The present application claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2017-044745, filed on Mar. 9, 2017. The above application(s) is hereby expressly incorporated by reference, in its entirety, into the present application.
The present invention relates to a voice recorder for recording voices.
A voice recorder for recording voices input through a microphone is known (refer to patent document 1). In addition to the microphone, the voice recorder also has, for example, an IC memory in which voice data can be recorded and a speaker, and is capable of reproducing the voice data. Such voice recorders are also called IC recorders, and the like. Many voice recorders have a right-and-left pair of microphones to be capable of recording in stereo.
Some voice recorders having a right-and-left pair of microphones are equipped with two barrel type microphones on one side of a box-like body section, for example. Among these voice recorders, such a type of products are conventionally known that are capable of changing the microphones between an outward position in which a sound-collection axis perpendicular to a diaphragm of one microphone does not intersect a sound-collection axis of the other, and an inward position in which the sound-collection axes intersect each other (refer to patent documents 1 to 3 and non-patent document 1). In general, the outward position is called A-B configuration, and the inward position is called X-Y configuration. There are a variety of configurations for changing the position of each microphone.
Patent Document 1: JPA No. 2007-043510
Patent Document 2: JPA No. 2009-171249
Patent Document 3: JPA No. 2010-021667 (corresponding to US 2010/0008511 A1)
Non-Patent Document 1: Zoom Company Limited, Handy Video Recorder Q4n User's Guide, p. 3 to p. 5 (2015 ZOOM CORPORATION)
In the inward position (X-Y configuration), setting the microphones to intersect each other in different heights from each other is preferable to spacing the microphones from each other in the right to left direction, because phase difference between the right and left microphones is reduced when the microphones intersect each other, as described in non-patent document 1.
However, in the prior art in non-patent document 1, the change between the outward position (A-B configuration) and the inward position (X-Y configuration) requires a sliding operation to make the heights of the microphones different, in addition to a turning operation to turn each microphone by 180 degrees to bring the microphones to the intersected position. In addition to the intricate operation, this prior art requires two mechanisms to turn and to slide the microphones, and thus involves a problem of complicating the structure.
The object of the present invention is to provide a voice recorder with a right-and-left pair of microphones, which can change over between an inward position (X-Y configuration) with little phase difference and an outward position (A-B configuration), without any intricate operation or complicated structure.
For the above mentioned object, a voice recorder of the present invention is provided with a body section, a pair of right and left microphones, and a couple of holders. The microphones are provided on the body section, each microphone having a diaphragm to collect voices, and each sound-collecting axis perpendicular to the diaphragm extends in an axial direction of the microphone. The couple of holders are placed side by side in the body section in such a manner that the holders are capable of turning on individual rotation axes which are parallel to each other, and the holders hold the microphones with the sound-collecting axes tilted to the rotation axes, respectively. By turning each microphone 180 degrees from an inward position in which the sound-collecting axes of the microphones intersect each other, the microphones are changed to an outward position in which the sound-collecting axes of the microphones do not intersect. Each microphone is placed offset from the individual rotation axis on each holder in such a direction that, in the inward position, the sound-collecting axes are spaced apart from each other in a vertical direction parallel to a vertical plane which is perpendicular to both of the parallel rotation axes.
It is preferable that each sound-collecting axis is parallel to a horizontal plane perpendicular to the vertical plane in the inward position and in the outward position.
It is preferable to stagger the holders in such a manner that the respective rotation axes are spaced apart from each other in the vertical direction.
It is preferable that each microphone has the same offset which is a distance from the rotation axis of each holder to the sound-collecting axis of one microphone held on the one holder, in the vertical plane.
Assuming that PV represents a distance between the rotation axes of the holders in the vertical direction, the distance PV is determined by formula (1) below, and the offset distance OF S of each microphone is preferably equal to a half of the distance PV, that is, PV/2.
PV=(D/2+D/2+C)/2 formula (1)
Wherein, D is a diameter of each microphone and C is a clearance between the microphones.
When the distance between the rotation axes of the holders in the horizontal plane is assumed as PH, the distance PH is determined by formula (2) below, on the basis of an intersection point at which the two sound-collecting axes of the microphones intersect.
PH=2L·cos(90°−θ/2) formula (2)
Wherein, L is a length of each sound-collecting axis from the intersection point to the rotation axis of each holder, and θ is an angle between the two intersecting sound-collecting axes.
