JP2014155143A - Head set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the sensitivity of a differential microphone, in a head set having a differential microphone.SOLUTION: In a head set 10, an arm head 113 accommodating a differential microphone comprises: a first sound hole 116 connected to the differential microphone; and a second sound hole 117 connected to the differential microphone, the distance between the second sound hole 117 and the earphone speaker being shorter than the distance between the first hound hole 116 and the earphone speaker. If the distance between the earphone speaker and the first sound hole 116 is L (mm), the angle between the straight line extending from the first sound hole 116 to the earphone speaker and the straight line extending from the first sound hole 116 to the second sound hole 117 is θ(°), and the median of θ is θ(°), 40≤L≤120, θ=0.0035 L-0.1781 L+15.239, θ-20≤θ≤θ+20 are all satisfied.

Description

  The present invention relates to a headset including a microphone and a speaker.

  Conventionally, a headset including a microphone and a speaker is known (see, for example, Patent Document 1).

  In Patent Document 1, a pair of first and second microphones are arranged in a spherical sound field generated by a proximity sound source. For this purpose, the first microphone is set at a position approaching the proximity sound source, and the second microphone is set farther than the distance between the first microphone and the proximity sound source. .

JP 2007-300513 A

  Patent Document 1 only describes the distance between sound holes with respect to the arrangement of the sound holes of the first and second microphones. However, when a differential microphone is used, the sensitivity greatly depends on the angle between the sound hole and the adjacent sound source. Therefore, in order to maintain good sensitivity, it is necessary to consider the angle of the sound hole with respect to the proximity sound source.

  An object of the present invention is to improve sensitivity of a differential microphone in a headset including the differential microphone.

In order to achieve the above object, the present invention provides a headset including a housing, an earphone speaker, and a differential microphone, wherein the housing includes a main body portion that houses the earphone speaker, and the differential microphone. An arm head to be accommodated, and a boom arm connecting the main body and the arm head, wherein the arm head communicates with the differential microphone, communicates with the differential microphone, and the earphone speaker. Has a second sound hole that is shorter than the distance between the first sound hole and the earphone speaker, and the distance between the earphone speaker and the first sound hole is L (mm), from the first sound hole. When an angle formed by a straight line extending to the earphone speaker and a straight line extending from the first sound hole to the second sound hole is θ (°) and the median value of θ is θ ₁ (°), 40 ≦ L ≦ 120, θ ₁ = 0.0035L ² −0.1781L + 15.239, and θ ₁ −20 ≦ θ ≦ θ ₁ +20 are all satisfied.

  According to this configuration, when the speaker wears the headset, the first and second sound holes are arranged substantially along the cheek. Since the voice emitted from the speaker can be considered to diffuse along the cheek, by arranging the first and second sound holes along the cheek, along the arrival direction of the sound wave from the near sound source The first and second sound holes are arranged. As a result, the sensitivity of the differential microphone is improved.

  In the headset described above, the first and second sound holes may be formed on the same surface of the arm head, or the first and second sound holes may be formed on different surfaces of the arm head, respectively. You may be made to do. For example, the first and second sound holes may be formed on the opposing surfaces of the arm head, respectively. Thus, if the first and second sound holes are respectively formed on different surfaces of the arm head, the sound holes can be arranged at various positions, so that microphones having various shapes can be used.

  In the headset, the earphone speaker protrudes from one side surface of the main body, and the extension direction of the arm head is bent in the direction in which the earphone speaker protrudes with respect to the extension direction of the boom arm. It is good also as a form. Thereby, it is easy to arrange the first and second sound holes so as to have an appropriate θ.

  In the above headset, the first and second sound holes may be formed along the extending direction of the arm head from the viewpoint of improving aesthetics.

  In the headset, the boom arm may be extended and retracted. Thereby, the position of the differential microphone can be adjusted to a position where the voice from the speaker can be clearly picked up.

  According to the present invention, by designing θ at an appropriate angle in the headset, the first and second sound holes are arranged substantially along the cheek when the speaker wears the headset. That is, the first and second sound holes are arranged along the arrival direction of the sound wave from the close sound source. As a result, the sensitivity of the differential microphone is improved.

