JPS6345108Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a microphone device, and more particularly to a microphone device that is incorporated inside a helmet and used in combination with a speaker.

There is a transmitting/receiving device for a driver or passenger of a motorcycle, etc., which consists of a combination of a microphone and a speaker built into a helmet. In this type of device, the microphone and speaker can only be installed at positions facing the helmet wearer's mouth and ears, respectively.
The mounting positions of both must be close to each other. By arranging the microphone and the speaker close to each other in this way, a sound feedback loop is formed between the two, which tends to cause an oscillation phenomenon (howling).

The present invention has been made in view of the above points, and an object of the present invention is to provide a microphone device that does not cause howling even when placed close to a speaker.

The microphone device according to the present invention includes a sound guide section that opens into an external space in order to guide sound pressure to a microphone housed in a predetermined housing. It is formed to increase.

Embodiments of the present invention will be described in detail below with reference to the drawings.

In FIGS. 1 to 3, reference numeral 1 denotes a helmet body made of a hard plastic material, and a cushioning material 2 made of a sponge material having a certain thickness is adhered to the inner circumferential wall of this body 1. Reference numeral 3 denotes a speaker built into the helmet main body 1, and is provided near a position facing the ears of the helmet wearer. Reference numeral 4 denotes a microphone built into the helmet main body 1 so as to constitute a transmitting/receiving device in combination with the speaker 3. The microphone 4 is housed in the housing 5 and is placed in the cushioning material 2 near the position facing the helmet wearer's mouth. Buried.

The microphone 4 is housed in the housing 1 so that its sound collecting surface 4a is substantially perpendicular to the front surface of the housing 1. The housing 5 includes a sound guiding part 6 that opens into the external space (helmet interior space) to guide sound pressure to the sound collecting surface 4a of the microphone 4, and a sound guide section 6 that opens into the external space (helmet interior space) and a surface opposite to the sound collecting surface 4a of the microphone 4 that opens into the external space. A communication portion 7 communicating with is formed. By housing the microphone 4 in the housing 1 so that the sound collection surface 4a and the back surface communicate with the outside space, the microphone 4 is housed in the housing 1 in such a way that the back surface of the microphone is completely glued to the inside of the helmet. This has the effect of suppressing howling.

In the present invention, the opposing portion 6a of the sound guiding portion 6 that faces the microphone sound collecting surface 4a is also formed to be curved. In other words, the sound guide section 6 has a shape in which the cross-sectional area of the opening increases as the distance from the microphone sound collecting surface 4a increases.

In this configuration, the sound waves generated by the helmet wearer's phone calls will be incident approximately perpendicularly to the front surface of the housing, as shown in FIG. This sound wave is reflected by the curved opposing portion 6a of the sound guiding portion 6 and is successfully incident on the microphone sound collecting surface 4a. Furthermore, the cross-sectional area of the opening of the sound guiding portion 6 increases as the distance from the sound collecting surface 4a increases, so that the sound collecting surface 4a
The sound pressure at the opening will be higher than that at the opening. Therefore, the signal level of the microphone output based on the sound waves caused by a telephone call is significantly increased compared to, for example, a structure in which the facing portion 6a of the sound guiding portion 6 is made substantially parallel to the microphone sound collecting surface 4a. On the other hand, as shown by the dashed line in FIG. 1, the sound pressure from the speaker 3 that reaches the microphone 4 along the inner wall of the helmet is approximately equal to can be considered equal. Therefore, by lowering the gain of the signal system in order to electrically suppress the increased signal level by the increased amount as described above, the signal level corresponding to the sound pressure from the speaker 3 is reduced by the same level as the increased amount. This means that the sound pressure from the speaker 3 can be substantially reduced. As a result, speaker 3 and microphone 4
This results in an effect equivalent to that of installing an obstacle in the feedback loop of the feedback loop, that is, an effect of preventing howling.

As described in detail above, according to the present invention, the sound guide part is provided with an opening to the external space to guide sound pressure to the microphone housed in a predetermined housing, and the cross-sectional area of the opening of the sound guide part is Since it is formed so that it increases as it moves away from the sound surface, howling will not occur even if the speaker and microphone are placed close to each other, which is particularly effective when these devices are installed inside a helmet.

Note that the present invention is not limited to helmets, and the same effect can be obtained even if it is applied to, for example, an intercom for simultaneous calls.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a helmet equipped with a microphone device according to the present invention, and FIG. 2 is a front view showing an embodiment of the microphone device according to the present invention.
FIG. 3 is a sectional view taken along the line A--A in FIG. 2. Explanation of symbols of main parts, 1...Helmet body, 3...Speaker, 4...Microphone, 5...
...Housing, 6...Sound guide section.

Claims (1)

[Scope of utility model registration request] The sound guide includes a microphone housed in a predetermined housing, and a sound guide part that communicates the microphone with an external space, and the sound guide part has an opening cross-sectional area that increases as the distance from the sound collection surface of the microphone increases. A microphone device characterized in that: