JPH03234149A - Portable telephone set - Google Patents

Abstract

PURPOSE:To reduce a noise signal due to surrounding noise from a transmission signal considerably by arranging 1st and 2nd microphones so that the center direction of the directivity of the 2nd microphone crosses a part parted from a rear face of a 2nd end face of a case. CONSTITUTION:A case 1 is almost shaped to be a prism and a speaker 2 is arranged to a part, of a front face 11 close to an upper face 12 while taking its lengthwise direction as the vertical direction and two microphones 3, 4 are arranged close to an angular part between the front face 11 and a lower face 13. In this case, the center direction 32 of the directivity of the microphone 4 is selected to be in crossing with a part parted from a rear face 14 of the lower face 13 and the center direction 31 of the microphone 3 is selected to be in crossing with the front face 11 in almost opposite to the direction 32. Thus, the rear face 14 of the case 1 close to the lower face 13 is not used only the microphones 3, 4 and a noise signal due to surrounding noise from in a transmission signal is considerably reduced.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a mobile phone.

[Conventional technology]

Conventionally, as shown in a side view of a first conventional example in FIG. 2, a mobile phone uses a nearly rectangular parallelepiped-shaped housing 6, and a speaker 2 is arranged at the top of the front with the longitudinal direction of the housing 6 as the vertical direction. , it was customary to place the microphone 3 at the lower front. Further, the lower part on the rear side of the housing 6, that is, behind the microphone 3, is often used as a storage space for the battery 5.

By the way, since mobile phones are often used in noisy places such as inside cars or factories, devices that use two microphones to cancel out the surrounding noise have become practical. A side view of such a second conventional example is shown in FIG.

In this second conventional example, a microphone 3 is arranged at the front lower part of the housing 7, and a microphone 4 is further arranged at the rear lower part. When microphones 3 and 4 are arranged in this way, the center direction of the directivity of microphone 3 and the direction of microphone 4 are
Since the direction is almost opposite to the direction of the center of the fingering, most of the user's voice is picked up by the microphone 3 and hardly any by the microphone 4. On the other hand, ambient noise is often picked up almost equally by microphones 3 and 4, so by using the difference signal between the output signal of microphone 3 and the output signal of microphone 4 as the transmission signal, the ambient noise can be greatly reduced. can be offset and reduced.

[Problem to be solved by the invention]

The conventional mobile phone described above that uses two microphones to cancel out ambient noise uses the lower part of the housing as the mounting location for the microphones on both the front and rear sides, so the lower part of the housing is used as the mounting location for the battery. It has the disadvantage that it cannot be used as other storage space.

SUMMARY OF THE INVENTION An object of the present invention is to provide a mobile phone that can cancel out ambient noise by using two microphones, and that can also use the lower part of the housing as a storage space for batteries and other items.

[Means to solve the problem]

In the mobile phone of the present invention, a speaker is disposed on the front surface close to a first end in the longitudinal direction of a substantially rectangular parallelepiped-shaped housing, and a first speaker is disposed on the front surface close to a second end opposite to the first end. A second microphone is arranged so that the direction of the center of directivity is almost opposite to that of the first microphone, and the output signal of the second microphone and that of the first microphone are arranged. In a mobile phone that uses a difference signal from an output signal as a transmission signal, the center direction of the directivity of the second microphone intersects with a portion of the second end surface of the casing that is remote from a rear surface. The device is configured by arranging the first and second microphones.

Further, in the mobile phone of the present invention, the battery may be housed on the rear side of the housing near the second end.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a side view of one embodiment of the present invention.

The housing 1 of this embodiment has a substantially rectangular parallelepiped shape, and the speaker 2 is arranged in a portion close to the upper surface 12 of the front surface 11 with its longitudinal direction being the vertical direction. Two microphones 3 and 4 are placed close to. With this arrangement, the center direction 32 of the directivity of the microphone 4 is arranged so that the center direction 32 of the directivity of the microphone 4 intersects with the part of the lower surface 13 that is remote from the rear surface 14;
is arranged to be substantially opposite to the direction 32 and intersect with the front surface 11. By arranging the microphones 3 and 4 in this way, the rear surface 14 side near the bottom surface 13 of the housing 1 is not occupied by the microphones 3 and 4.
This part can be used as a storage space for batteries 5 or other items.

By arranging the speaker 2 and the microphones 3 and 4 as described above, most of the user's voice is picked up by the microphone 3, and hardly any by the microphone 4.

On the other hand, since ambient noise is often picked up almost equally by microphones 3 and 4, by using the difference signal between the output signal of microphone 3 and the output signal of microphone 4 as the transmission signal, the noise caused by the ambient noise can be reduced. The signal generated by the user's voice is largely canceled out by the transmitted voice signal, and the signal generated by the user's voice is hardly canceled out by the voice signal, so the noise signal due to ambient noise in the voice signal is significantly reduced. be done.

〔Effect of the invention〕

As explained above, the present invention uses two microphones, one of which is placed at the lower front of the housing, and the center of the directivity of the other microphone is the same as the center of the directivity of the other microphone. By arranging them in almost opposite directions, and intersecting them at a portion away from the rear surface of the bottom surface of the housing, it is possible to significantly reduce noise signals caused by surrounding noise from the transmitted signal. Moreover,
This has the advantage that the lower part of the housing can be used as a storage space for batteries and other items.

[Brief explanation of drawings]

FIG. 1 is a side view of an embodiment of the present invention, FIG. 2 is a side view of a first conventional example of a mobile phone, and FIG. 3 is a side view of a second conventional example. 1... Housing, 2... Speaker, 3, 4
・・Microphone, 5・・・・Battery.

Claims (1)

[Scope of Claims] 1. A speaker is arranged on the front surface near a first end in the longitudinal direction of a substantially rectangular parallelepiped-shaped housing, and a speaker is arranged on the front surface near a second end opposite to the first end. A second microphone is arranged so that the direction of the center of directivity is almost opposite to that of the first microphone, and the output signal of the second microphone and the first microphone are arranged. In a mobile phone that uses a difference signal from an output signal as a transmission signal, the center direction of the directivity of the second microphone intersects with a portion of the second end surface of the housing that is remote from a rear surface. A mobile phone characterized in that the first and second microphones are arranged as follows. 2. The mobile phone according to claim 1, wherein a battery is housed on the rear side of the housing near the second end.