic wave medium. CONSTITUTION:Two input/output piezoelectric vibrators 9, 10 having a width a half of the thickness of the ultrasonic wave delay medium 1 are adhered to one position of the ultrasonic wave delay medium 1 in parallel in the broadwise direction of the ultrasonic wave delay medium 1 to constitute an input/ output transducer. Through the constitution above, the length of the piezoelectric vibrator is prolonged twice more than that of a conventional piezoelectric vibrator. Further, the level of suppressing an undesired signal and insertion loss is improved and also the frequency characteristic is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates primarily to an ultrasonic delay line used for color and brightness signal processing in video equipment such as video decks and video cameras.

2. Description of the Related Art Conventionally, this type of ultrasonic delay line has had a configuration as shown in FIG. In Fig. 2, 1 is an ultrasonic delay medium such as glass, 2 is an electrode, 3 is an input piezoelectric vibrator, 4 is an output piezoelectric vibrator, 5 is a signal application 7 is a grounding lead wire, and 8 is an ultrasonic wave This is an unnecessary signal absorbing material for removing unnecessary signals.

The principle of operation of the ultrasonic delay line is that by applying a signal voltage to the signal application lead wire 6, the input piezoelectric vibrator 3 is excited. This vibration propagates inside and on the surface of the ultrasonic delay medium 1 as a transverse wave (SH wave), and reaches the output piezoelectric sensor 4 with a certain delay time, causing it to vibrate. This is converted into a voltage and taken out from the lead wire 6 for taking out the delayed signal. Since the ultrasonic delay line of this structure uses Rayleigh waves, the ultrasonic wave spreads and generates an unnecessary signal having a different delay time. In order to suppress this unnecessary signal, an unnecessary signal absorbing material 8 is applied to the surface of the ultrasonic delay medium 1.

Now, as video decks, video cameras, etc. become smaller and lighter, ultrasonic delay lines are becoming smaller and thinner. This means that the ultrasonic delay medium 1 is small.

This not only means making it thinner, but also means making the input/output piezoelectric vibrator 3°4 smaller. The downsizing of the piezoelectric vibrator, the increase in unnecessary signals, the increase in insertion loss, and the deterioration of frequency characteristics are factors.

Problems to be Solved by the Invention In such a conventional configuration, as the piezoelectric vibrator is made smaller Q, there are problems such as an increase in unnecessary signals, an increase in insertion loss, and a deterioration in frequency characteristics.

The present invention solves these problems, and although it is a small ultrasonic delay medium, it does not generate unnecessary signals.

The purpose of this invention is to provide an ultrasonic delay line with low insertion loss and excellent frequency characteristics.

Means for Solving the Problem In order to solve this problem, the present invention provides a piezoelectric vibrator having a width of 1/2 in the thickness direction of the ultrasonic delay medium at one location. Two ultrasonic delay media are laminated in parallel in the thickness direction.

Function: With this configuration, it is possible to obtain twice the length of the conventional piezoelectric sensor, and with the same ultrasonic delay medium, unnecessary signals and insertion loss are small, and ultrasonic delay with excellent frequency characteristics is achieved. This means that the lines can be realized.

Embodiment FIGS. 1a and 1b are structural diagrams showing an ultrasonic delay line according to an embodiment of the present invention. 1A is a front view, and FIG. 1B is a side view, and the same parts as in FIG. 2 are given the same numbers. 1st
In Figures a and b, a piezoelectric sensor 9 for input and output having a width of 1/2 in the thickness direction of the ultrasonic delay medium 1,
Two sheets of the ultrasonic wave delay medium 10 are pasted in parallel in the thickness direction of the ultrasonic wave delay medium 1 at one place to form an input/output transducer. By configuring this structure, it is possible to make the length of the piezoelectric vibrator twice as long as the length of a conventional piezoelectric vibrator.

Effects of the Invention As described above, according to the present invention, the level of unnecessary signals and insertion loss can be improved, and an ultrasonic delay line with excellent frequency characteristics can be easily realized.

[Brief explanation of drawings]

FIG. 1a is a front view showing an ultrasonic delay line according to an embodiment of the present invention, FIG. 1 is a side view of the same, and FIG. 2 is a front view showing a conventional ultrasonic delay line. 1... Ultrasonic delay medium, 2... Electrode,
5...Lead wire for signal application, 6...Lead wire for taking out delayed signal, 7...Lead wire for grounding,
8... Unnecessary signal absorbing material, 9... Piezoelectric vibrator for input, 1o... Piezoelectric sensor for output. Name of agent: Patent attorney Toshio Nakao and one other name
2 figure

Claims (1)

[Claims] Two piezoelectric vibrators having a width of 1/2 in the thickness direction of the ultrasonic delay medium are pasted in parallel in the thickness direction of the ultrasonic delay medium at one place, and then inserted. An ultrasonic delay line characterized by being used as an output transducer.