JPS62197A - Dynamic microphone unit - Google Patents

Abstract

PURPOSE:To set the volume of an internal air chamber and to change performance on acoustic characteristic by making an adapter mobile. CONSTITUTION:An adapter 12 can be moved back and forth by the screw part 5c of a case 5a and the screw part 12a of the adapter 12 by rotating the adapter 12 engaged with the screw part 5c of the case 5a and thereby the volume of an internal air chamber 11a can be changed. Acoustic characteristic when the volume of the internal air chamber 11a is made small is shown by a curve 13 and that when the volume of the internal air chamber 11a is made large is shown by a curve 14. Thus, the acoustic characteristic can be changed easily, and lowering of cost can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a dynamic microphone unit mainly used for vocals and speeches.

Prior Art FIG. 3 shows the configuration of a conventional dynamic microphone unit. In Fig. 3, a magnet 1a% is attached to a synthetic resin case 2, a diaphragm 3, and a diaphragm 3, which partially molds a magnetic circuit section 1 consisting of a magnetic yoke 1b and a pole piece 1c. Voice coil 4, case 5,
A phase shift circuit acoustic filter 6, a rear acoustic filter 7, a rear case 8, an internal air chamber 9 formed by the synthetic resin case 2 and case 5 in which a part of the magnetic circuit part 1 is molded, and the case 5 and the rear case 8. It was composed of a rear air chamber 10 formed.

Problems to be Solved by the Invention However, in the above-mentioned dynamic microphone unit, the basic performance in terms of acoustic characteristics is determined by the internal air chamber volume, and when trying to change the performance in terms of acoustic characteristics, magnetic It is necessary to change the internal air chamber volume by changing the shape of the synthetic resin case in which part of the circuit is molded and/or the case, which has the drawback of low versatility in terms of acoustic characteristics and high cost. Ta. It is an object of the present invention to eliminate such drawbacks and provide a dynamic microphone unit with highly variable acoustic characteristics at a low cost.

Means for Solving the Problems In order to achieve the above object, the present invention provides a movable adapter on one side of the case, and by moving this adapter, the volume of the internal air chamber can be arbitrarily varied. It is something.

Effect Therefore, according to the present invention, by moving the adapter, the volume of the internal air chamber can be arbitrarily set.
This has the effect of being able to change performance in terms of acoustic characteristics.

Embodiment FIG. 1 shows the configuration of one embodiment of the present invention, and FIG. 2 is an acoustic characteristic diagram in one embodiment of the present invention. In Fig. 1, 1a is a magnet, 1b is a magnetic yoke, 1c is a pole piece, 1 is a magnetic circuit section consisting of a magnet 1a1, a magnetic yoke lb, and a pole piece 1c, and 2 is a synthetic resin case in which a part of the magnetic circuit section 1 is molded. Its upper surface is recessed so that the magnetic yoke 1b can be fitted therein, and a fitting column 2a of the magnet 1a% magnetic yoke 1b and the pole piece 1c is provided in the center thereof. 3 is a diaphragm, 4 is a voice coil mounted on the diaphragm 3, and 5a is a case having an opening 5b, and a threaded portion 5C is provided around the opening 5b. 6 is a phase shift circuit acoustic filter, 7 is a rear acoustic filter, 8 is a rear case, and 12 is an adapter, the outer periphery of which is provided with a threaded portion 12a that meshes with a threaded portion 5c provided on the case 5a. ing. 10 is a rear air chamber, 11a is a synthetic resin case in which a part of the magnetic circuit section 1 is molded, and is an internal air chamber formed by the case 5 and the adapter 12.

In this case, by rotating the adapter 12 meshed with the threaded part 5c of the case 5a, the threaded part 5c of the case 5a is removed.
The adapter 12 can be moved back and forth by the screw portion 12a of the adapter 12, and the volume of the internal air chamber 11a can be changed. Referring to the acoustic characteristic diagram in FIG. 2, the acoustic characteristic when the volume of the internal air chamber 11a is reduced is 1.
3. The acoustic characteristic when the volume of the internal air chamber 11a is increased is 14, and the acoustic characteristic can be easily varied, and cost reduction can be realized.

Effects of the Invention As is clear from the above embodiments, the present invention is provided with an adapter having a movable part for the purpose of arbitrarily varying the volume of the internal air chamber and increasing the versatility of performance in terms of acoustic characteristics. This makes it possible to create a dynamic microphone unit with high variability in acoustic characteristics at low cost without the need to create a new synthetic resin case or mold for the case in which part of the magnetic circuit is molded. have an effect.

[Brief explanation of drawings]

Fig. 1 is a side sectional view of a dynamic microphone unit according to an embodiment of the present invention, Fig. 2 is an acoustic characteristic diagram of the embodiment of Fig. 1, and Fig. 3 is a side sectional view of a conventional dynamic microphone unit. It is a diagram. 1...Magnetic circuit section, 2...Synthetic resin case, 5a...Case, 5b...Opening, 5c...Screw part , lla... Internal air chamber, 12... Adapter, 12a...
Threaded part.

Claims (1)

[Claims] A dynamic microphone unit in which a movable adapter is provided on one side of a case in which a magnetic circuit part is fixed and an internal air chamber is formed, and the volume of the internal air chamber can be arbitrarily varied by moving the adapter.