JP2005033748A - Ultraslim piezoelectric receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultraslim piezoelectric receiver having waterproofness and easy to be assembled for generating an acoustic pressure and frequency characteristics required in the commercial scene and avoiding a useless space produced by sticking a piezo-electric oscillating element on an enclosure and the like. <P>SOLUTION: A frame body thin film is formed by engraving the surface of the enclosure, to which a piezoelectric oscillating element is stuck. The piezoelectric oscillating element is stuck to the enclosure thin film and embedded in the enclosure. Then, larger acoustic pressure is generated as compared with a conventional case, and a space with a wall thickness of the housing is sufficient, and a projected part as a useless space caused by the piezoelectric oscillation element can be avoided. Even in a method in which the piezo-electric oscillating element at an inside-space inner wall of the enclosure is held by pinching, or in a method in which the frame body itself with the embedded piezoelectric oscillating element is assembled, as one unit, in a case and the like, the same frequency characteristics and the acoustic pressure mentioned above are obtained, and a useless space in installation can be eliminated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ultra-thin piezoelectric receiver using a piezoelectric vibration element.

  In a receiver using a piezoelectric vibration element in which a conventional piezoelectric element is bonded to a metal plate or resin, the piezoelectric vibration element is bonded to an independent case or casing in order to obtain the required frequency characteristics and sound pressure. It was necessary to vibrate the whole.

In particular, when a piezoelectric vibration element is used as a receiver of a small electronic device such as a mobile phone, the piezoelectric vibration element is affixed to one surface of a protection plate or window or a casing of the mobile phone (for example, see Patent Document 1). .)
Japanese Patent Application 2000-266504

  However, recently, there is a demand for a receiver with a large sound pressure (120 dB or more) in the frequency band of 300 Hz to 3000 Hz, and the sound pressure level (about 110 dB) when a piezoelectric vibration element is attached to a housing is insufficient. Therefore, it is necessary to have a structure that can produce a larger sound pressure.

  In addition, when a piezoelectric vibration element is attached to one side of the housing, the overall thickness is the combined thickness of the housing and the piezoelectric vibration element, and that much space is required for installation in a small electronic device. . In addition, since the surface area of the piezoelectric vibration element is often smaller than the surface area of the housing, a portion of the housing surface where the piezoelectric vibration element is not attached becomes a useless space.

  The present invention has been made in view of such circumstances, can generate sound pressure and frequency characteristics that are required in the market, and is wasted by sticking the piezoelectric vibration element to a housing or the like. It is an object of the present invention to provide an ultra-thin piezoelectric receiver that requires no space and is waterproof and easy to incorporate.

  In the present invention, a thin film of a casing having a thickness of 0 mm or more and 0.7 mm or less is dug using a thin piezoelectric vibration element having a thickness of about 0.1 mm to 0.2 mm to dig into the surface of the casing to which the piezoelectric vibration element is attached. The piezoelectric vibration element is attached to the thin film part with an adhesive or a tape, or both ends of the piezoelectric vibration element are connected to the inner wall of the space by cutting in the inner wall of the space inside the housing or by providing protrusions. To provide an ultra-thin piezoelectric receiver in which the piezoelectric vibration element is embedded in the housing, or an ultra-thin structure in which the housing embedded with the piezoelectric vibration element is incorporated into a case as a unit. The above problem is solved by providing a piezoelectric receiver.

  The present invention provides an ultra-thin piezoelectric receiver having a structure in which a piezoelectric vibrating element having a thickness of about 0.1 mm to 0.2 mm is embedded and the piezoelectric vibrating element is embedded in a casing. Sound pressure (about 125 dB to 130 dB) can be realized. At the same time, since the piezoelectric vibration element is embedded in the housing, it is sufficient that there is enough space for the case, and there is no need for installation space such as the protruding part of the piezoelectric vibration element. It becomes possible.

  The ultra-thin piezoelectric receiver of the present invention has a case where the thickness of the housing thin film portion to which the piezoelectric vibration element is attached is 0 mm to 0.7 mm (excluding 0 mm) and 0 mm, or the piezoelectric vibration element is embedded. Three embodiments in which the housing itself is incorporated as a unit into another housing are assumed. Hereinafter, it will be described in order.

FIG. 1 shows an embodiment of an ultra-thin piezoelectric receiver according to the present invention, in which the piezoelectric vibrating element 6 is carried around the receiver when the housing thin film portion 2 is not less than 0 mm and not more than 0.7 mm (except in the case of 0 mm). It is sectional drawing embedded in the housing | casing 1 of electronic devices, such as a telephone.
In FIG. 1, the front and back surfaces of the casing in the vertical direction are dug in each case with the casing thin film portion 2 interposed therebetween, but there are cases in which the piezoelectric vibrator 6 is not dug out.
Moreover, the setting position of the housing thin film portion 2 is arbitrary in the housing, and can be freely set within a range in which the piezoelectric vibration element 6 does not come out on the surface.

FIG. 4 is a view showing a pasting form of a piezoelectric vibration element in a conventional piezoelectric receiver. In a conventional piezoelectric receiver, a piezoelectric vibration element is attached to a protective plate, a liquid crystal display element, or a window surface in the case of the electronic device. However, in the present invention, the case of the electronic device is directly used. by providing a space so that the piezoelectric vibrating element 6 enters 1, a method of embedding by bonding a piezoelectric vibrating element 6 in the space is employed. Since the thickness of the piezoelectric vibration element is about 0.1 mm to 0.2 mm, if the thickness of an internal part or display board used for the case, housing, or electronic device in which the element is embedded is about 1 mm to 2 mm or more, the element Can be embedded. In the conventional method, the thickness of the case where the piezoelectric vibration element is pasted is about 1 mm to 2 mm, and when the conventional piezoelectric vibration element of about 1 mm thickness is pasted there, the total thickness is about 2 mm to 3 mm. In comparison, a thinner piezoelectric receiver can be created. At the same time, it is possible to ensure waterproofness by embedding the piezoelectric vibration element 6 in a case or the like.

Further, FIG. 2 shows a graph of sound pressure and frequency characteristics obtained when the thickness of the casing thin film portion is 0.5 mm. The graph line 7 shows the sound quality characteristics obtained without changing the graph line 8. Shows a case where a sound quality characteristic is adjusted by adding a filter.
In addition, even in thicknesses other than 5 mm, the same graph can be obtained as long as the thickness is 0 mm or more and 0.7 mm or less.
In FIG. 2, the vertical axis represents the sound pressure generated and the horizontal axis represents the frequency. In general, at a frequency of 300 to 3200 Hz, if the sound pressure falls within the range of 106 ± 3 dB, it is recognized as a receiver, and the current sound pressure of an average piezoelectric receiver at 300 to 3200 Hz is about 110 dB. .
However, in recent markets, there is a demand for a large sound pressure of 120 dB or more, and the sound pressure of a conventional piezoelectric receiver cannot satisfy the demand and is insufficient.

On the other hand, in the ultra-thin piezoelectric receiver according to the present invention, the sound pressure at a frequency of 300 to 3200 Hz is 125 dB or more as shown by the graph line 7 in FIG. 2, and the sound pressure is larger than that of the conventional piezoelectric receiver. In addition to being obtained, at a frequency of 300 to 1000 Hz, it is flat at 125 dB and the sound pressure is stable.
Further, by adding a filter, it is possible to adjust a sound quality characteristic to obtain an arbitrary sound pressure and frequency characteristic as shown by the graph line 8 and to provide a receiver that is more adapted to actual requirements.

FIG. 3 shows an embodiment of the present invention in which the piezoelectric vibration element 6 is sandwiched inside the case 5, and is a view assuming a case where the housing thin film portion is 0 mm. In FIG. 3, a protrusion is provided inside the case 1, and both ends of the piezoelectric vibration element 6 are adhered to the protrusion with an adhesive or tape 5. A method may be used in which a notch having the thickness of the piezoelectric vibration element 6 is formed inside and the both ends of the piezoelectric vibration element 6 are sandwiched between the notches and held.

In this case as well, as in the embodiment of FIG. 1, the piezoelectric vibration element 6 itself can be embedded in the case or display board of the electronic device, and at the same time, the sound pressure and frequency characteristics equivalent to those in FIG. 2 can be obtained. .

Further, as one embodiment of the present invention, it is also possible to incorporate the piezoelectric vibration element 6 embedded in the case 5 as shown in FIG. It is included in the scope of the invention.
In this case as well, as in the embodiment of FIG. 1, the piezoelectric vibration element 6 itself can be embedded in the case or display board of the electronic device, and at the same time, the same sound pressure and frequency characteristics as in FIG. 2 can be obtained.
In addition, since it is a single unit, it is not only waterproof, but also can be easily incorporated into an electronic device.

  FIG. 1 is a cross-sectional view of an embodiment of the ultra-thin piezoelectric receiver of the present invention in which a piezoelectric vibration element is bonded to a housing thin film portion and embedded in the housing.   FIG. 2 is a graph showing sound pressure and frequency characteristics obtained when the thickness of the housing thin film portion is 0.5 mm in the ultra-thin piezoelectric receiver of the present invention.   FIG. 3 is a cross-sectional view of an embodiment of the ultra-thin piezoelectric receiver according to the present invention in which a piezoelectric vibration element is sandwiched in a housing and embedded in the housing.   FIG. 4 is a view showing a pasting form of a piezoelectric vibration element in a conventional piezoelectric receiver.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Case or case 2 Case thin film part 3 Piezoelectric element 4 Metal plate or resin 5 Adhesive or tape
6 Piezoelectric vibration element 7 Graph line of sound quality characteristic obtained when the thickness of the housing thin film portion is 0.5 mm 8 Graph line of sound quality characteristic obtained by adding a filter when the thickness of the housing thin film portion is 0.5 mm

Claims (4)

A piezoelectric receiver using a thin piezoelectric vibration element in which a piezoelectric element is bonded to a metal plate or resin.
By digging in the vertical direction of one side or both sides of the casing to provide a casing thin film portion with a thickness of 0 mm to 0.7 mm, and the piezoelectric vibration element is attached to the casing thin film portion with an adhesive or tape, Alternatively, an ultra-thin piezoelectric receiver characterized in that the piezoelectric vibration element is embedded in the casing by sandwiching the piezoelectric vibration element in a space inner wall provided in the casing.   The ultra-thin piezoelectric receiver according to claim 1, wherein the casing thin film portion is provided at an arbitrary position inside the casing.   The piezoelectric element is formed by a method of providing a cut in the inner wall in the horizontal direction and sandwiching both ends of the piezoelectric vibration element in the cut, or a method of providing a protrusion on the inner wall and placing both ends of the piezoelectric vibration element on the protrusion. 2. The ultra-thin piezoelectric receiver according to claim 1, wherein a vibration element is sandwiched inside the casing.   2. The piezoelectric vibration element embedded in the casing thin film portion or a piezoelectric vibration element sandwiched between space inner walls provided in the casing is incorporated into another casing as an independent device. The ultra-thin piezoelectric receiver described.

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