JPH1175283A - Microphone device and portable telephone set wherein same is incorporated - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the original directivity even when the microphone is stored in a narrow housing and to improve the selectivity of a transmit voice even if ambient noise is large by connecting sound ducts in the same shape to sound input parts of the front and back parts of the directional microphone symmetrically in contact. SOLUTION: The directional microphone 12 has its outer periphery supported by a coating housing 11 while being held between the right and left parts of the coating housing 11. The contact surfaces of the coating housing 11 and directional microphone 12 are brought into contact with each other and then an external sound wave or the like neither enters the coating housing 11 from the seam between the right and left parts nor leaks from the periphery of the directional microphone 12. At the right and left parts of the coating housing 11, curved sound ducts 13 and 14 which are equal in thickness and length and in symmetrical shape are formed so that the introducing directions of sound waves are bent by 90 deg.. The sound ducts 13 and 14 can introduce the states of the sound waves reaching at the front and back of the directional microphone at sound reception points into the directional microphone 12 as they are.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microphone device used for a portable telephone or a PHS used in a place with high ambient noise, and a portable telephone incorporating the microphone device. Can be selectively picked up.

[0002]

2. Description of the Related Art As shown in FIG. 3 (a), a conventional portable telephone is provided with a transmission hole 3 in a part of a housing 2, and
A microphone device is incorporated in the housing 2 where the transmission hole 3 is located.

[0003] A directional microphone is used in a portable telephone so that a call voice can be picked up without being disturbed by ambient noise. In this microphone, directivity is realized by outputting a difference or a sum of signals received at two or more adjacent points in a sound field, and the diaphragm is operated by a difference in sound pressure between two points on the front and back of the diaphragm. A device that obtains an output signal by performing such an operation is known.

FIG. 3B is a sectional view showing a state inside the housing of the portable telephone. The transmission hole 3 is provided in a portion of the housing 2 that is raised in a hemispherical shape. A ridge for positioning the directional microphone 1 stands upright inside the housing 2 corresponding to the outer peripheral position of the hemisphere, and the directional microphone 1 supports the portion excluding the sound input section on the front surface and the side surface. It is fitted and fixed to this jetty via a member 4. A lead wire 5 is connected to the back of the directional microphone 1, and the housing 2 is provided with a back transmission hole 6 through which a sound wave reaching the back of the directional microphone 1 enters.

[0005] In this conventional microphone device, the directional microphone 1 is housed in a relatively narrow air chamber portion in the telephone case, and the front direction of the directional microphone 1 is directed to the transmission hole 3 opened in the case 2. It is built to face.

A sound wave entering through the transmission hole 3 reaches only the front surface of the directional microphone 1, and the sound wave going to the back side of the directional microphone 1 passes through a gap between the jetty and the directional microphone 1. It is blocked by the supporting member 4 that closes.
Similarly, the sound wave entering from the rear transmission hole 6 reaches only the rear surface of the directional microphone 1.

In this microphone device, the ambient noise passes through the transmitting hole 3 and the rear transmitting hole 6 and the directional microphone 1
Similarly, most of the sound waves of the call voice reach the front surface of the directional microphone 1 through the transmission hole 3. Therefore, even when the surrounding noise is loud, the voice of the speaker speaking toward the transmission hole 3 is selectively converted into an electric signal by the directivity of the microphone 1.

[0008]

However, in such a configuration of the conventional microphone device, sound waves entering through the sound holes 3 and 6 formed in the housing of the portable telephone are transmitted in a narrow air chamber in the housing. Phase information for obtaining directivity is lost due to interference, so that there is a problem that good directivity characteristics cannot be obtained.

That is, when a directional microphone is accommodated in a narrow portion inside the housing of a portable telephone, the original directional characteristics cannot be obtained, and a desired transmission voice is selected with respect to ambient noise. It is extremely difficult to do.

The present invention solves such a conventional problem. Even when a directional microphone is housed in a narrow housing such as a mobile phone, the directional microphone can maintain its original directional characteristics. It is an object of the present invention to provide a microphone device having extremely good selectivity of transmitted voice even under circumstances where ambient noise is loud, and to provide a mobile phone incorporating the microphone device.

[0011]

Therefore, in the microphone device of the present invention, sound pipes of the same shape are symmetrically closely connected to the sound input sections on the front and back sides of the directional microphone.

Each of the sound conduits has substantially the same thickness and the same length, so that the sound waves introduced into the front and back portions of the directional microphone reach completely symmetrically.

Further, in a portable telephone incorporating this microphone device, even if the directional microphone is housed in a narrow telephone housing, the original directional characteristics of the directional microphone can be maintained, and even when the ambient noise is large, The transmission voice can be selected well.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS According to a first aspect of the present invention, there is provided a microphone device for picking up sound using a directional microphone, wherein each of the sound input sections on the front and back sides of the directional microphone has the same shape. The sound conduits are symmetrically connected in close contact with each other, so that the sound waves can reach the front and back portions of the directional microphone symmetrically, and the directional information obtained at the sound receiving point is obtained. Can be directly introduced into the directional microphone.

According to a second aspect of the present invention, the outer periphery of the directional microphone is supported by a covering casing, and each of the sound conduits is integrally provided in the covering casing. Can be configured.

According to a third aspect of the present invention, one end of each of the sound pipes is closely connected to the front or back of the directional microphone, and the other end of each of the sound pipes is connected to the front of the directional microphone. The microphone device is oriented in the same direction parallel to the rear surface, and when this microphone device is incorporated in a mobile phone or the like, a transmission hole opposite to the other end of each sound conduit is provided on the same surface of the telephone housing. Can be.

According to a fourth aspect of the present invention, the covering casing is divided into two parts so that it can be opened and closed right and left, and the directional microphone is sandwiched and supported between the two parts when closed. This facilitates the mounting and support of the directional microphone.

According to a fifth aspect of the present invention, the cover housing is made of a soft material such as rubber, so that external vibrations can be prevented from being transmitted to the directional microphone.

According to a sixth aspect of the present invention, a damping material for obtaining acoustic resistance is provided inside the sound conduit,
By doing so, the ambient noise can be effectively attenuated.

According to a seventh aspect of the present invention, there is provided a portable telephone having a telephone transmission hole at a lower portion of the telephone housing, and a microphone device incorporated in a position inside the telephone housing corresponding to the telephone transmission hole. As the microphone device, the microphone device according to claim 3 is incorporated so that the other ends of the sound conduits are vertically arranged, and is sent to the telephone housing so as to face the other end of each of the sound conduits. A speech hole is provided, and the directional microphone is installed so that the front direction thereof faces downward. In this way, the call voice arriving at the directional microphone from the lower transmission hole is transmitted to the directional microphone. The sound is selected and picked up according to the directivity of the sound.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The microphone device according to the embodiment of the present invention
The plan view of FIG. 1A and the cross-sectional view of FIG.
As shown in (a), a cross-sectional view taken along line x1-x2), a disc-shaped directional microphone 12 and this directional microphone 12
Housing 11 that forms sound conduits 13 and 14 for supporting sound and introducing sound waves from outside to the directional microphone 12.
And

The cover housing 11 is made of a soft material such as rubber and has a structure that can be opened and closed right and left around the hinge 17. FIGS. 1A and 1B show a state in which the left and right portions of the covered casing 11 are closed. By closing in this manner, the outer periphery of the directional microphone 12 is left and right of the covered casing 11. It is sandwiched between the portions and is supported by the cover housing 11. At this time, the contact surface between the covered casing 11 and the directional microphone 12 is in close contact with each other, and external sound waves and the like do not enter from the joint of the left and right portions of the covered casing 11 or leak from around the directional microphone 12. It has a structure.

On the left and right portions of the cover housing 11,
Sound conduit 1 curved so as to bend the direction of sound wave 90 °
3 and 14 are formed, and damping materials 22 for obtaining acoustic resistance are inserted into the entrances of the sound conduits 13 and 14, respectively. With the left and right parts of the covered casing 11 closed and the directional microphone 12 sandwiched,
One end of each of the sound conduits 13 and 14 is tightly connected to the front and back surfaces of the 12, respectively, and the other ends of the sound conduits 13 and 14 face the same direction.

The sound conduits 13 and 14 have the same thickness and length, respectively, and have symmetrical shapes. The sound conduits 13 and 14 can introduce the state of the sound wave reaching the front and back surfaces of the directional microphone at the sound receiving point into the directional microphone 12 supported by the covering housing 11 as it is. .

The lead wire 15 connected to the back of the directional microphone 12 is partially cut out from a flange 16 for completely fitting the joint of the cover 11 opened to the left and right, and is drawn out from the flange 16. .

The front direction (0 °) of the directional microphone 12 of this device is set to the right direction in FIG. This directional microphone 12 has
A close-talking microphone or a directional microphone made of an electret can be used.

FIG. 2 is a sectional view showing a state in which the microphone device is incorporated in a housing of a portable telephone or the like.

A coated housing containing the directional microphone 12
11 is a jetty-like holding device that stands on the inner surface of the telephone case 20
It is structured to be inserted and held inside 21. Insulated housing
11 is inserted into the holding device 21, the sound conduit 13
And 14 face the transmission holes 18 and 19 formed in the telephone housing 20, and the transmission holes 18 and 19 and the sound conduits 13 and 14 are connected.

The front direction of the directional microphone 12 is downward (toward the sound conduit 13). The lead wire 15 drawn out of the directional microphone 12 is drawn out through a cutout provided in the flange 16.

Next, the operation of this device will be described.

After sound waves entering from outside through the transmission holes 18 and 19 are attenuated by the damping member 22, they pass through sound conduits 13 and 14 having the same thickness and length, respectively, and pass through the front and rear surfaces of the directional microphone 12. At each sound input unit.

At this time, the sound waves arriving at the front and back of the directional microphone 12 convert the directional information obtained when the directional microphone is directly placed in the free space where the mobile phone is placed, into the same form. Introduce. That is, although the directional microphone 12 is provided in the narrow internal space of the mobile phone, the two sound conduits 13 and 14 are symmetric.
Sound wave is guided to the directional microphone 12 through the
Directivity information from outside can be introduced as it is.

For this reason, the directional microphone 12 can exhibit the original directional characteristics.

On the other hand, the speaker of the portable telephone emits a speech sound to a speech hole provided in the lower part of the casing 20 of the portable telephone, but the speech sound emitted from the mouth of the sender is ,
Usually, most of them arrive at the directional microphone 12 through the lower transmission hole 18. Therefore, only the transmitted voice is selectively picked up by the directional characteristics of the directional microphone 12 whose front direction is directed downward.

As a result, with this microphone device, a clear voice can be obtained even in a high ambient noise environment.

In this microphone device, the sound conduit 1
The braking members 22 provided on the sections 3 and 14 have an effect of effectively attenuating ambient noise having a sound pressure level lower than that of a call voice.

The shapes of the sound conduits 13 and 14 are not necessarily
The shape is not limited to the shape shown in FIG.

Further, by using a soft material such as rubber as the material of the cover housing 11, transmission of vibration from the outside to the directional microphone 12 can be prevented. Directional microphone 12
Any material can be used as long as it can be closely adhered to.

[0040]

As is clear from the above description, the microphone device of the present invention secures the original directional characteristics of the directional microphone even when the microphone device is mounted in a narrow space inside a housing as a transmitter of a portable telephone or the like. This makes it possible to clearly capture the transmitted voice even in a location where the surrounding noise is loud.

Further, since this device is extremely simple and structurally simple, the manufacturing cost is low and the mounting operation is very easy.