It is preferable that the diaphragms of the microphones intersect each other in the inward position. More preferably, the diagrams of the microphones intersect at the center of each diaphragm in the inward position.
It is preferable to provide an interlocking mechanism which interlocks the holders to cause one holder to turn as the other holder is turned.
It is preferable that the interlocking mechanism includes a joint member which transmits a turning force of one holder to the other holder as a turning force therefor. The joint member is connected on opposite ends thereof to the holders at positions where the opposite ends are in offset from respective rotation centers of the holders. The joint member has an arm portion and two joint portions which are provided on opposite ends of the arm portion and are respectively connected to the holders, wherein each joint portion is bent into an L shape in the same direction with respect to a longitudinal direction of the arm portion.
It is preferable that a wire for sending electrical signals responsive to vibration of the diaphragm to the body section is drawn from an aperture formed in each holder at a position including the rotation center of the holder.
It is preferable to provide a circuit board to which one end of each of the wires drawn from the diaphragms is connected, and apertures in the circuit board, for putting the wires therethrough and winding the wires on the circuit board.
According to the present invention, the voice recorder equipped with the right-and-left pair of microphones can change the microphones between the inward position (X-Y configuration) with little phase difference and the outward position (A-B configuration), without any intricate operation or complicated structure.
The above and other objects and advantages of the present invention will be more apparent from the following detailed description of the preferred embodiments when read in connection with the accompanying drawings, wherein like reference numerals designate like or corresponding parts throughout the several views, and wherein:
As shown in
In a front position of the body section 11 having the aforementioned shape, as shown in
Of the body section 11 set in the front position, upper and lower surfaces that face in the height-direction (Z-direction) are prescribed as a top surface 11A and a bottom surface 11B, respectively. Two sides that face in the longitudinal direction (X-direction) of the body section are prescribed as a front surface 11C and a back surface 11D, respectively, and other two sides that face in the width-direction (Y-direction) of the body section are prescribed as a left side surface 11E and a right side surface 11F, respectively.
An operating portion 13 and a displaying portion 14 are on the top surface 11A. The operating portion mainly includes, for example, a record button, a play button, a stop button, a selection button, and a cursor-movement button. The cursor-movement button, which moves the cursor in an operating screen on the displaying portion 14, is used to mainly select various kinds of menu items and folders storing the voice data.
The displaying portion 14, for example, is a liquid crystal display (LCD), which displays mainly the names of files and folders for record and playback, the audio level at playback, and operating screens for various kinds of settings. A dial 15 to adjust the audio level is on the right side surface 11F and jacks 16 to mount an earphone and an external microphone are on the left side surface 11E. And a card slot (not illustrated) to accommodate a memory card to store the data is on the left side surface 11E.
The microphones 12R and 12L are placed on the front surface 11C. The microphone 12L is for the left direction and the microphone 12R for the right. Each microphone 12R, 12L is provided with a diaphragm 18 collecting voices and a case 19 accommodating the diaphragm 18. The case 19 has an approximately cylindrical shape, and the diaphragm 18 is unitized integrally with, for example, a converter which converts vibration of the diaphragm 18 into an electrical signal. An open end side of the case 19 is provided with a head cover which is made, for example, of a metal mesh board, for protecting the internal diaphragm 18.
The diaphragm 18 is made of a metal foil and a synthetic resin film which have an approximately round shape. One surface of the diaphragm 18 is a sound-collecting surface to face the sound source, and an axis perpendicular to the sound-collecting surface is a sound-collecting axis SAX in each microphone 12R, 12L. The sound-collecting axis SAX coincides with the axial direction of the cylindrical case 19.
[Changing the Position of Each Microphone 12R, 12L]
A couple of holders 21 holding the pair of microphones 12R and 12L are provided on the front surface 11C, respectively. Base-ends of the microphones 12R and 12L are fixed to the respective holders 21. In the present embodiment, the holder 21 is formed integrally with the case 19. However, the holder 21 does not need to be formed integrally with the case 19.
