JP2576454B2 - Screen combined speaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to a screen in which a piezoelectric sounding body is attached to a diaphragm made of a foamed resin plate, and a screen sheet is provided on the front surface of the diaphragm. It relates to a dual-purpose speaker.

(Prior Art) As an application example of a piezoelectric speaker, there is a piezoelectric speaker in which a screen sheet on which an image is projected is attached to the front surface of the speaker, thereby adding a function as a screen and increasing the added value. FIG. 3 is a cross-sectional view showing this type of screen / loudspeaker. The screen-shared speaker has a diaphragm 3 formed by sticking two foamed resin plates 4 and 5 in the front-rear direction.
A plurality of piezoelectric sounding bodies 2 (two in the illustrated example) buried in the diaphragm 3, a foam sheet 7 having a smooth surface property attached to the front surface corresponding to the upper and lower sides of the diaphragm 3 in the drawing, and And a screen sheet 6 attached to the front surface of the camera. A resin sheet 1 is attached to the rear surface of the diaphragm 3 corresponding to the upper side in the drawing. FIG. 4 is a front view showing this type of screen / loudspeaker, particularly showing the mounting position of the piezoelectric sounding body 2. FIG. The same type of piezoelectric sounding bodies 2 are mounted symmetrically.

(Problems to be Solved by the Invention) By the way, the above-mentioned conventional screen / speaker has the following disadvantages when performing stereo reproduction. That is, in the case of a normal piezoelectric speaker, two piezoelectric speakers are installed on the left and right to perform stereo reproduction, but in the case of a screen speaker, an image is projected on a screen sheet 6 attached to the front surface of the diaphragm 3. Therefore, the diaphragm 3 cannot be divided. For this reason, the left and right integrated diaphragms 3 must be used, and the conventional screen / loudspeaker using the left and right integrated diaphragms 3 has poor separation due to interference of left and right vibrations, and is excellent. There is a problem that stereo feeling cannot be obtained.

The present invention has been made in view of such circumstances,
It is an object of the present invention to provide a screen dual-purpose speaker capable of significantly improving a stereo effect.

(Means for Solving the Problems) The present invention provides a method in which a pair of foamed resin plates forming a diaphragm are provided.
A plurality of piezoelectric sounding bodies are disposed, and a screen sheet is provided on the front surface of the diaphragm. In the speaker for screen, the plurality of piezoelectric sounding bodies have at least two types of piezoelectric sounds for low and high sounds. Composed of the body,
The piezoelectric sounding body for bass is arranged on the left and right of the center of the diaphragm, and the piezoelectric sounding body for treble is arranged on both outer sides of the piezoelectric sounding body for bass.

(Operation) According to the above configuration, it is possible to increase the separation in the high-frequency range, which is a range in which the directivity is sensitive in human hearing.

(Example) Hereinafter, an example of the present invention will be specifically described with reference to the drawings. FIG. 1 is a sectional view of a screen / speaker according to the present invention.

A diaphragm 3 that emits sound from the front side when vibration is applied
Is formed by sticking two foamed resin plates 4 and 5 made of styrene foam, foamed polyethylene or the like in the front-rear direction. Both the foamed resin plates 4 and 5 have a rectangular shape, but the foamed resin plate 4 on the front side has a step formed on the peripheral edge of its front surface.

FIG. 2 is a front view showing a mounting position of the piezoelectric sounding body 2. The plurality of piezoelectric sounding bodies 2 are composed of, for example, three kinds of piezoelectric sounding bodies 2 for low sound, medium sound, and high sound, and are attached to predetermined positions on the opposing surfaces of the foamed resin plates 4 and 5, respectively. That is, the low-frequency piezoelectric sounding body 2 is located on the left and right of the center of the diaphragm 3, the medium-tone piezoelectric sounding body 2 is on both sides of the high-frequency piezoelectric sounding body 2, and the high-frequency piezoelectric sounding body 2 is the medium sound In the vicinity of the left and right peripheral portions of the diaphragm 3, that is, outside the piezoelectric sounding body 2 for use, they are arranged in two symmetrical vertical columns.

According to this configuration, since the piezoelectric sounding body 2 for bass is attached to the central portion of the diaphragm 3, it can easily vibrate and can have a large amplitude. Also, since human hearing has poor directivity in the low frequency range, there is no need for stereo separation, and there is no problem even if it is arranged in the center.

Since the piezoelectric sounding body 2 for middle and high pitches does not require a relatively large amplitude, there is no problem even if the piezoelectric sounding body 2 is mounted near the periphery of the diaphragm 3
By being arranged near the peripheral portion, the left and right separation can be increased.

In the present embodiment, the plurality of piezoelectric sounding bodies 2 are composed of three kinds of piezoelectric sounding bodies 2 for treble, middle, and bass, but the present invention is not limited to this. For example, a structure composed of two kinds of piezoelectric sounding bodies 2 for high sound and low sound is also possible. However, in this case, the overall frequency characteristics are not flat compared to the present embodiment.

Since the mounting structure of these piezoelectric sounding bodies 2 is the same, one of them will be described below with reference to the sectional view of FIG.
Annular grooves 4a and 5a are provided in the opposing surfaces of the foamed resin plates 4 and 5 in abutting manner, and the piezoelectric sounding body 2 is held between these grooves 4a and 5a. More specifically, the piezoelectric sounding body 2 is mounted between the protrusions 4b and 5b remaining at the central portions of the grooves 4a and 5a using an adhesive or the like. For this reason, the height of the projections 4b, 5b is slightly shorter than the height of the grooves 4a, 5a.

Each piezoelectric sounding body 2 has a circular piezoelectric body 2b, 2b (for example, PZT) having a smaller diameter on both front and rear surfaces of a circular metal plate 2a.
) Are concentrically adhered to each other, and when an electric signal is supplied from an amplifier (not shown), the piezoelectric sounding body 2 drives the diaphragm 3, and the diaphragm 3 emits sound from the front side. It has become. The piezoelectric sounding body is for low tone, medium tone,
The diameter is different for treble, and the diameter is larger in the order of bass, middle, and treble.

The number of piezoelectric sounding bodies is not limited to the number shown in the illustrated example, but may be any number that can drive a diaphragm having an area that can be used as a screen.

A screen sheet 6 is attached to the front surface of the diaphragm 3, and a speaker is also functioned as a screen by projecting an image on the screen sheet 6. The screen sheet 6 has a structure in which an aluminum foil is laminated on the back surface of a transparent resin sheet whose surface is finely roughened. Further, a foam sheet 7 having a smooth surface property is attached between the screen sheet 6 and the diaphragm 3.

The specific attachment of the screen sheet 6 and the foam sheet 7 is performed as follows. That is, the foam sheet 7 is adhered to the entire front surface of the vibration plate 3 (excluding the step formed on the peripheral edge of the front surface of the foam resin plate 4) using an adhesive or the like. Thereafter, the screen sheet 6 is similarly adhered to the entire front surface of the foam sheet 7 using an adhesive or the like.

The resin sheet 1 is attached to the rear surface of the diaphragm 3 using an adhesive. In addition, a frame 8 that covers the periphery of the diaphragm 3 is provided. The frame 8 has a frame shape, and a peripheral portion of the diaphragm 3 is inserted and connected to a U-shaped groove formed over the entire length of the inner peripheral surface. In addition, an elongated tape-shaped elastic support piece 9 is interposed at the step formed on the peripheral edge of the front surface of the foamed resin plate 4 over the entire circumference.
It is a structure supported by.

(Effects of the Invention) As described above, according to the present invention, since the left and right integrated diaphragms are used without dividing the diaphragm of the screen portion, a clear image can be obtained and the piezoelectric sounding body can be mounted. By setting the position as described above, it is possible to increase the left and right separation of the high-frequency piezoelectric sounding body whose directivity is sensitive to human hearing, and obtain a good stereo feeling.

In addition, by using several kinds of piezoelectric sounding bodies divided according to the band, a flat portion of each frequency characteristic can be selected, and a flat frequency characteristic can be obtained as a whole.

[Brief description of the drawings]

1 and 2 show an embodiment of a screen / speaker according to the present invention. FIG. 1 is a sectional view and FIG. 2 is a front view. 3 and 4 show a conventional example, FIG. 3 is a sectional view, and FIG. 4 is a front view. 1 ... resin sheet, 2 ... piezoelectric sound generator, 3 ... vibration plate, 4,5 ... foam resin plate, 4a, 5a ... groove, 4b, 5b ... projection 6 ... screen sheet, 7 ... Foam sheet, 8… frame, 9… elastic support piece

Claims (2)

(57) [Claims] 1. A method according to claim 1, further comprising the step of:
A plurality of piezoelectric sounding members are disposed, and a screen / sheet speaker provided with a screen sheet on the front surface of the diaphragm. The plurality of piezoelectric sounding members include at least two types of piezoelectric sounds for bass and treble. A speaker for a screen, wherein the piezoelectric speaker for bass is arranged on the left and right sides of the center of the diaphragm, and the piezoelectric speaker for treble is arranged on both outer sides of the piezoelectric speaker for bass. . 2. The screen / loudspeaker according to claim 1, wherein said piezoelectric sounding bodies for low-pitched sound and high-pitched sound are arranged in symmetric vertical two rows.