It is a perspective view of the headset of one embodiment of the present invention. It is a perspective view of the headset of one embodiment of the present invention. It is a perspective view of the headset of one embodiment of the present invention. It is a side view of the headset of one embodiment of the present invention. It is sectional drawing of the differential microphone of one Embodiment of this invention. It is a figure explaining optimal arrangement | positioning of the 1st and 2nd sound hole of one Embodiment of this invention. It is the measured value θ ₁ of θ with respect to L in one embodiment of the present invention. It is the graph of (theta) with respect to L of one Embodiment of this invention. It is an example of the value read from FIG. It is an enlarged view of the arm head of one Embodiment of this invention. It is an enlarged view of the arm head of one Embodiment of this invention. It is an enlarged view of the arm head of one Embodiment of this invention. It is an enlarged view of the arm head of one Embodiment of this invention. It is an enlarged view of the arm head of one Embodiment of this invention. It is an enlarged view of the arm head of one Embodiment of this invention. It is a side view of the headset which has an extendable boom arm of one embodiment of the present invention. It is a side view of the headset which has an extendable boom arm of one embodiment of the present invention.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, each embodiment can also be implemented combining in the possible range.

  1-3 is a perspective view of a headset according to an embodiment of the present invention, and FIG. 4 is a side view of the headset. 1-3, an XYZ axis in which the arrow direction indicates the positive direction is added.

  As shown in FIGS. 1 to 3, the headset 10 includes a housing 11, an ear pad 12, a multifunction button 13, an LED (Light Emitting Diode) lamp 14, a charging terminal 15, and a volume button 16. ing. This headset 10 is a type that is attached to one ear of a speaker. Note that an ear hook may be provided to prevent falling from the ear. The ear hook may be a rubber ring provided in the vicinity of the ear pad 12, for example.

  The ear pad 12 is a member protruding in a direction between the −Z direction and the + X direction from the surface on the −Z direction side of the housing 11 (speaker housing portion 114 described later), and is arranged to face the output surface of the earphone speaker. It is installed. The ear pad 12 has a hole 121 for outputting sound from the earphone speaker.

  The multifunction button 13 is an operation button formed on the side surface of the housing 11 (a control unit accommodating unit 114 described later). The multifunction button 13 is a button for selecting and executing various functions of the headset 10. The LED lamp 14 is formed beside the multi-function button 13, and indicates whether the power is on / off and being charged by the lighting, extinguishing, and color of the LED. The charging terminal 15 is formed next to the LED lamp 14 and is a terminal for connecting a cord for charging the headset 10. The volume button 16 is an operation button formed on the side of the housing 11 opposite to the multifunction button 13 and is a button for adjusting the volume output from the earphone speaker.

  The casing 11 includes a main body 111, a boom arm 112 extending in the + X direction from one end of the main body 111, and an arm head 113 formed at the tip of the boom arm 112 (one end opposite to the main body 111). And. The housing 11 is formed, for example, by combining a plurality of resin molded members.

  The main body unit 111 includes a control unit storage unit 114 that stores a control unit that controls each unit, and a speaker storage unit 115 that stores an earphone speaker. The control part accommodating part 114 is a substantially rectangular parallelepiped shape. The speaker housing portion 115 is a member protruding in the −Z direction from the inside (speaker side) of the control portion housing portion 114 and is inserted into the ear. The earphone speaker has a disk shape, and the speaker housing portion 115 can also have a disk shape that covers the earphone speaker having the shape. Note that the earphone speaker accommodating portion 115 may not protrude from the control portion accommodating portion 114. In this case, the ear pad 12 may be shaped to hold the ear pad 12 attached to the ear.

  The boom arm 112 is a member that connects the main body 111 and the arm head 113, extends in the front direction of the speaker's face, and accommodates a wiring that connects the differential microphone (bidirectional microphone) and the control unit. 1-3, the boom arm 112 linearly extends in the + X direction from the center of the end on the + X direction side of the control unit accommodating portion 114 in FIGS. The boom arm 112 may have a shape along the contour of the speaker. That is, the shape extends in the + X direction and is curved in the −Z direction.