Each holder 21 is of a circular shape, a center location of which is a rotation center HO (refer to
Turning each holder 21 causes the position of each microphone 12R, 12L to change between a position shown in
In general, the inward position shown in
The most ideal arrangement in the inward position is the position where the right and left microphones 12R and 12L intersect at respective centers of the diaphragms 18. In this position, the right-and-left phase difference can be reduced to zero. The center of the diaphragm 18 is the center DO of the circular surface of the diaphragm 18, which is on the sound-collecting axis SAX, as shown in
On the other hand, the outward position (A-B configuration) is the position where the sounds including neighboring environment sounds can be collected in addition to the particular sound source. In the outward position of this embodiment, with the body section in the front position, the right and left microphones 12R and 12L are in the same height in the Z-direction, as shown in
In addition, assuming that a plane perpendicular to both of the parallel rotation axes RAX, each of which extends across each rotation center HO of the corresponding holder 21, is referred to as a vertical plane (Y-Z plane), each sound-collecting axis SAX is, in the inward position and the outward position, parallel to a horizontal plane (X-Y plane) which is perpendicular to the vertical plane (Y-Z plane).
[Position of the Rotation Axis RAX of the Holder 21 in the Height-Direction (Z-Direction)]
In addition, as shown in
This offset arrangement makes it possible to avoid interference between the cases 19, even while the microphones 12R and 12L are set close to each other in the width-direction (Y-direction). As shown in
In addition, this offset arrangement allows the change between the inward position where the phase difference is reduced due to the intersection of the cases 19, and the outward position where the sound-collecting axes SAX do not intersect.
In addition to the offset arrangement of each microphone 12R, 12L on the holder 21, the holders 21 are staggered so as to make the rotation axes apart from each other in the height-direction (Z-direction). Thereby, it becomes possible to adopt the arrangement for allowing the cases 19 to intersect each other even with a greater diameter of the cases 19, or the like, and thus improve the design flexibility.
In addition, as shown in
The offset distance of each microphone 12R, 12L to the corresponding holder 21 and the distance in the height-direction between the rotation axes RAX, each extending across the rotation center HO of each holder 21, are determined as follows, specifically. First, in the vertical plane (Y-Z plane) which is perpendicular to both of the rotation axes RAX, the distance in the height-direction (Z-direction) between the rotation axes RAX of the holders 21 is designated by PV. In order to change the position of each microphone 12R, 12L between the inward position where the cases 19 of the microphones 12R and 12L intersect and the outward position where the microphones 12R and 12L are in the same height, as in this embodiment, the distance PV is determined as follows.
First, in the outward position, an AB line shown in
PV=(D/2+D/2+C)/2 Formula (1)
Wherein, D is a diameter of each microphone 12R, 12L and C is a clearance between the cases 19 of the microphones 12R and 12L.
The rotation axes RAX of the holders 21 are spaced the distance PV from each other, and each rotation axis RAX is placed at the same distance from the AB line in the height-direction. The distance in the height direction (Z-direction) from the AB line to the rotation axis RAX of each holder 21 becomes PV/2, accordingly. The clearance C, which is a given value, is preferably set as small as possible insofar as the cases 19 do not contact each other.
In this embodiment, the microphones 12R and 12L are brought into the same height in the outward position turned by 180 degrees from the inward position. In this case, PV/2 must be equal to the offset distance OFS of the sound-collecting axis SAX from the rotation axis RAX on each holder 21: OFS=PV/2. Accordingly, determining the distance PV in accordance with formula (1) above can lead to determining the offset distance OFS.
Spacing the rotation axes RAX of the holders 21 by the distance PV apart from other in the height-direction thus allows the cases 19 of the microphones 12R and 12L to intersect each other in the inward position, while enabling setting the microphones 12R and 12L in the same height in the outward position.
[Position of the Rotation Axis RAX (the Rotation Center HO) of the Holders 21 in the Width-Direction (Y-Direction)]
And as shown in
PH=2L·cos(90°−θ/2) Formula (2)
Wherein, L is a length of each sound-collecting axis SAX from the intersection point XP to the rotation axis RAX that extends across the rotation center HO of the holder 21. θ is an angle between the two intersecting sound-collecting axes SAX.
Thus, the rotation axes RAX of the holders 21 are spaced the distance PH apart and at the same distance from the intersection point XP in the width-direction (Y-direction). That is, the distance between a straight line XPL through the intersection point XP and the rotation axis RAX of each holder 21 in the width-direction (Y-direction) becomes PH/2.
In this embodiment, in order to set the right-and-left phase difference to zero in the inward position, the diaphragms 18 of the microphones 12R and 12L are arranged to intersect each other so as the respective centers DO overlap as viewed from the Z-direction. Therefore, the point at which the centers DO of the diaphragms 18 overlap coincides with the intersection point XP, so that the position in the width-direction (Y-direction) of the rotation axis RAX of each holder 21 is determined by formula (2) above.
[Mounting Structure for the Holder]
As shown in
As shown in
[Interlocking Mechanism for the Holder]
As shown in
The joint member 31 has an arm 31A and joints 31B which are at opposite ends of the arm 31A and are connected to the holders 21, respectively. Each joint 31B is fixed to each holder 21 by a joint-pin 32. As shown in
As shown in
In each holder 21, a wire-drawing aperture 38 to draw out the wires 37 from each case 19 is formed at a position that includes the rotation center HO. The wire 37 is a signal line which sends electrical signals responsive to the vibration of the diaphragm 18 to the body section 11. While the holders 21 are turning, the wires are hard to be twisted if the wire-drawing apertures 38 are formed at the respective rotation centers HO of the holders 21, as compared with a case where the wire-drawing apertures 38 being formed away from the rotation center HO.
Also, in this embodiment, the following configuration is devised so that the wires 37 and the joint member 31 will not intersect while the holders 21 are turning. Specifically, each joint 31B of the joint member 31 is bent into an L shape and in the same direction with respect to the longitudinal direction of the arm 31A. The joint member 31 of such a shape is attached to the holders 21 in a mounting position as shown in
Applying the devised geometric configuration of the joints 31B to the joint member 31 and setting the joint member 31 in the mounting position to the holders 21, as shown in
Also, the joint member 31 is mounted so that the interlocked holders 21 can turn in the same direction. That is, in
Also, in
The torque hinge 41 in this embodiment is provided to stabilize each microphone 12R, 12L in either of the inward and outward positions. When the holder 21 starts to turn from either of the inward and the outward positions to the other position, the torque hinge 41 gives the turning force to each holder 21 in a predetermined manner. Specifically, the torque hinge 41 gives the holders 21 the turning force in a direction urging the holders 21 to return to the initial position before the turning until the holders 21 arrive at a predetermined rotational position. Whereas, the torque hinge 41 gives the turning force in a direction urging the folder 21 to move to the other position after the holders 21 arrived at the predetermined rotational position. This action of the torque hinge 41 contributes to stabilizing the microphones 12R and 12L either in the inward position or in the outward position.
The torque hinge 41 is provided with a pivot member 42 and a fixed portion 43 which is fixed to holder 21. The fixed portion 43 in this embodiment has a reed shape. The pivot member 42 is of a circular shape in section, and is provided with a convex contact portion 42A sticking out from the periphery of the pivot member 42 in the Y-direction which is perpendicular to the rotation axis RAX. The torque hinge 41 is attached to the holder 21 in a position where the rotation center of the pivot member 42 and the rotation center HO of the holder 21 are aligned. The pivot member 42 is rotatable relative to the fixed portion 43.
A turn-regulating portion 43A, with which the contact portion 42A is brought into contact, is provided on the fixed portion 43. One side of the contact portion 42A is brought into contact with the turn-regulating component 43A in the inward position, whereas the other side of the contact portion 42A is brought into contact with the turn-regulating portion 43A in the outward position where the holder 21 turns 180 degrees from the inward position. This way, the turn-range of the holder 21 between the inward position and the outward position is restricted within 180 degrees.
The holder 21 has an attaching member 46, and the torque hinge 41 is incorporated in the holder 21 by fitting the pivot member 42 to the aperture 46A of the attaching member 46. The clamping plate 33 is arranged between the attaching member 46 and the torque hinge 41. The torque hinge 41 is attached to the clamping plate 33 with a gap between the clamping plate 33 and the fixed portion 43, allowing entrance of the joint member 31 into the gap.
The operation of the configuration as set forth above will be described with reference to
As shown in
In the case of changing the microphones 12R and 12L from the inward position shown in
Since the outward position is the position turned by 180 degrees from the inward position, the sound-collecting axis SAX of each microphone 12R, 12L in the outward position is parallel to the X-Y plane, as in the inward position. In the outward position, the sound-collecting axes SAX of the microphones 12R and 12L do not intersect each other but are oriented outward from each other. In addition, in this embodiment, the microphones 12R and 12L are in the same height in the outward position.
