JP2001211496A - Flat speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flat speaker with a small depth. SOLUTION: This speaker consists of a permanent magnet which is of a disk shape having a circular space at the center and whose annular inner edge and annular outer edge are magnetic poles different from each other and a diaphragm which is of a flat shape whose outer diameter is larger than that of the flat part of the disk-shaped permanent magnet, where an electrical insulated wire is provided curledly in an area corresponding to the shape of the flat part of the disk permanent magnet over the whole surface and which is also fixed with an adhesive material including soft magnetic material powder. The diaphragm is arranged in parallel over the flat part of the disk permanent magnet with an interval provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat speaker.

[0002]

2. Description of the Related Art The vibrating portion of a speaker is usually cone-shaped, and the larger the diameter, the greater the depth. Accordingly, large-volume, high-quality audio equipment and audiovisual equipment are inevitably large-sized with a large frontage and depth.

[0003] On the other hand, from the needs of consumers, it is required to reduce the thickness of audio equipment and audiovisual equipment in order to increase the indoor space. The use of liquid crystals for video is becoming thinner, but the practical use of thinner speakers is behind.

[0004]

SUMMARY OF THE INVENTION The present invention provides a flat speaker having a small depth.

[0005]

SUMMARY OF THE INVENTION A flat speaker according to the present invention is a permanent magnet having a disk shape having a circular space in the center and having an annular inner edge portion and an annular outer edge portion having mutually different magnetic poles, and the disk. Soft magnetic material powder having an outer diameter larger than the outer diameter of the flat portion of the disk-shaped permanent magnet, on one surface of which an electrically insulated wire is spirally disposed in a range corresponding to the shape of the flat portion of the disk-shaped permanent magnet. Characterized in that the diaphragm is fixed in parallel with a gap above the flat surface of the disk-shaped permanent magnet.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a sectional view showing a basic structure of a flat speaker according to the present invention, FIG. 2 is a plan view of a disk-shaped permanent magnet portion, and FIG. 3 is a plan view of a diaphragm portion. The disk-shaped permanent magnet 1 has a disk shape having a circular space 2 in the center, and its annular inner edge and annular outer edge are mutually different magnetic poles. 1 and 2, the annular inner edge is S
Although the case where the pole and the annular outer edge portion are the N pole is shown, the reverse is also possible. The diaphragm 3 is a flat plate having an outer diameter larger than the outer diameter of the flat portion of the disk-shaped permanent magnet 1, generally paper, and on one surface thereof, the electrically insulated wire 4 is formed in a range corresponding to the shape of the flat portion of the disk-shaped permanent magnet. It is arranged in a spiral and is fixed by an adhesive material 5 containing a soft magnetic material powder. The vibrating plate 3 is arranged above the flat surface of the disk-shaped permanent magnet 1 at intervals and in parallel. Reference numeral 6 denotes a casing,
Reference numeral 7 denotes a soft iron yoke. As the permanent magnet to be used, one having (BH) max = 30MGOe or more is desirable.

The operation mechanism will be described. The magnetic flux generated by the permanent magnet 1 having a disk shape having a circular space in the center and having an annular inner edge portion and an annular outer edge portion having mutually different magnetic poles is generated by an adhesive material 5 containing a soft magnetic powder on the diaphragm 3.
Focused inside. A magnetic field generated by flowing a sound current through the spirally arranged electrically insulated wire 4 generates a repulsive force or an attractive force with a disk-shaped permanent magnet located below, and as a result, the diaphragm 3 vibrates. To reproduce the sound.

[0008]

According to the present invention, since the diaphragm is flat, the depth of the speaker is reduced, and the thickness of the audio equipment and the audiovisual equipment can be easily reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a basic structure of a flat speaker according to the present invention.

FIG. 2 is a plan view of a disk-shaped permanent magnet portion.

FIG. 3 is a plan view of a diaphragm portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Disc-shaped permanent magnet 2 Circular space 3 Vibration plate 4 Electric insulating wire 5 Adhesive material containing soft magnetic powder 6 Casing 7 Yoke

Claims (1)

[Claims] 1. A permanent magnet having a circular space in the center and having an annular inner edge and an annular outer edge having mutually different magnetic poles, and an outer diameter larger than the outer diameter of a plane portion of the disk-shaped permanent magnet. From a diaphragm having a flat plate with a diameter and an electrically insulated wire on one surface thereof spirally arranged in a range corresponding to the shape of the flat portion of the disk-shaped permanent magnet and fixed with an adhesive material containing a soft magnetic material powder A flat speaker, wherein the diaphragms are arranged in parallel above the flat surface of the disk-shaped permanent magnet at intervals.