JPH0332158Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The invention is used as a speaker for various audio equipment. Specifically, one end of the drive cone is fixed to a low-frequency voice coil bobbin, and the other end of the drive cone is fixed to the outer periphery of the frame. The present invention relates to a flat semi-coaxial speaker whose basic structure is a flat speaker in which a low frequency flat diaphragm is supported by fixed edges.

[Conventional technology and its problems] In the case of a flat speaker with the above basic configuration, in the case of a full range, the output sound pressure frequency characteristics are particularly poor in high-frequency characteristics, even when compared to a cone speaker with the same diameter. not enough. (The thin solid line in Figure 3 is the characteristic of a flat speaker with a diameter of 16 cm, and the chain line is the characteristic of a cone speaker with a diameter of 16 cm.) In addition, in order to improve such high frequency characteristics,
For example, as disclosed in Japanese Utility Model Application Publication No. 59-52795, a flat coaxial speaker in which a high frequency flat speaker is coaxially installed with a low frequency flat speaker is also known.

However, conventionally known flat plate coaxial speakers have independent magnetic circuits and vibration systems for both low and high frequencies.
It has the drawback that it requires a large number of components and requires a lot of labor to assemble, making the overall product very expensive.

[Means for Solving the Problems] In view of the above-mentioned circumstances, the present invention also provides a planar speaker of this type in which the upper end of the voice coil bobbin protrudes upward through the center of the flat diaphragm. Focusing on the fact that there has been a dust cap attached to the protruding end,
The purpose of this invention is to provide a full-range type speaker with excellent high-frequency characteristics, which is a simple improvement over the conventional product.

In order to achieve this object, the flat semi-coaxial speaker according to the present invention has the flat plate speaker described in detail at the beginning as its basic structure, and the voice coil bobbin is passed through a hole formed in the center of the flat diaphragm. The voice coil bobbin is fixedly supported by the flat diaphragm at the peripheral edge of the hole, and a piezoelectric element is fixed to the protruding end of the voice coil bobbin, and the surface of the piezoelectric element is fixed to the protruding end of the voice coil bobbin. It is characterized by the structure in which a high-frequency vibrating body is supported on the side.

[Function] When using the flat semi-coaxial speaker according to the present invention having the characteristic configuration as described above, the vibration of the voice coil bobbin is transmitted to the flat diaphragm via the bobbin and the drive cone, The plate generates sufficient sound pressure mainly in the low frequency range and acts as a woofer, while the vibrating body that vibrates due to the voltage generated by the piezoelectric element acts as a tweeter that generates a sufficiently high sound pressure in high frequencies. As a whole, the speaker functions as a full-range type speaker with excellent high-frequency characteristics, as shown by the thick solid line in Figure 3.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

1 and 2, reference numeral 5 denotes a flat diaphragm for low frequency (woofer), one end of which is connected to the bobbin 1 of the voice coil 1A inserted into the gap of the magnet assembly 8. It is supported by the other end of the fixed drive cone 2 and an edge 4 whose outer periphery is fixed to the frame 3, and in the center thereof, a vibrating body 7 for high frequency (tweeter), which will be described later, is installed coaxially. A hole 5A is formed through the hole 5A. The upper end portion of the voice coil bobbin 1 extends through the hole 5A and projects above the flat diaphragm 5.
The voice coil bobbin 1 is fixedly supported on the flat diaphragm 5 by adhesive means at the peripheral edge thereof. Reference numeral 6 denotes a piezoelectric element fixed to the protruding end of the voice coil bobbin 1 by adhesive means in place of a dust cap, and on the surface side of the piezoelectric element 6, there is a flat plate-shaped vibrating body 7 for high frequency. The vibrating body is fixedly supported. 9 is a tweeter power supply cotton thread wire having a step-up transformer 10;
is a cotton thread wire for woofer power supply.

Note that the tweeter vibrating body 7 is not limited to a flat plate-shaped vibrating body, and a cone-shaped vibrating body may also be used.

[Effects of the invention] As is clear from the detailed description above, the invention uses a general-purpose flat speaker as its basic configuration, incorporates a piezoelectric speaker that does not require a magnetic circuit and a polarizing voltage, and produces a coaxial system. In this case, the piezoelectric element 6, which is a component of the piezoelectric speaker, is used to construct a composite speaker.
The extended portion of the voice coil bobbin 1 of the low-frequency flat speaker is effectively used as a support for the vibrating body 7, and the extended portion of the voice coil bobbin 1 not only functions as a mere support but also serves as a support for the flat plate speaker. The central portion of the diaphragm 5 is fixedly supported to improve the low frequency characteristics of the flat diaphragm 5. Therefore, the number of component parts is kept to the minimum necessary,
In addition, as mentioned above, the entire structure can be constructed at low cost by a simple improvement such as fixing the piezoelectric element 6 to the protruding end of the bobbin 1 instead of the dust cap of this type of speaker that has conventionally existed. We have now been able to provide a full-range semi-coaxial speaker that exhibits excellent reproduction characteristics over the entire range from low to high frequencies.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention,
Figure 1 is a longitudinal sectional view, Figure 2 is a half-transverse plan view, and Figure 3 is a longitudinal sectional view.
The figure is a graph showing a characteristic curve. 1 is a voice coil bobbin, 2 is a drive cone, 3 is a frame, 4 is an edge, 5 is a flat diaphragm, 6 is a piezoelectric element, and 7 is a high frequency vibrating body.

Claims (1)

[Claims for Utility Model Registration] A low-frequency flat diaphragm 5 is supported by the other end of a drive cone 2 whose one end is fixed to a low-frequency voice coil bobbin 1 and an edge 4 whose outer periphery is fixed to a frame 3. It is a flat speaker,
The voice coil bobbin 1 is made to pass through a hole 5A formed in the center of the flat diaphragm 5 and protrude above the flat diaphragm 5, and the voice coil bobbin 1 is inserted into the flat plate at the peripheral edge of the hole 5A. A piezoelectric element 6 is fixed to the protruding end of the voice coil bobbin 1, and a high-frequency vibrating body 7 is supported on the surface side of the piezoelectric element 6. Flat semi-coaxial speaker. A flat semi-coaxial speaker according to claim 1, wherein the high-frequency vibrating body 7 is a flat vibrating body.