As described above, each sound-collecting axis SAX of each microphone 12R, 12L is arranged offset from the individual rotation axis RAX of each holder 21 in the direction that the sound-collecting axes SAX are spaced apart from each other in the inward position. This allows the cases 19 of the microphones 12R and 12L to intersect each other in the inward position to reduce the right-and-left phase difference.
Also, because each holder 21 can turn between the inward position and the outward position turned by 180 degrees from the inward position, it is possible to select the inward position or the outward position merely by the turning operation. Thus, the voice recorder 10 in this embodiment facilitates the operation and simplifies the structure to change the position of each microphone 12R, 12L, as compared to the prior art that requires sliding one microphone to enable intersecting with the other.
In this embodiment, in addition, the diaphragms 18 of the microphones 12R and 12L intersect at the centers thereof in the inward position. This provides a zero right-and-left phase difference.
Furthermore, in this embodiment, the offset distance OFS, which is the distance from the rotation axis RAX of each holder 21 to the sound-collecting axis SAX, is equal between the right and left microphones 12R and 12L, though the offset direction is by 180 degrees but the same distance, in the right-and-left microphone 12R, 12L. In the outward position turned by 180 degrees from the inward position, accordingly, this can make the same height of each microphone 12R, 12L in the Z-direction.
As shown in
Turning each microphone 12R, 12L by 90 degrees from the inward position shown in
Thus, the holders 21 are interlocked through the interlocking mechanism, so that there is no need for turning each holder 21 individually. The change between the inward position and the outward position can be performed with a single action.
Furthermore, in each holder 21, the wires 37 are drawn from the wire-drawing aperture 38 formed at the position including the rotation center HO. As a result, since the wires 37 are located near to the rotation center HO, the wires 37 are hard to be twisted when each holder 21 and each microphone 12R, 12L are turned. This can suppress breaking the wires 37.
In addition, as described above, at the opposite ends of the arm 31A, the joint member 31 has the joints 31B bent into an L shape and in the same direction with respect to the longitudinal direction of the arm 31A. And, as shown in
Subsequently, within the 180-degree turning range from the inward position shown in
[Variation Devising a Method for Fixing the Wires]
As shown in
One end 37A of each wire 37 is fixed to the circuit board 26A by soldering. As mentioned above, turning the holder 21 results some twist of the wires 37 even where the wires 37 are drawn out from the wire-drawing aperture 38 formed in the position including the rotation center HO of the holder 21. When the wire 37 is twisted, a force such as tension exerts on the wire 37, and the force will concentrate on one end 37A as a relatively weak portion of the wire 37. This can cause breakage of the wire 37.
Addressing this problem, a wire-winding aperture 26B to wind the wires 37 on the circuit board 26A is formed in the circuit board 26A. The wire rod 37, passing through the wire-winding aperture 26B, is wound on the circuit board 26A. In this state, one end 37A is fixed to the circuit board 26A by soldering. Even if the tension exerts on the wire 37 with the holder 21 being turned, this devise makes the tension dispersed over a wound portion of the wire 37 on the circuit board 26A, which suppresses the tension from gathering on one end 37A. This prevents breaking the wires 37.
As shown in
[Variation in the State of Intersection of the Microphones]
In the above embodiment, the microphones 12R and 12L do not necessarily intersect at the centers DO of the diaphragms 18 but may intersect at an edge of each diaphragm 18, as shown in
[Aspects of the Interlocking Mechanism]
With regard to the aspects of the interlocking mechanism for the holders 21, the system illustrated in the above embodiment is constituted of the joint member 31 having a stick-like shape. The shape of joint member 31, however, may also be another shape, not limited to the above example. The interlocking mechanism may also be constructed using gears or the like in place of the joint member 31. In addition, the holders 21 and the interlocking mechanism may be driven by a motor.
Also, the interlocking mechanism may not be necessary. Without the interlocking mechanism, it is necessary to turn each holder 21 individually. Also in this case, however, the position of each microphone can be changed merely by the tuning operation. In comparison with the prior art which needs the sliding operation in addition to the turning operation, the effects of simplifying the operation and the construction can be obtained in this case.
The present invention is not limited to the above embodiment, but appropriate changes are possible without departing from the purpose of the present invention, including a combination of the above embodiment and variations, for example.
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