Further, in an apparatus having a structure in which the housing can be opened and closed by being split into two, the directional microphone can be securely mounted and supported, and the size can be easily reduced.

Also, in a device in which the entire casing is made of a soft material such as rubber, vibration from the outside is hardly transmitted to the directional microphone, and an effect of preventing vibration noise due to operation of the mobile phone can be obtained.

Also, a portable telephone incorporating this microphone device can selectively pick up only the voice of the sender and transmit clear speech even when the surroundings are noisy.

[Brief description of the drawings]

FIG. 1 is a plan view (a) and a sectional view (b) of a microphone device according to an embodiment of the present invention;

FIG. 2 is a sectional view showing a state in which the microphone device of the embodiment is incorporated in a mobile phone;

FIG. 3 is a side view (a) and a cross-sectional view (b) of a mobile phone incorporating a conventional microphone device.

[Explanation of symbols]

 1,12 directional microphone 2,20 mobile phone case 3,18,19 transmitting hole 4 support device 5,15 lead wire 6 back side transmitting hole 11 covering case 13,14 sound conduit 22 damping material

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[Procedure amendment]

[Submission date] September 8, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction contents]

According to a fifth aspect of the present invention, the covering housing is made of a soft material such as rubber, and the directional microphone is provided.
It is possible to improve the adhesiveness around the lophone and prevent external vibration from being transmitted to the directional microphone.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction contents]

According to a sixth aspect of the present invention, a damping material for obtaining acoustic resistance is provided inside the sound conduit,
By doing so, the resonance of the sound conduit itself is prevented, and
Ambient noise in a high frequency range can be effectively attenuated.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0032

[Correction method] Change

[Correction contents]

The sound waves entering from outside through the transmission holes 18 and 19 flatten the resonance characteristics with the damping material 22 and then pass through the sound conduits 13 and 14 having the same thickness and the same length, respectively. The sound reaches the front and back sound input units.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0037

[Correction method] Change

[Correction contents]

In this microphone device, the sound conduit 1
The braking material 22 provided on 3, 14 suppresses the resonance of the sound conduit itself,
Calls such as flattening the high-frequency rise of the directional microphone
It works to improve the sound quality .

Continuing from the front page (72) Inventor Masami Tachibana 4-3-1 Tsunashima Higashi, Kohoku-ku, Yokohama-shi, Kanagawa Prefecture Inside Matsushita Communication Industrial Co., Ltd.

Claims (7)

[Claims] 1. A microphone device for picking up sound using a directional microphone, wherein a sound pipe of the same shape is symmetrically tightly connected to each of the sound input sections on the front and back sides of the directional microphone. Characteristic microphone device. 2. The directional microphone according to claim 1, wherein an outer periphery of the directional microphone is supported by a covering casing, and each of the sound conduits is integrally provided in the covering casing. Microphone device. 3. One end of each of the sound conduits is tightly connected to the front or back of the directional microphone, and the other end of each of the sound conduits is parallel to the front and back of the directional microphone. The microphone device according to claim 1, wherein the microphone device faces in the same direction. 4. The cover housing is divided into two parts and can be opened and closed right and left, and the directional microphone is sandwiched and supported between the two parts when closed. 4. The microphone device according to claim 2, wherein: 5. The microphone device according to claim 2, wherein the cover housing is made of a soft material such as rubber. 6. The sound pipe according to claim 1, further comprising a damping material for obtaining acoustic resistance.
Or the microphone device according to 3. 7. A portable telephone having a transmitting hole at a lower portion of a telephone housing and a microphone device incorporated in an internal position of the telephone housing corresponding to the transmitting hole. Item 3. The microphone device according to Item 3, wherein the other end of each of the sound conduits is incorporated vertically, and the telephone housing includes a transmission hole facing the other end of each of the sound conduits; A mobile phone, wherein the directional microphone is installed with its front side facing downward.