JPH03145206A - Ultrasonic wave delay line - Google Patents

Abstract

PURPOSE:To set two kinds of delay times independently with one ultrasonic wave delay medium by using a face of the delay medium except faces with transducers adhered to them as a reflection face for an ultrasonic wave from one input transducer only. CONSTITUTION:An ultrasonic wave delay medium 11 is formed to be a heptagon in which the ratio of lateral and longitudinal sizes a, b is nearly (n+0.5)...1 ((n) is an integral number being 1,2,3...) and three sets of faces opposite to each other are in parallel with each other. Then 2H input output transducers 14,15 are provided to the center of a side 11g and 1H input output transducers 19, 20 are provided to the edge of a side 11g respectively. Furthermore, sides 11b,11e are faces for an ultrasonic wave from the 1H input transducer 14 only, that is, 2H delay time adjustment faces, and a side 11c is a face for an ultrasonic wave from the 1H input transducer 19 only, that is, a 1H delay time adjustment face. Thus, two delay times are adjusted independently without giving any effect on each other's delay characteristic.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an ultrasonic delay line used to improve the image quality of video equipment such as video tape recorders and video cameras.

Conventional technology Figure 2 shows an example of the structure of a general 1H ultrasonic delay line (1
H is one scanning time). In Figure 2, 1 is an ultrasonic delay medium such as glass, 2 is an electrode, 3 is solder or adhesive,
4 is a transducer for 1H input, 5 is a transducer for 1H output, 6 is a lead wire for applying 1H signal, 7 is 1H
Lead wire for delay signal extraction, 8 is lead wire for grounding, 9
is an unnecessary reflection absorbing material made of epoxy for absorbing unnecessary vibrations of ultrasonic waves, and is a propagation path of 1o by 1H positive normal delay amount.

The operating principle of this ultrasonic delay line is that by applying a signal voltage to the 1H signal application lead wire 6, the 1H input transducer 4 is excited and emits ultrasonic waves to the ultrasonic delay medium 1. This ultrasonic wave propagates through the internal button and surface of the ultrasonic delay medium 1 as a transverse wave, repeating reflections along the normal delay signal propagation path 10, and reaches the 1H output transducer 5 with a delay time of 1H. The transducer 6 vibrates. This vibration is converted into an electric signal and taken out from the lead wire 7 for taking out the 1H delayed signal. However, since ultrasonic waves propagate with a certain directivity angle, there are signals with a delay time that is different from the normal delay time.

In order to attenuate this signal, as is well known, an unnecessary reflection absorbing material 9 is applied to the surface of the ultrasonic delay medium 1.

Problems to be Solved by the Invention With such a conventional configuration, only one type of delay time can be obtained. However, in PML or multi-method video decks, at least 2
Since different delay times are required, at least two ultrasonic delay lines are used. Therefore, there are problems such as the area used for the ultrasonic delay line on the Song Soo printed circuit board is large9 and the wiring pattern of the printed circuit board is complicated.
Furthermore, there was a problem of increased costs.

The present invention solves these problems, and aims to provide an ultrasonic delay medium that can independently set two types of delay times using a single ultrasonic delay medium.

Means for Solving the Problems In order to solve the above problems, the present invention has two pairs of input and output transducers bonded to one ultrasonic delay medium, and at least one plane of each of them other than the transducer bonding surface. The shape of the ultrasonic delay medium is such that a desired delay time can be obtained by adjusting each reflection surface to reflect ultrasonic waves from only one of the input transducers.

Effect The ultrasonic delay medium of the present invention allows two types of delay times to be reduced to one.
Since it can be realized with a single ultrasonic delay medium, only one ultrasonic delay line is required instead of two in the current case, which reduces the area of the printed circuit board and simplifies the wiring pattern. This also makes it possible to further significantly reduce costs.

Embodiment FIG. 1 shows an example 1 used in a multi-video tape recorder, etc.
1 shows an ultrasonic delay line of an embodiment of the present invention with delay times of H and 2H; - In Figure 1, 11 is an ultrasonic delay medium such as glass, 12 is an electrode, 13 is solder or adhesive,
14 is a transducer for 2H input, 16 is a transducer for 2H output, 16 is a lead wire for applying a 2H signal, 1
7 is the lead wire for taking out the 2H delay signal, 18 is the ground wire,
19 is a transducer for 1H input, 2o is a transducer for 1H output, 21 is a lead wire for applying a 1H signal, 2
2 is the lead wire for taking out the 1H delay signal, 23 is the ground wire,
24 is a propagation path for the 2H normal delay signal, and 26 is a propagation path for the 1 medium normal delay signal. 26 is a 2H delay time adjustment surface, and 27 is a 1H delay time adjustment surface.