  The arm head 113 is, for example, a substantially rectangular parallelepiped member, and the extending direction (longitudinal direction) of the arm head 113 with respect to the extending direction (+ X direction) of the boom arm 112 is the −Z direction side (of the speaker at the time of wearing). Bent to the buccal side. This is because the arm head 113 is arranged along the speaker's cheek. When the boom arm 112 is short, the arm head 113 can extend along the speaker's cheek even if the extending direction of the arm head 113 is the same + X direction as the boom arm 112.

  A differential microphone is accommodated in the arm head 113. The arm head 113 is formed with first and second sound holes 116 and 117 that are through-holes communicating with the differential microphone. When the differential microphone 20 shown in FIG. 5 described later is used, the first sound hole 116 is connected to the first microphone sound hole 27 described later, and the second sound hole 117 is connected to the second microphone sound hole 28 described later.

  As the differential microphone, a SMD (Surface Mount Device) type rectangular parallelepiped can be preferably used. For example, a differential microphone as shown in FIG. 5 can be used. FIG. 5 is a cross-sectional view of an example of a differential microphone.

  The differential microphone 20 includes a microphone housing 23 having a substantially rectangular parallelepiped shape formed by a mounting portion 21 and a lid portion 22 that covers the mounting portion 21. Inside the microphone housing 23, there are a first MEMS (Micro Electro Mechanical System) chip 24, a first ASIC (Application Specific Integrated Circuit), a second MEMS chip 25, and a second ASIC 26. Contained. The microphone casing 23 is formed with first and second microphone sound holes 27 and 28.

  The first and second MEMS chips 24 and 25 are made of silicon chips and have first and second diaphragms 241 and 251, respectively. The first diaphragm 241 reaches from above through the first microphone sound hole 27, and the second diaphragm 251 reaches from both above and below through the first and second microphone sound holes 27 and 28. . In the first and second MEMS chips 24 and 25, when the first and second diaphragms 241 and 251 vibrate due to the arrival of sound waves, the capacitance between the fixed electrodes (not shown) changes. As a result, sound waves (sound signals) incident on the first and second MEMS chips 24 and 25 can be extracted as electrical signals. That is, the first and second MEMS chips 24 and 25 have a function of converting sound signals into electrical signals.

  When sound is generated outside the differential microphone 20, sound waves input from the first microphone sound hole 27 reach the upper surface of the first diaphragm 241 through the first sound path 31, and the first diaphragm 241. Vibrates. As a result, a change in capacitance occurs in the first MEMS chip 24. The electrical signal extracted based on the change in the capacitance of the first MEMS chip 24 is an amplifier circuit of a first ASIC (not shown, but present on the back side of the drawing with respect to the first MEMS chip 24). Is amplified and output.

  When sound is generated outside the differential microphone 20, sound waves input from the first microphone sound hole 27 reach the upper surface of the second diaphragm 251 through the first sound path 31, and the second The sound wave input from the microphone sound hole 28 reaches the lower surface of the second diaphragm 251 through the second sound path 32. For this reason, the second diaphragm 251 vibrates due to the sound pressure difference between the sound pressure applied to the upper surface and the sound pressure applied to the lower surface. As a result, the capacitance of the second MEMS chip 25 changes. The electrical signal extracted based on the change in the capacitance of the second MEMS chip 25 is amplified by the amplifier circuit of the second ASIC 26 and output.

  If the distance from the sound source to the first diaphragm 241 is constant, the sound pressure applied to the first diaphragm 241 is constant regardless of the direction of the sound source. That is, when the first MEMS chip 24 side is used, the differential microphone 20 exhibits omnidirectional characteristics that uniformly receive sound waves incident from all directions.

