JPS59218029A - Ultrasonic wave delay line - Google Patents

Abstract

PURPOSE:To attenuate an unnecessary signal by applying a resin or the like to both ends of a converting element at a part in contact with or nearly contacted to a piezoelectric porcelain electromechanical converting element of a glass delay medium. CONSTITUTION:The piezoelectric porcelain electromechanical converting elements 16 and 17 are fitted to an input/output part of the glass delay medium 15. An adhesives 18 made of epoxy resin or glassy material is applied to both end parts of the piezoelectric porcelains at a part in just contact with the piezoelectric porcelain or nearly contacted. A signal through paths other than the primary path is attenuated by applying the adhesives 18 and only the main signal is passed. Then, unnecessary reflected signals 20, 21 are very less in comparison with the main signal 19. Thus, the adhesive attenuates and decreases the unnecessary reflected level.

Description

Detailed Description of the Invention The present invention allows the main signal A of the ultrasonic signals propagating in the glass delay medium of an ultrasonic delay line to pass through, and attenuates the signals passing through other paths to eliminate unnecessary reflections. The idea was to create a small, high-performance ultrasonic delay line for use in video cameras, television receivers, and VTRs.

A conventional ultrasonic delay line is shown in FIG. Glass delay medium 1
Piezoelectric ceramic electromechanical transducers 2 and 3 are attached to the input and output ends of the
, 6 and 6, 7 are extraction. When an electric signal is applied to the input side conversion element 2 via the lead wires 4 and 5, it is converted into an ultrasonic signal by the conversion element 2, propagates through the delay medium 1 through a path 8, and is output to the output side. The signal reaches the conversion element 3, is converted into an electric signal again, and is taken out via lead wires 6 and 7. At this time, the ultrasonic waves radiated into the glass delay medium 1 have a fixed directivity angle and a zyde rope as shown in FIG. For this reason, in addition to the original path 8, there is a signal that goes to the output end through paths 9 and 1o, and as a result, as shown in FIG. 12, Signal 1 of route 10
It has 3. These 12.13 signals that are originally unnecessary, so-called unnecessary reflected signals, are generated. These unnecessary reflected signals appear as disturbances on the screen of video equipment, so
As for the ultrasonic delay line, it is desirable that unnecessary reflected signals be as small as possible.

The present invention aims to provide an ultrasonic delay line with small unnecessary reflected signals, and one embodiment of the present invention will be described below with reference to the drawings.

FIG. 4 shows an embodiment of an ultrasonic delay line according to the present invention. Piezoelectric ceramic electromechanical transducers 16 and 17 are attached to the input and output portions of the glass delay medium 16.

Epoxy resin or glass adhesive 18 is applied to both ends of the piezoelectric ceramic at a portion of the glass delay medium 16 that is just in contact with or almost in contact with the piezoelectric ceramic.

By applying adhesive 18, 9, as shown in FIG.
The signals on the 10 paths are attenuated and only the main signal passes through. Therefore, as shown in FIG. 5, the unnecessary reflected signals 20 and 21 are extremely low compared to the main signal 19. In this way, the adhesive is effective in reducing the level of unwanted reflections.

As described above, the present invention is capable of attenuating unnecessary signals by applying a resin or the like to both ends of the piezoelectric electromechanical transducer of a glass delay medium in contact with or almost in contact with the piezoelectric electromechanical transducer. It is.

[Brief explanation of the drawing]

Figure 1 is a plan view of a conventional ultrasonic delay line, Figure 2 is a diagram showing the directivity of the radiation signal of the delay line, Figure 3 is a diagram showing the signal level of the delay line, and Figure 4 is a diagram showing the directivity of the radiation signal of the delay line. FIG. 5 is a plan view of an ultrasonic delay line in an embodiment of the present invention, and is a diagram showing the signal level of the delay line. 16...Glass delay medium, 16.17...
- Piezoelectric ceramic electromechanical transducer, 18...adhesive. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure "f0 Figure 3 Figure 4 R Figure 5

Claims (1)

[Claims] A piezoelectric ceramic electromechanical transducer is attached to each of the input and output ends of the glass delay medium, and a resin is attached to a portion of the glass delay medium that is almost in contact with the piezoelectric ceramic electromechanical transducer and at both ends of the piezoelectric ceramic electromechanical transducer. Ultrasonic delay line coated with etc.