In the ultrasonic delay medium 11, the length ratio of the horizontal dimension a and the vertical dimension is approximately (n + 0.5):'1 (however, n is an integer of 1, 2.3, etc.). numerical value), and 3
It has a heptagonal shape with opposing planes parallel to each other.

That is, the sides 111L and 1161 sides 11 of the arsenal delay medium 11
b and 11f1 sides 110 and 11g are parallel, and side 116 has no parallel side, thereby forming a heptagon. Then, 2H person, output transducer 14°15 is placed in the center of side 11g.
The human and output transducers 19 and 20 are respectively provided at the ends of the side 11g. Also, sides 11b and 11e
becomes the reflection surface of the ultrasonic wave by only the input 14 in 2, that is, the 2H delay time adjustment surface, and the side 1'10 is 1
It is a 1H delay time adjustment surface that is a reflection surface for ultrasonic waves generated only by the medium input transducer 19.

Although an unnecessary reflection-absorbing material is required on the surface of the ultrasonic delay medium 110, it is omitted because it is not necessary for the explanation of the present invention. Furthermore, if the two electrodes 12 are electrically connected, either one of the ground wires 18 and 23 may be used. Among them, the horizontal dimension of the delay medium 11 in the embodiment of the present invention! The dimension ratio of L=vertical dimension is 2.5:1.

The operating principle is that the side that obtains the 2H delay time applies a signal voltage to the 2H signal application lead wire 16.
The 2H input transducer 14 is excited and emits ultrasonic waves to the ultrasonic delay medium '11. As shown in the propagation path 24 of the 2H positive normal delay amount, this ultrasonic wave is repeatedly reflected at the end face of the ultrasonic delay medium 11 at a reflection angle of about 46 degrees, and reaches the side 116. Then, after being reflected at this surface with a reflection angle of approximately 0 degrees, it returns along a path that is approximately the same as the original path while repeating reflections, and reaches the output transducer 16.
vibrates. This vibration is converted into an electric signal and taken out from the lead wire 17 for taking out the 2H delay time.

Here, the delay time adjustment is performed on the delay time adjustment surface 26a (side 1
1b) or 26b (side 11e). Furthermore, the method for obtaining the 1H delay time is exactly the same as the method for obtaining the 2H delay time, except that the delay time adjustment is performed on the delay time adjustment surface 27 (side 11C). And side 1
1b, 110, and 11e are each 2H.

It serves as a reflection surface for ultrasonic waves only to obtain a 1H delay time.

As mentioned above, the basic operation is the same as the conventional example, but the ultrasonic delay medium 11 has a horizontal dimension a: a vertical dimension b==(n-)-o, 5)
: 1 (n is an integer value), and by adopting a heptagonal shape in which 2,000 opposing faces of 3m are parallel, the bonding surfaces of the two sets of input/output transducers are unified to one surface, and the delay medium is At least each of the 11 chamfers is configured to reflect ultrasonic waves from only one of the input transducers, so the two delay times can be adjusted independently without affecting the delay characteristics of the other input transducer. It is something that can be adjusted.

Effects of the Invention The present invention enables P
1 video equipment such as AL system and multi-system video deck
Since only one ultrasonic delay line is required, the area used for the ultrasonic delay line on the mounted printed circuit board is reduced, and at the same time, the wiring pattern is simplified, and in addition, it is possible to significantly reduce costs.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the structure of an ultrasonic delay line according to an embodiment of the present invention, and FIG. 2 is a plan view showing the structure of a general 1H ultrasonic delay line. 11... Ultrasonic delay medium, 12... Electrode, 13... Solder or adhesive, 14...
...2H input transducer, 15...2
Transducer for H output, 16... Lead wire for applying 2H signal, 17... Lead wire for extracting 2H delayed signal, 18.23... Earth wire, 19...
...1H input transformer%20...
・Transducer for 1H output, 21...1H
Signal application lead wire, 22...1H delayed signal extraction lead wire, 24...2H normal signal propagation path, 26...1H normal signal propagation path, 2e
a, 2sb...2H delay time adjustment surface, 27...
...1H delay time adjustment surface.

Claims (1)

[Claims] The length ratio of width (length dimension): length (height dimension) is approximately (
n + 0.5): 1 (where n is an integer value), and using a heptagonal ultrasonic delay medium in which three pairs of opposing planes are parallel, two pairs are placed on one plane of this delay medium. input/output transducers are bonded together, and at least one plane of each of the delay media other than the bonded surface serves as a reflecting surface for ultrasonic waves from only one of the input transducers.