  On the other hand, when the second MEMS chip 25 side is used, the differential microphone 20 does not exhibit omnidirectional characteristics but exhibits bidirectional characteristics. If the distance from the sound source to the second diaphragm 251 is constant, the second time when the sound source is in the direction of 0 ° or 180 ° (the direction connecting the first and second microphone sound holes 27, 28). The sound pressure applied to the diaphragm 251 is maximized. This is because the difference between the distance from which the sound wave reaches the lower surface of the second diaphragm 251 from the second sound hole 28 and the distance from the sound wave to the upper surface of the second diaphragm 251 from the first sound hole 27. This is because it becomes the largest.

  On the other hand, when the sound source is in the direction of 90 ° or 270 °, the sound pressure applied to the second diaphragm 251 becomes the minimum (0). This is because the difference between the distance from which the sound wave reaches the lower surface of the second diaphragm 251 from the second sound hole 28 and the distance from the sound wave to the upper surface of the second diaphragm 251 from the first sound hole 27. This is because it becomes almost zero. That is, when using the second MEMS chip 25 side, the differential microphone 20 is highly sensitive to sound waves incident from the directions of 0 ° and 180 °, and is incident from the directions of 90 ° and 270 °. Shows low sensitivity to acoustic waves (bidirectional).

  As described above, the differential microphone 20 collects a long-distance sound and a function as a bidirectional microphone excellent in far-field noise suppression performance (obtained by using a signal extracted from the second MEMS chip 25). It is configured to have a function as a possible omnidirectional microphone (obtained by using a signal extracted from the first MEMS chip 24).

  Further, the differential microphone may have a configuration in which the first MEMS chip 24 and the first ASIC are omitted. As such a configuration, for example, a vibration unit that converts a sound signal into an electric signal based on vibration of the diaphragm, first and second sound holes facing outside, and sound waves input from the first sound hole A differential microphone comprising a first sound path that transmits to one surface of the previous diaphragm and a second sound path that transmits sound waves input from the second sound hole to the other surface of the previous diaphragm. Can be mentioned.

  Next, the arrangement of the first and second sound holes 116 and 117 formed in the arm head 113 will be described in detail. First, the extending direction (longitudinal direction) of the arm head 113 with respect to the extending direction of the boom arm 112 is bent in the direction in which the earphone speaker protrudes (the speaker's cheek side when worn). The first and second sound holes 116 and 117 are formed along the extending direction of the arm head 113 on the same surface of the substantially rectangular parallelepiped arm head 113 (upper side surface when mounted in FIGS. 1 to 4). . By forming the first and second sound holes 116 and 117 along the extending direction of the arm head 113, an image in which the first and second sound holes 116 and 117 are arranged in an orderly manner with respect to the arm head 113 can be obtained. Giving and improving aesthetics.

  The first sound hole 116 is disposed near the tip of the arm head 113, while the second sound hole 117 is disposed near the end of the arm head 113 on the boom arm 112 side. That is, the distance between the second sound hole 117 and the earphone speaker is shorter than the distance between the first sound hole 116 and the earphone speaker. The shapes of the first and second sound holes 116 and 117 are not particularly limited, and may be an ellipse or a polygon including the circle shown in FIGS.

  As described above, the sensitivity of the differential microphone varies greatly depending on the angle between the first and second sound holes 116 and 117 and the proximity sound source (speech uttered by the speaker). Specifically, as described above, the sensitivity of the differential microphone is improved by arranging the first and second sound holes 116 and 117 along the arrival direction of the sound wave from the proximity sound source.

  FIG. 6 is a diagram for explaining the optimal arrangement of the first and second sound holes 116 and 117. Using a human head model, three states are shown in which the first and second sound holes 116 and 117 are arranged along the cheek (contour) when the headset 10 is worn. These three states are due to specifications in which the length of the boom arm 112 is different.

  Since it can be considered that the sound emitted from the speaker is diffused along the cheek, the first and second sound holes 116 and 117 are arranged along the cheek so that the arrival direction of the sound wave from the proximity sound source , The first and second sound holes 116 and 117 are arranged. As a result, the sensitivity of the differential microphone is improved.

