Patent Publication Number: US-10321214-B2

Title: Microphone

Description:
TECHNICAL FIELD 
     The present invention relates to a microphone. 
     BACKGROUND ART 
     Microphones for conferences are mounted to microphone stands placed on desks, and are used by conference attendees (see, for example, Japanese Patent Application Publication No. 2008-11165). Such microphones are mountable to and dismountable from microphone stands. A microphone for a conference includes a microphone unit, an output connector, and a microphone housing (connector case). The microphone unit is a condenser microphone unit configured to output sound signals in response to sound waves from a sound source, for example. 
     The output connector is connected with an input connector (receptacle) of the microphone stand, which will be described below, and outputs sound signals from the microphone unit to the microphone stand. The output connector includes pin plugs which conform to the JEITA Standard RC-5236 “Circular connectors, latch lock type for audio equipment,” for example. The output connector includes a cylindrical base, a first pin for grounding, a second pin for sound signals at the hot side, and a third pin for sound signals at the cold side. 
     The connector case accommodates the output connector and serves as the ground line for sound signals. The connector case is composed of metal and has a shape of a cylinder. The connector case includes a latch groove to which a latch claw, which will be described below, fits. The latch groove is disposed on the inner circumferential surface at the base end portion of the connector case. The “base end portion” is an end portion of the connector case and is to be inserted in a connector-supporting hole, as described below. The output connector is accommodated in the connector case and is fixed with screws. 
     The microphone stand supports the microphone and outputs sound signals from the microphone to external devices such as mixers. The microphone stand includes the input connector to be connected to the output connector of the microphone. 
     The input connector is a socket receptacle which conforms to the JEITA Standard RC-5236 “Circular connectors, latch lock type for audio equipment”, for example. The input connector includes a housing, a pin-receiving portion, a connector-supporting hole, and a latch-locking mechanism. 
     The housing supports the pin-receiving portion and the latch-locking mechanism. The housing is composed of metal and has a shape of a cylinder, for example. The pin-receiving portion holds three pins which connect to the first to third pins of the output connector. The pin-receiving portion is composed of synthetic resin and has a shape of a cylinder. The pin-receiving portion is fixed to the inside of the housing. The connector-supporting hole supports the base end portion of the connector case. The connector-supporting hole is a cylindrical space defined by the inner circumferential surface of the housing and the outer circumferential surface of the pin-receiving portion. 
     The latch-locking mechanism fixes the base end portion of the connector case into the connector-supporting hole. The latch-locking mechanism includes a latch claw and a release lever. The latch claw fixes the connector case to the input connector. The latch claw is disposed on the outer circumferential surface of the pin-receiving portion in the connector-supporting hole. The latch claw can advance and retract in the radial direction of the pin-receiving portion. The latch claw is electrically connected with a ground line of the input connector. The release lever moves the latch claw inwardly to the radial direction of the pin-receiving portion. 
     The base end portion of the connector case is inserted in the connector-supporting hole in the input connector when the microphone is mounted to the microphone stand. The latch claw of the input connector is fit into the latch groove of the connector case. That is, the microphone is fixed to the input connector through one latch and the latch groove. The microphone is no longer movable in the longitudinal direction of the microphone after fitting of the latch claw into the latch groove. The latch claw is then electrically connected with the latch groove (connector case) and serves as the ground line for sound signals. 
     The latch claw retracts from the latch groove when an operator of the microphone presses down the release lever. As a result, the microphone is dismounted from the microphone stand. As described above, the microphone is mountable to and dismountable from the microphone stand. 
     SUMMARY OF INVENTION 
     Technical Problem 
     In order to facilitate mounting to and dismounting from the microphone stand of the microphone, the diameter of the connector-supporting hole is larger than the outer diameter of the base end portion of the connector case. When the microphone is mounted to the microphone stand, a gap is formed between the outer circumferential surface at the base end portion of the connector case and the inner circumferential surface of the housing. Such a gap generates backlash of the microphone relative to the microphone stand. That is, when a desk is shaken on which the microphone stand is placed, for example, the microphone pendulums on the latch claw as a pivot within the gap. As a result, the position of the tip of the microphone is not securely fixed, for the goose neck type microphones having a long length, for example. 
     When the backlash of the microphone is generated, the vibration of a desk, for example, is transmitted to the microphone, and the microphone unit generates noise signals (noise) due to the vibration and outputs them. When the backlash of the microphone is generated, the electric connection of the latch claw with the latch groove is no longer stable, and the ground line of the microphone becomes unstable. Thus, the electromagnetic waves from the exterior of the microphone intrude into the connector case (base end portion) through the gap between the connector case and the connector. As a result, the microphone unit generates noise due to electromagnetic waves and outputs them. Furthermore, when the ground line for the microphone becomes unstable, the voltage of the phantom power supplied to the microphone unit fluctuates positively and negatively. As a result, failure, damage, and malfunction of semiconductors and LEDs included in the microphone may occur. 
     An object of the present invention is to solve the problem described above and to provide a microphone having restrained backlash relative to the microphone stand with a simple structure. 
     Solution to Problem 
     The microphone according to the present invention is a microphone to be inserted in a connector-supporting hole of a microphone stand, and includes a microphone unit, an output connector configured to output sound signals from the microphone unit to the exterior, a case accommodating the output connector, and an elastic member configured to be disposed in the connector-supporting hole while a portion of the case is inserted in the connector-supporting hole. 
     Advantageous Effects of Invention 
     The microphone according to the present invention can restrain backlash relative to microphone stand with a simple structure. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is an external view of an embodiment of a microphone according to the present invention. 
         FIG. 2  is a cross-sectional view of a connecting portion of the microphone of  FIG. 1  taken along the line A-A. 
         FIG. 3  is a schematic view illustrating an exemplary use of the microphone in  FIG. 1 . 
         FIG. 4  is a partial cross-sectional view of an input connector of a microphone stand of  FIG. 3 . 
         FIG. 5  is a view of the input connector in  FIG. 4  viewed along arrow B. 
         FIG. 6  is a cross-sectional view of the connector portion of the microphone mounted to the microphone stand. 
         FIG. 7  is an enlarged cross-sectional view of the elastic member in  FIG. 6 . 
         FIG. 8  is a cross-sectional view illustrating another embodiment of the microphone according to the present invention. 
         FIG. 9  is a cross-sectional view taken along the line C-C of the microphone in  FIG. 8 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Microphone ( 1 ) 
     Embodiments of the microphone according to the present invention (hereinafter referred to as “the first embodiment”) will now be described with reference to the attached drawings. 
     Structure of Microphone ( 1 ) 
       FIG. 1  is an external view of an embodiment of a microphone according to the present invention. 
     A microphone  1  collects sound waves from a sound source and outputs electric signals corresponding to the sound waves. The microphone  1  is a goose neck type microphone mounted to a microphone stand  4 , which will be described below. The microphone  1  is mountable to and dismountable from the microphone stand  4 . The microphone  1  includes a sound collecting portion  10 , a coupling portion  20 , a connecting portion  30 , and a microphone cable (not shown). 
     In the description below, the direction to the upper side of  FIG. 1  is referred to as the upper direction, and the direction to the lower side of  FIG. 1  is referred to as the lower direction. 
     The sound collecting portion  10  is directed to a sound source, and collects sound waves from the sound source. The sound collecting portion  10  includes a microphone unit  11  and a microphone case  12 . The microphone unit  11  is configured to output electric signals corresponding to the sound waves received from the sound source. The microphone unit  11  is a condenser microphone unit, for example. The microphone case  12  accommodates the microphone unit  11 . 
     The coupling portion  20  couples the sound collecting portion  10  with the connecting portion  30 . The coupling portion  20  includes a first case  21 , a first flexible pipe  22 , a joint  23 , a second flexible pipe  24 , and a second case  25 . 
     The first case  21  couples the sound collecting portion  10  with the first flexible pipe  22 . The first flexible pipe  22  and the second flexible pipe  24  are bent to adjust the position of the sound collecting portion  10 . The joint  23  couples the first flexible pipe  22  with the second flexible pipe  24 . The second case  25  couples the second flexible pipe  24  with the connecting portion  30 . 
