JPH0515599U - Panel speaker - Google Patents

Abstract

(57) [Summary] [Purpose] A panel speaker that aims to improve playback sound quality by abundant and good reproduction of high frequencies. [Structure] A structure in which a piezoelectric film is attached to a diaphragm panel and a voltage is applied to the piezoelectric film to drive it.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a type of panel speaker having a flat diaphragm.

[0002]

[Prior Art]

 As shown in FIG. 3, a conventional panel speaker of this type has a diaphragm unit (12) in which (a) a thick foamed polystyrene plate (11) is used as a diaphragm and the tip of a voice coil bobbin (13) is fixed. ) Is attached, (b) a vibrating unit (22) for driving is attached to a thick wall or a flat plate (21) of glass, and the like.

[0003]

[Problems to be solved by the device]

 Therefore, in this type of conventional panel speaker, the flat plates of the vibrating plates (11) and (21) are less likely to cause a low-pitched sound reproduction region that causes piston vibration, but a high-pitched sound reproduction region that generates large divided vibrations. However, there was a problem that vibration interference occurred and the sound pressure level in the high frequency range decreased, resulting in a lack of high frequency range. Therefore, there is also a problem that high-quality high-pitched sound reproduction cannot be obtained.

In order to solve the problems of the conventional panel speaker, the present invention attaches a piezoelectric film to the diaphragm panels (11) and (21), and The purpose of this method is to improve the reproduction sound quality as a speaker by abundant and good reproduction in the high frequency range by driving by applying a voltage to the speaker.

[0005]

[Means for Solving the Problems]

 The structure of the present invention for achieving the above object will be described with reference to FIGS. 1 and 2 corresponding to the embodiment. The present invention has electrode plates on the front and back surfaces of the diaphragm panel (1). It is a panel speaker made by attaching a piezoelectric film (4) that can be applied and applying high frequency electric input.

[0006]

[Action]

 Since the present invention has such a configuration, it may be used by inputting a voice electric input as in a conventional speaker.

Therefore, in the panel speaker of the present invention, the piezoelectric film (4) attached to the surface of the diaphragm panel (1) receives high-pitched sound electrical input to generate high-pitched sound, and the high-pitched sound of the panel (1). It is possible to supplement the lack of range. As a result, it is possible to radiate the high-pitched sound and the low-pitched sound while maintaining the balance, and it is possible to perform flat sound reproduction with a small difference in height, thereby improving the sound quality.

[0008]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 are views showing an embodiment of the present invention, and FIG. 1 showing a longitudinal sectional view thereof will be explained.

(1) is a diaphragm panel made of plywood, cardboard, etc., and a driver unit (2) is attached to the back surface thereof. Then, a piezoelectric film (4) having electrode plates on both front and back sides is attached to the surface through a foam (5), and the high frequency electric output of the amplifier (3) is boosted when necessary. It is a special panel speaker that can be applied through (10) and through a high pass filter (9). The low range output of the amplifier (3) can be input to the driver unit (2) through the low pass filter (8).

When a voltage is applied to the electrode plate, the piezoelectric film (4), which is a sheet-shaped piezoelectric body, has electrode layers formed on both sides of the piezoelectric body, and the vibration that expands and contracts in the surface direction with respect to the applied voltage. Causes a sound. Since the properties of the piezoelectric body are different when the piezoelectric body is a polymeric piezoelectric material and when it is made of a ceramic body, the vibration mode is also different.Therefore, the attachment structure on the surface of the vibration plate panel (1) is different. .. That is, in the case of the polymeric piezoelectric substance shown in FIG. 1, the piezoelectric film (4) is curved by compressing the foam (5) between the piezoelectric film (4) and the panel (1). Secure the peripheral part to the panel (1). When a signal voltage is applied to the piezoelectric film (4), the piezoelectric film (4) expands and contracts in the surface direction, and is converted into vibration displacement in the normal direction of the surface by the pressure of the foam (5).

When the piezoelectric film (4) is a thin ceramic plate, as shown in FIG. 2, a constraining layer also serving as an electrode plate on one side (a non-stretchable synthetic resin plate having electrode plates attached to both sides, or a metal plate) Etc.) (6) is adhered, and the viscoelastic material sheet (7) is sandwiched and adhered to the panel (1). In this case, the ceramic thin plate (4) operates as a unimorph type piezoelectric element.

Although the embodiments considered to be typical of the present invention have been described above, the present invention is not necessarily limited to only the structures of these embodiments, and has the above-mentioned constitutional requirements referred to in the present invention, and The present invention can be carried out with appropriate modifications within the scope of achieving the object of the present invention and having the following effects.

[0013]

[Effect of the device]

 As is clear from the above description, in the panel speaker of the present invention, the piezoelectric film (4) attached to the surface of the diaphragm panel (1) produces high frequencies regardless of the vibration mode of the panel (1). As it occurs, the lack of high range in the panel (1) can be supplemented and satisfied, so that the reproduction of both high range and low range can be radiated in a balanced manner, and flat sound reproduction with little difference in pitch is possible. Therefore, it is possible to expect a remarkable practical effect that the sound quality can be improved.

Further, in the panel speaker of the present invention, since the high-frequency vibration generating portion can radiate from the entire piezoelectric film (4), it is expected that the directional characteristic in the high frequency range can be improved. It was possible to do it.

[Brief description of drawings]

FIG. 1 is a partially cutaway vertical sectional view showing an embodiment of the present invention and a drive circuit.

FIG. 2 is a partially cutaway vertical sectional view showing another embodiment of the present invention.

FIG. 3 is a vertical sectional view of a conventional example.

[Explanation of symbols] (1) Vibration plate panel (2) Drive unit (3) Amplifier (4) Piezoelectric film (5) Foam (6) Restraint layer (7) Viscoelastic sheet (8) Low pass filter (9) High pass Filter (10) Step-up transformer

Claims (1)

[Scope of utility model registration request] 1. A panel speaker in which a piezoelectric film (4) having electrode plates on both front and back surfaces is attached to the surface of a diaphragm panel (1) so that a high-range electric input can be applied.