JPH0621750A - Ultrasonic wave glass delay line - Google Patents

Abstract

PURPOSE:To provide the ultrasonic wave glass delay line with a small size at a low cost by decreasing the height of an ultrasonic wave delay medium having two delay time ultrasonic wave propagation paths. CONSTITUTION:A hexagonal ultrasonic wave delay medium 11 in which the ratio of a length of a longer side to a length of a shorter side is almost 3:1, two sets of planes faced across from each other are provided, two oblique planes whose tilt angle is 45 deg. are provided on corners faced across from each other and the two oblique planes are in parallel are used for an ultrasonic wave glass delay line applied to a video equipment such as a video tape recorder, and two pairs of input output transducers 14a, 14b and 15a, 15b are adhered on one oblique plane of the ultrasonic wave delay medium 11. Thus, the height is decreased and the material for the ultrasonic wave delay medium 11 is decreased and the processing man-hour is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic glass delay line (including a comb filter) used for improving image quality of video equipment such as video tape recorders and television receivers.

[0002]

2. Description of the Related Art In recent years, the video equipment market such as video tape recorders corresponds to various broadcasting systems in the world.
With the progress of multi-functionalization that can support both AL and NTSC systems, the miniaturization of parts in line with miniaturization and multi-functionality is progressing, and the ultrasonic glass delay line used in accordance with this Even so, there is a strong demand for downsizing, especially downsizing in height.

A conventional ultrasonic glass delay line will be described below with reference to the drawings. As disclosed in Japanese Patent Laid-Open No. 3-145206, an ultrasonic wave delay line corresponding to the conventional multi-purpose has two independent ultrasonic wave propagation paths for 1H and 2H and a delay time. The configuration was as shown in FIG. 2 (here, 1H means 1 scanning time and 2H means 2 scanning time).

In FIG. 2, 1 is an ultrasonic wave delay medium made of glass, 2 is an electrode provided on the ultrasonic wave delay medium 1, 3 is an adhesive, and 4a and 4b are 1H input and output transducers. Reference numerals 5a and 5b are 2H input and output transducers, 6 is an unnecessary reflection absorber, 7 is a 1H ultrasonic wave propagation path, and 8 is a 2H ultrasonic wave propagation path. Further, the shape of the ultrasonic delay medium 1 is formed into a heptagon with a horizontal: vertical length dimension ratio of 2.5: 1, and has two sets of planes facing each other vertically and horizontally, and two planes of these. A pair of parallel slanting planes formed at an inclination angle of 45 degrees with respect to the adhering surface of the transducers 4a, 4b, 5a, 5b adhered to one of the slanting planes is 9
There is one sloping plane formed at an angle of 0 degrees.

Next, the operation of the ultrasonic glass delay line configured as shown in FIG. 2 will be described. When a signal voltage is applied to the 1H input transducer 4a, the transducer 4a is excited and radiates ultrasonic waves to the ultrasonic delay medium 1. This ultrasonic wave propagates while repeating reflection inside the ultrasonic delay medium 1 as a transverse wave along the propagation path 7 a total of five times, and reaches the 1H output transducer 4b with a delay time of 1H. The transducer 4b vibrates due to the ultrasonic waves that have arrived, and this vibration is converted into an electric signal to obtain a 1H delayed electric signal.

Similarly, a 2H input transducer 5a
When a signal voltage is applied to the transducer 5, the transducer 5a is excited and the ultrasonic wave is radiated to the ultrasonic wave delay medium 1. This ultrasonic wave propagates while repeating a total of 11 reflections along the propagation path 8 and reaches the 2H output transducer 5b with a delay time of 2H. The transducer 5b vibrates due to the ultrasonic waves that have arrived, and this vibration is converted into an electric signal to obtain a 2H delayed electric signal.

Therefore, since the ultrasonic wave propagates with a certain directivity angle, there is a signal having a delay time different from the regular delay time, and in order to attenuate this signal, the surface of the ultrasonic delay medium 1 is attenuated. It was constructed by applying the unnecessary reflection absorbing material 6 to the.

[0008]

However, in such a conventional configuration, for example, the sound velocity of the ultrasonic delay medium 1 is 2
In the case of 540 m / s, the ultrasonic delay medium 1 has a lateral dimension =
62.5 mm, vertical dimension = 25.0 mm is required, and the vertical dimension is particularly large, which is a height that has been prominent in the recent miniaturization and height reduction of other components in high-density mounting such as VCRs. However, there was a problem in terms of high-density mounting.

The present invention solves such a problem and has a small vertical dimension and one ultrasonic delay medium.
It is an object of the present invention to provide an ultrasonic glass delay line capable of obtaining delay times of H and 2H.

[0010]

In order to solve this problem, in the ultrasonic glass delay line of the present invention, the shape of the ultrasonic delay medium is such that the dimensional ratio of the length on the long side to the length on the short side is substantially the same. 3: 1
Of the hexagonal shape and has two parallel planes facing each other, and diagonal planes each having a tilt angle of 45 degrees are provided at the opposite corners, and the two diagonal planes are made parallel to each other. And two pairs of input / output transducers are fixed to one of the two inclined planes.

[0011]

With this structure, for example, when the sound velocity of the ultrasonic delay medium is 2540 m / s, the ultrasonic delay medium having a lateral dimension of 67.5 mm and a longitudinal dimension of 22.5 mm can be used. Compared to the configuration, the vertical (height) dimension is about 2.5
It can be lowered by mm.

Further, the material of the ultrasonic delay medium can be reduced by about 3%, and the effective use of the material can be realized. In addition, the shape of the ultrasonic delay medium can be changed from the conventional heptagon to the hexagon, and the number of steps in the step of shaping the ultrasonic delay medium (generally a grinding step) can be reduced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing the structure of an ultrasonic glass delay line in one embodiment of the present invention. In FIG. 1, 11 is an ultrasonic delay medium made of glass having a thickness of about 0.7 to 1.0 mm, 12 is an electrode provided on the ultrasonic delay medium 11, 13 is an adhesive, and 14a and 14b.
Is a 1H input and output transducer, 15a
Reference numerals 15b and 15b are 2H input and output transducers, 16 is an unnecessary reflection absorber, 17 is a 1H ultrasonic wave propagation path, and 18 is a 2H ultrasonic wave propagation path.

The shape of the ultrasonic delay medium 11 has a lateral (length dimension a): vertical (height dimension b) length dimension ratio of 3:
1 hexagonal shape, two sets of planes facing each other are parallel, and sloping planes having an angle of 45 degrees are provided at the corners facing each other, and the two sloping planes are parallel to each other. Is formed in. Also, two pairs of input / output transducers 14a, 14b, 15 are provided on one of the two inclined planes.
a and 15b are adhered with an epoxy resin adhesive 13 or the like. In addition, the input / output transducers 14a, 14
b, 15a and 15b are each two piezoelectric elements or 1
The piezoelectric element is formed by providing a groove at approximately the center of the piezoelectric element or dividing the electrode of one piezoelectric element into two.

Next, the operation of the ultrasonic glass delay line of the present invention shown in FIG. 1 will be described. When a signal voltage is applied to the 1H input transducer 14a, the transducer 14a
a is excited and radiates ultrasonic waves to the ultrasonic delay medium 11. This ultrasonic wave propagates as transverse waves inside the ultrasonic wave delay medium 11 along the propagation path 17 while repeating a total of five reflections, and reaches the 1H output transducer 14b with a delay time of 1H. The transducer 14b vibrates due to the ultrasonic waves that have arrived, and this vibration is converted into an electric signal to obtain a 1H delayed electric signal.

Similarly, the transducer 15 for 2H input is used.
When a signal voltage is applied to a, the transducer 15a is excited and radiates ultrasonic waves to the ultrasonic delay medium 11. This ultrasonic wave propagates along the propagation path 18 while repeating a total of 13 reflections, and reaches the 2H output transducer 15b with a delay time of 2H. The transducer 15b vibrates due to the ultrasonic waves that have arrived, and this vibration is converted into an electric signal to obtain a 2H delayed electric signal.

The ultrasonic delay medium 11 is appropriately housed in a case having an external terminal, and the external terminal and each transducer and the electrode 12 provided on the ultrasonic delay medium 11 are connected to a lead wire or a conductive rubber. Alternatively, it is electrically connected by contact with a metal terminal.

Further, although the ultrasonic glass delay line has been described in the above-mentioned embodiment of the present invention, the same effect can be obtained by applying the present invention to a comb filter.

[0019]

The ultrasonic glass delay line of the present invention constructed as described above can have its vertical (height) dimension reduced by about 2.5 mm as compared with the conventional construction. Further, the material of the ultrasonic wave delay medium can be reduced by about 3%, and the man-hours required for processing the ultrasonic wave delay medium can be realized. As a result, the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a plan view showing the configuration of an ultrasonic glass delay line according to an embodiment of the present invention.

FIG. 2 is a plan view showing the configuration of a conventional ultrasonic glass delay line.

[Explanation of symbols]

 11 Ultrasonic Delay Medium 12 Electrode 13 Adhesive 14a 1H Input Transducer 14b 1H Output Transducer 15a 2H Input Transducer 15b 2H Output Transducer 16 Unwanted Reflective Absorber 17 1H Propagation Path 18 2H Propagation Path

Claims (1)

[Claims] 1. A dimensional ratio of a length on a long side to a length on a short side is approximately 3: 1 and has two parallel planes facing each other, and the corners facing each other have a flat surface. A hexagonal ultrasonic delay medium is provided in which oblique planes each having an inclination angle of 45 degrees are provided and the two oblique planes are parallel to each other, and 2 is provided in one of the oblique planes of the ultrasonic delay medium. An ultrasonic glass delay line made by fixing a pair of input / output transducers.