     The sound collecting portion  10  is coupled to one end of the first flexible pipe  22  through the first case  21 . The other end of the first flexible pipe  22  is coupled to one end of the second flexible pipe  24  through the joint  23 . The other end of the second flexible pipe  24  is coupled to the connecting portion  30  through the second case  25 . 
       FIG. 2  is a cross-sectional view taken along the line A-A of the connecting portion  30  in  FIG. 1 . 
     The connecting portion  30  connects the microphone unit  11  to an input connector of the microphone stand  4 , which will be described below. The connecting portion  30  includes a connector case  31 , a circuit board  32 , an output connector  33 , and an elastic member  34 . 
     The connector case  31  accommodates the circuit board  32  and the output connector  33 . The connector case  31  is composed of metal and has a substantially cylindrical shape. The connector case  31  is an exemplary case in the present invention. The connector case  31  includes a groove  311  and a latch groove  312 . The groove  311  fixes the position of the elastic member  34  on the connector case  31 . The groove  311  is disposed on the outer circumferential surface at the lower end of the connector case  31 , in a shape of a ring in the circumferential direction of the connector case  31 . The latch groove  312  is disposed on the inner circumferential surface at the lower end of the connector case  31 . The function of the latch groove  312  will be described below. 
     The circuit board  32  is composed of synthetic resin, and has a shape of a rectangular plate, for example. The circuit board  32  includes a circuit, such as a balanced transmission circuit (not shown) outputting sound signals from the microphone unit  11  to the output connector  33 . The circuit board  32  is accommodated in the connector case  31 . 
     The output connector  33  outputs sound signals from the circuit board  32 . The output connector  33  is a pin plug which conforms to the JEITA Standard RC-5236 “Circular connectors, latch lock type for audio equipment,” for example. The output connector  33  includes a cylindrical base  331 , a first pin for grounding (not shown), a second pin  332  at the hot side of sound signals, and a third pin  333  at the cold side of sound signals. The output connector  33  is accommodated at the lower end of the connector case  31 , and is fixed by a screw. 
     The elastic member  34  is composed of synthetic resin such as nitrile rubber or silicone rubber having elasticity. The elastic member  34  is a circular O-ring in the cross-sectional view. The inner diameter of the elastic member  34  is smaller than the outer diameter of the groove  311  of the connector case  31 . The elastic member  34  is fit (disposed) into groove  311  of the connector case  31 . That is, the elastic member  34  is disposed on the outer circumferential surface of the connector case  31 . The outer diameter of the elastic member  34  is larger than that of the connector case  31 . Thus, a portion of the elastic member  34  protrudes from the outer circumferential surface of the connector case  31 . The diameter of an imaginary circle C 1  (the outer diameter of the elastic member  34  in the present embodiment) circumscribing the elastic member  34  is larger than the inner diameter of a housing  51  (see  FIG. 4 ) of an input connector  50  for the microphone stand  4 , which will be described below. 
     The elastic member in the present invention is not limited to an O-ring. That is, the elastic member may be a cylindrical tube, for example. 
     The microphone cable transmits the sound signals from the microphone unit  11  to the circuit board  32 . The microphone cable is disposed in the coupling portion  20  and is connected with the microphone unit  11  and the circuit board  32 . 
     Microphone Stand 
     The microphone stand  4  will now be described to which the microphone according to the present invention is mounted. 
     Structure of Microphone Stand 
       FIG. 3  is a schematic view illustrating an exemplary use of the microphone  1 . 
       FIG. 3  illustrates the microphone stand  4  with the microphone  1  mounted thereto. 
     The microphone stand  4  holds the microphone  1  standing on it. The microphone stand  4  includes a base housing  40 , an input connector  50 , and an external output connector  60 . 
     The base housing  40  supports the microphone  1  through the input connector  50 . The base housing  40  is composed of metal, and is flat and hollow. The base housing  40  includes a first connector mounting hole  40   h   1  and a second connector mounting hole  40   h   2 . The first connector mounting hole  40   h   1  is disposed on the upper face (the upper face in  FIG. 3 ) of the base housing  40 . The second connector mounting hole  40   h   2  is disposed on the rear face (the right side face in  FIG. 3 ) of the base housing  40 . 
       FIG. 4  is a partial cross-sectional view of the input connector  50 . 
