JPS5838706Y2 - Diaphragm of electrodynamic electroacoustic transducer - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a diaphragm in an electrodynamic electroacoustic transducer such as a headphone or a microphone.

The diaphragm of an electrodynamic electroacoustic transducer such as a headphone or a microphone is made into a circular shape using an extremely thin plastic film, and the diaphragm is attached to a case or a yoke by pasting its outer periphery to a case or a yoke.

To explain this with reference to the drawings, first of all, in Fig. 1, 1 is a diaphragm.

This diaphragm 1 is made of a plastic film having a thickness of, for example, about 25 to 50 microns, and has a large number of ribs 1C tangential to the center portion 1a extending from the center portion 1a to the outer peripheral portion 1b. It is something that exists.

The diaphragm 1 has a voice coil 2 on the lower surface of its central portion 1a.
is attached (see Figure 2).

When the diaphragm 1 is attached to a case or a yoke, the voice coil 2 is positioned within an annular gap formed by the outer periphery of a magnet and a ring-shaped yoke, which will be described later.

In FIG. 2, 3 is a case molded from synthetic resin, and 4 is a metal yoke.

These case 3 and yoke 4 have a U-shaped cross section, and a ring-shaped yoke 5 is attached to the opening thereof.

A magnet 6 is attached to the center of these.

In this structure, the outer peripheral part 1b of the diaphragm 1 is placed on the upper surface of the side part 3a formed on the inner peripheral part of the case 3, and after being positioned, a solvent or diluted adhesive is applied to the outer peripheral part 1b. It is dripped, spread around the entire circumference by capillary action, and joined by melting the side portion 3a of the case 3.

In the case of FIG. 3 in which the shape of the yoke is changed, a stepped portion is formed on the ring-shaped yoke 5, and the outer circumferential portion 1b of the diaphragm 1 is placed on the outer portion 5a of the stepped portion and joined. In this case, the outer portion 5a of the yoke 5 is coated with a diluted adhesive in advance, and after this adhesive dries, it is possible to bond with a solvent or diluted adhesive in the same way as in Fig. 2. Become.

In any of these cases, if the outer peripheral portion 1b of the diaphragm 1 does not have a flat surface, a bonding defect will occur.

Particularly recently, in order to improve the performance of headphones and microphones, the thickness of the diaphragm 1 has tended to become thinner (for example, about 12 to 20 microns). - There is a problem that the surface is not maintained and it tends to look like waves.

This is thought to be due to the influence of temperature variations during the manufacturing of the diaphragm 1, but in any case, if the outer peripheral portion 1b does not have a flat surface, the adhesion and bonding will be incomplete and the desired performance will not be maintained. I can't do that.

The present invention was made to solve this problem.

An embodiment of the present invention will be described with reference to FIG. 4. In this case, a concentric rib 1d and a radial rib 1f are provided on the outer peripheral portion 1b of the diaphragm 1, which is the adhesive surface.

In this way, the flat surface is maintained by the reinforcing effect of the ribs 1d and 1f, and the capillary effect of the space between the ribs 1d and If improves the flow of the solvent and diluted adhesive to the case or yoke. This results in a complete bonding of the two.

As mentioned above, this invention has concentric and radial ribs on the outer adhesive surface of the diaphragm, so even if the diaphragm is made of thin material (plastic film), the case or Adhesion and bonding to the yoke are performed reliably, and stable quality can be maintained.

[Brief explanation of drawings]

Fig. 1 is a plan view of a conventional diaphragm, Fig. 2 is a sectional view showing the case where the diaphragm is attached to the case, Fig. 3 is a sectional view showing the case where the diaphragm is attached to the yoke, and Fig. 4 is a sectional view showing the case where the diaphragm is attached to the yoke. The figure is a plan view showing an embodiment of the present invention. 1... diaphragm, 1b... outer periphery, ld
, If...Rib, 2...Voice coil, 3...Case, 4,5...Yoke.

Claims (1)

[Scope of utility model registration request] In a diaphragm of an electrodynamic electroacoustic transducer whose outer periphery is attached to a case or yoke and vibrates with respect to the case or yoke, concentric and radial ribs are provided on the outer periphery adhesive surface of the diaphragm. A diaphragm for an electrodynamic electroacoustic transducer characterized by: