JPH0332157Y2 - - Google Patents

Description

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

<Conventional technology and its problems> In a flat-plate speaker with the basic configuration described above, when used for 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 plate speaker is installed coaxially with a flat plate speaker for other areas has also been known.

However, conventionally known flat coaxial speakers have independent magnetic circuits and vibration systems for both other ranges and high ranges.
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 circumstances, the present invention provides a full-range type semi-coaxial speaker that can exhibit excellent high-frequency characteristics by using a single flat diaphragm at a low cost. Have a purpose in mind.

In order to achieve the above object, the flat semi-coaxial speaker according to the present invention has the basic configuration of the flat plate speaker described in detail at the beginning, and extends the voice coil bobbin to a position near the back surface of the central part of the flat diaphragm. A piezoelectric element is fixed to the extended end, and the central part of the flat diaphragm is fixedly supported on the surface side of the piezoelectric element via a spacer.

<Function> According to the flat semi-coaxial speaker according to the present invention having such a characteristic configuration, the flat diaphragm which receives the vibration action through the voice coil bobbin and the drive cone generates sufficient sound pressure in the low frequency range. The central part of the flat diaphragm is vibrated by the voltage generated by the piezoelectric element, and the central part functions as a tweeter that produces sufficiently high sound pressure in a high frequency range. 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 FIG.

<Example> An example of the present invention will be described below in detail based on the drawings.

In FIGS. 1 and 2, 5 is a flat diaphragm, and a drive cone whose one end is fixed to the bobbin 1 of the voice coil (1A) inserted into the gap of the magnetic assembly 8. 2 and an edge 4 whose outer periphery is fixed to a frame 3 to form a woofer. Reference numeral 6 denotes the voice coil bobbin 1 extending to a position near the back surface of the central portion of the flat diaphragm 5.
A piezoelectric element is fixed to the extended end of the piezoelectric element 6 by adhesive means, and the center portion 5A of the flat diaphragm 5 is attached to the front side of the piezoelectric element 6 via a ring spacer 7 and a center spacer 7'. It is fixedly supported and constitutes a tweeter. Reference numeral 9 denotes a tweeter power supply cotton thread wire having a step-up transformer 10, and 11 a cotton thread wire for woofer power supply.

<Effects of the invention> As is already clear from the above detailed description, the present invention has a basic configuration of a general-purpose flat plate speaker for other ranges, and a piezoelectric circuit that does not require a magnetic circuit and polarization voltage for high range use. In particular, in this case, the piezoelectric element 6 of the piezoelectric speaker is incorporated.
By effectively utilizing the low-frequency voice coil bobbin 1 as a support for the low-frequency range, and further utilizing the central portion of the flat diaphragm 5 for other frequencies as the high-frequency vibrating body, the overall structural member The number of spacers 7 can be kept to a minimum by adding the spacer 7 to the necessary components of the speaker for other areas, and while it can be constructed at low cost in terms of both materials and assembly, it also has excellent high-frequency characteristics. We have now been able to provide a fully excellent full-range semi-coaxial flat speaker.

[Brief explanation of drawings]

1 and 2 show an embodiment of the present invention, in which FIG. 1 is a longitudinal sectional view, FIG. 2 is a half-transverse plan view, and FIG. 3 is a graph showing characteristic curves. 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 spacer.

Claims (1)

[Scope of utility model registration request] This is a flat speaker in which a 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. The center portion of the flat diaphragm 5 is extended to a position near the back surface thereof, and a piezoelectric element 6 is fixed to the extended end thereof. 1. A flat semi-coaxial speaker characterized by being fixedly supported.