JPS5880999A - Loud speaker - Google Patents

Abstract

PURPOSE:To obtain both satisfiable output sound pressure and directivity by fitting a flat cross-shaped diaphragm provided with a voice coil to the top surface of a magnetic circuit having four L-shaped magnetic gaps. CONSTITUTION:On the top surface of a plate 12 having a cross-shaped pole piece 13 stood stop, four rectangular top plates 15 are arranged on four rectangular magnets 14. Between those plates 15 and pole piece 13, a magnetic circuit 17 having four L-shaped magnetic gaps 16 is constituted and on this circuit 17, a flat cross-shaped diaphragm 18 is arranged. On the reverse surface of the diaphragm 18, a spiral printed voice coil 19 is formed opposite to the gaps 16. Consequently, the large area of the diaphragm is secured because of the long sides of the diaphragm 18 to obtain large output sound pressure, and directivity in both lateral and longitudinal directions is improved because of the short sides.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a speaker constructed by forming a spiral printed voice coil on the lower surface of a flat diaphragm.

A conventional speaker of this type was constructed as shown in FIG.

That is, a pole piece 2 is provided vertically protruding from the center of the upper surface of a rectangular plate 1, and rectangular magnets 3 and 4 are arranged on both sides of this pole piece 2.
A rectangular upper plate 6.6 is disposed on the pole piece 2 and the upper plates 5, 6, and a magnetic circuit 9 is provided in which two parallel elongated magnetic gaps 7.8 are formed between the pole piece 2 and the upper plates 5 and 6. 9 on the upper surface and the magnetic gap 7 on the lower surface.
．． A flat diaphragm 11 made of a synthetic resin film or the like on which a spiral-shaped printed voice coil 10 corresponding to 8 is attached is attached.

In order to obtain a high output sound pressure with such a configuration, a diaphragm 11 with a wider area or a lighter diaphragm 11 is required, and in order to improve the directional characteristics of the speaker in the high frequency range, a diaphragm 11 with a wider area is required. A narrow or small diaphragm 11 is required, making it difficult to obtain one that satisfies both output sound pressure and directivity characteristics.

In other words, the larger the dimension or diameter of the diaphragm 110, the greater the attenuation in the high frequency range, and the horizontal direction is considered to be more important for the directional characteristics of a speaker. 31- “ It was made long and short rectangular in the horizontal direction.

However, the directivity characteristics of the sound pressure output in the vertical direction are largely attenuated for the reasons mentioned above, which is not desirable.

The present invention eliminates the above-mentioned conventional drawbacks, and aims to provide a speaker with improved directivity characteristics of output sound pressure in both the vertical and lateral directions.

In order to achieve the above object, the present invention has four OIL-shaped magnetic gaps on the outside of a cross-shaped pole piece as a magnetic circuit, a cross-shaped diaphragm is incorporated into this magnetic circuit, and the lower surface of this diaphragm is It is characterized by having a magnetic gap and a corresponding printed voice coil.

Embodiments of the present invention will be described below with reference to FIGS. 2 and 3.

12Fi is a plate with a cross-shaped pole piece 13 set up on the top surface, and the top surface of this grate 12 has four rectangular pole pieces.
A magnetic circuit 1 in which four magnets 14 are arranged, and four 5-shaped magnetic gaps 16 are formed between the four upper portions of the same rectangular shape and the pole piece 13 on the magnets 14.
A flat, cross-shaped diaphragm 18 made of synthetic resin such as polymeric polyimide is arranged on the magnetic circuit 17, and the lower surface of this diaphragm 18 has the four 5-shaped magnetic fields. A spiral printed voice coil 19 is formed at a position corresponding to the gap 16.

The printed voice coil 19 is formed by depositing aluminum on the diaphragm 18 and etching it into a spiral shape.

With this configuration, a large area of the diaphragm is secured by the long side a of the diaphragm 18 to obtain a large output sound pressure, and the directional characteristics in both the vertical and lateral directions are improved by using the short pieces. It is.

Since the speaker of the present invention is constructed as described above, it can be made to have excellent directional characteristics in both the vertical and horizontal directions while maintaining a high output sound pressure, and is of great industrial value. .

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a conventional speaker, FIG. 2 is an exploded perspective view showing an embodiment of the speaker of the present invention, and FIG. 3 is a bottom view of the diaphragm of the same NuPica. 12...Plate, 1a...Pole piece, 14...Magnet, 15...Top plate, 16...Magnetic gap, 17...Mark・Magnetic circuit, 18...Diaphragm, 19...Printed voice coil.

Claims (1)

[Claims] A magnet and an upper plate are assembled into a plate having a cross-shaped pole piece on the upper surface to form a magnetic circuit in which four L-shaped magnetic gaps are formed between the pole piece and the upper plate. A speaker with a flat, cross-shaped diaphragm attached to its top and bottom surfaces with spiral printed voice coils corresponding to the four magnetic gaps mentioned above.