  Therefore, it is considered to design the first and second sound holes 116 and 117 along the cheek. First, as shown in FIG. 4, the distance between the center of the earphone speaker and the center of the first sound hole 116 is L (mm), a straight line extending from the center of the first sound hole 116 to the center of the earphone speaker, and the first sound hole. An angle formed by a straight line extending from the center of 116 to the center of the second sound hole 117 is defined as θ (°).

  Then, θ is designed so that the first and second sound holes 116 and 117 are arranged along the speaker's cheek when worn. L is preferably at least 40 mm or more in order to secure a size for accommodating the earphone speaker and the differential microphone, and it is 120 mm or less so that the arm head 113 does not pass through the mouth when worn. desirable. Therefore, here 40 ≦ L ≦ 120.

  In addition, since there is a certain range in the angle at which the sensitivity of the differential microphone is improved, the first and second sound holes 116 and 117 do not need to be exactly along the speaker's cheek, and therefore θ is unique. There is no need to decide on a certain width, and a certain amount of width can be provided. Further, even if various models of human contours are considered, θ need not be uniquely determined.

As a result of these considerations, θ is ± 20 ° with the measured value θ ₁ (°) as the median when the first and second sound holes 116 and 117 are arranged along the cheek of the model head in FIG. It was found that the sensitivity of the differential microphone is improved within the range. Therefore, here, θ ₁ −20 ≦ θ ≦ θ ₁ +20.

FIG. 7 shows the results of obtaining the actual measured value θ _{1 of} θ for several Ls. Among these, the approximate expression was calculated within the range of 40 ≦ L ≦ 120. FIG. 8 shows a graph of the approximate expression, and FIG. 9 shows values read from the graph. Here, the value of θ when the second sound hole 117 is arranged on the back side (the main body 111 side) of the earphone speaker with respect to the first sound hole 116 is +, and the second sound hole 117 is the first sound hole 116. The value of θ when placed on the front side of the earphone speaker is-.

In FIG. 8, ◆ is a curve showing an approximate expression of θ ₁ . The approximate expression at this time was calculated as follows.
θ ₁ = 0.0035L ² −0.1781L + 15.239

In FIG. 8, the curve ▲ is a curve of θ ₁ +20, and the curve ■ is a curve of θ ₁ −20. Therefore, in 40 ≦ L ≦ 120, θ is a range where the range between the curve of ▲ and the curve of ■ satisfies θ ₁ −20 ≦ θ ≦ θ ₁ +20.

In summary, if the headset is designed to satisfy all of 40 ≦ L ≦ 120, θ ₁ = 0.0035L ² −0.1781L + 15.239, and θ ₁ −20 ≦ θ ≦ θ ₁ +20, the first and second The sound holes 116 and 117 are arranged substantially along the cheek. That is, the first and second sound holes 116 and 117 are arranged along the arrival direction of the sound wave from the proximity sound source. As a result, the sensitivity of the differential microphone is improved.

  Next, another embodiment will be described. 10 to 15 are enlarged views of other types of arm heads. In FIG. 10, the first and second sound holes 116 and 117 are formed on the same surface (upper side surface when mounted) of the arm head 113, and the direction in which the first and second sound holes 116 and 117 are arranged is the same as that of the arm head 113. Cross in the extending direction. According to such a form, the first and second sound holes 116 and 117 can be arranged so as to have an appropriate θ even in a specification in which the arm head 113 is not bent so much with respect to the boom arm 112.

  In FIG. 11, the first and second sound holes 116 and 117 are formed on different surfaces of the arm head 113 (an upper surface and a lower surface facing each other). In FIG. 12, the first and second sound holes 116 and 117 are formed on different surfaces of the arm head 113 (the cheek side surface and the opposing surface that is the outer surface when mounted), respectively. As described above, since the first and second sound holes 116 and 117 can be formed on different surfaces of the arm head 113, differential microphones having various shapes can be used.

  In FIG. 13, the extending direction of the boom arm 112 and the extending direction (longitudinal direction) of the arm head 113 are the same direction. The first and second sound holes 116 and 117 are formed on the same surface (upper side surface when mounted) of the arm head 113, and the direction in which the first and second sound holes 116 and 117 are arranged extends from the arm head 113. Cross in the direction. According to such a configuration, the first and second sound holes 116 and 117 can be arranged so as to have an appropriate θ even in a specification in which the arm head 113 is not bent with respect to the boom arm 112.

  14 and 15, the extending direction of the boom arm 112 and the extending direction (longitudinal direction) of the arm head 113 are the same direction. In FIG. 14, the first and second sound holes 116 and 117 are formed on different surfaces of the arm head 113 (an upper surface and an opposite surface that are the lower surfaces when mounted), respectively. In FIG. 15, the first and second sound holes 116 and 117 are respectively formed on different surfaces of the arm head 113 (a cheek side surface at the time of wearing and an opposing surface that is an outer surface). Thus, if the first and second sound holes 116 and 117 are formed on different surfaces of the arm head 113, microphones having various shapes can be used.

  16 and 17 are side views of a headset 40 having an extendable boom arm. 16 shows a state in which the boom arm 41 is extended, and FIG. 17 shows a state in which the boom arm 41 is contracted. Since the configuration other than the boom arm 41 is the same as the configuration described above, the description thereof is omitted.

  The boom arm 41 is curved to the cheek side and can be accommodated in the main body 42 at the base with the main body 42. Then, the boom arm 41 is accommodated in the main body portion 42 to achieve the state shown in FIG. The accommodating part of the boom arm 41 provided in the main body part 42 is also curved in accordance with the curvature of the boom arm 41. When the boom arm 41 is moved with respect to the accommodating part, the arm head 113 becomes the head of the speaker. Move on a curved track along the contour.

  Therefore, no matter what the state of the boom arm 41 is between FIG. 16 and FIG. 17, the curved boom arm 41 satisfies the range of θ described above. Therefore, the first and second sound holes 116 and 117 are arranged substantially along the cheek, and as a result, the sensitivity of the differential microphone is improved. Furthermore, with this configuration, the position of the differential microphone can be adjusted to a position where the voice from the speaker can be clearly picked up.

  The mechanism for extending and retracting the boom arm is not particularly limited as long as the boom arm extends and contracts along a fixed track.

DESCRIPTION OF SYMBOLS 10 Headset 11 Housing | casing 20 Differential microphone 41, 112 Boom arm 111 Main part 113 Arm head 116 1st sound hole 117 2nd sound hole

Claims (7)

In a headset with a housing, earphone speakers, and a differential microphone,
The housing includes a main body that accommodates the earphone speaker, an arm head that accommodates the differential microphone, and a boom arm that connects the main body and the arm head,
The arm head includes a first sound hole that communicates with the differential microphone, a second sound hole that communicates with the differential microphone, and a distance from the earphone speaker is shorter than a distance between the first sound hole and the earphone speaker. Have
A distance between the earphone speaker and the first sound hole is L (mm), and an angle formed by a straight line extending from the first sound hole to the earphone speaker and a straight line extending from the first sound hole to the second sound hole. If the median of θ (°) and θ is θ ₁ (°),
40 ≦ L ≦ 120
θ ₁ = 0.0035L ² −0.1781L + 15.239
θ ₁ −20 ≦ θ ≦ θ ₁ +20
A headset characterized by satisfying all of the above.   The headset according to claim 1, wherein the first and second sound holes are formed on the same surface of the arm head.   The headset according to claim 1, wherein the first and second sound holes are respectively formed on different surfaces of the arm head.   The headset according to claim 1, wherein the first and second sound holes are respectively formed on opposing surfaces of the arm head. The earphone speaker protrudes from one side of the main body,
5. The headset according to claim 1, wherein an extension direction of the arm head is bent in a direction in which the earphone speaker protrudes with respect to an extension direction of the boom arm.   The headset according to claim 5, wherein the first and second sound holes are formed along an extending direction of the arm head.   The headset according to claim 1, wherein the boom arm extends and contracts.

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