       FIG. 5  is a view of the input connector  50  viewed along from the perspective of an arrow B in  FIG. 4 . 
     For convenience of explanation, the two dot chain lines in  FIG. 5  illustrate the outer diameter of the elastic member  34  after the microphone  1  has been mounted to the microphone stand  4 . 
     The input connector  50  couples with the output connector  33  of the microphone  1  to output the sound signals from the microphone  1  to the external output connector  60  (see  FIG. 3 ). The input connector  50  is a socket receptacle which conforms to the JEITA Standard RC-5236 “Circular connectors, latch lock type for audio equipment,” for example. The input connector  50  is mounted into the first connector mounting hole  40   h   1  of the base housing  40 . The input connector  50  includes the housing  51 , a pin-receiving portion  52 , a connector-supporting hole  53 , and a latch-locking mechanism  54 . 
     The housing  51  accommodates the pin-receiving portion  52 . The housing  51  is composed of metal and has a shape of a cylinder, for example. The housing  51  is an exemplary input connector housing in the present invention. The inner diameter of the upper portion of the housing  51  is larger than that of the lower portion of the housing  51 . The housing  51  includes a flange portion  511  having a rectangular shape in the top view. The flange portion  511  fixes the housing  51  to the base housing  40 . The flange portion  511  is disposed on the outer circumferential surface of the upper portion of the housing  51 . 
     The pin-receiving portion  52  connects with the output connector  33  of the microphone  1 . The pin-receiving portion  52  is composed of synthetic resin and has a shape of a cylinder. The pin-receiving portion  52  is disposed within the housing  51 . The outer circumferential surface of the upper portion of the pin-receiving portion  52  faces the inner circumferential surface of the upper portion of the housing  51 . The lower portion of the pin-receiving portion  52  is fit into the lower portion of the housing  51 . The pin-receiving portion  52  includes a first pin (not shown), a second pin  522 , a third pin  523 , and a ground terminal  524 . The first pin, the second pin  522 , and the third pin  523  protrude downwardly from the pin-receiving portion  52 . As shown in  FIG. 5 , one end of the ground terminal  524  is disposed on the outer circumferential surface of the upper portion of the pin-receiving portion  52 . This end of the ground terminal  524  can advance and retract in the radial direction of the pin-receiving portion  52 . That is, this end of the ground terminal  524  protrudes into the connector-supporting hole  53 , which will be described below. As shown in  FIG. 4 , the other end of the ground terminal  524  protrudes downwardly from the pin-receiving portion  52 . 
     The connector-supporting hole  53  supports the bottom portion of the connector case  31 . The connector-supporting hole  53  is a cylindrical space defined by the inner circumferential surface of the upper portion of the housing  51  and the outer circumferential surface of the upper portion of the pin-receiving portion  52 . That is, the connector-supporting hole  53  is disposed between the housing  51  and the pin-receiving portion  52 . The inner diameter of the upper portion of the housing  51  is larger than the outer diameter of the connector case  31  of the microphone  1  (see  FIG. 2 ), and is smaller than the outer diameter of the elastic member  34  of the microphone  1 . In other words, the outer diameter (an imaginary circle C 1  circumscribing the elastic member  34 ) of the elastic member  34  is larger than the inner diameter (the outer diameter of the connector-supporting hole  53 ) of the housing  51 . 
     The latch-locking mechanism  54  fixes the connector case  31  into the connector-supporting hole  53 . The latch-locking mechanism  54  includes a latch claw  541  and a release lever  542 . The latch claw  541  fixes the connector case  31  into the connector-supporting hole  53 . The latch claw  541  is disposed on the outer circumferential surface of the upper portion of the pin-receiving portion  52 . The latch claw  541  can advance and retract in the radial direction of the pin-receiving portion  52 . The latch claw  541  is electrically connected to the ground terminal  524 . The release lever  542  moves the latch claw  541  into the pin-receiving portion  52 . The release lever  542  protrudes from the upper face  512  on the housing  51 . 
     Referring now back to  FIG. 3 , the external output connector  60  outputs the sound signals from the input connector  50  to external devices such as mixers (not shown). The external output connector  60  has the same configuration as the input connector  50 . That is, the external output connector  60  includes a first pin (not shown), a second pin  622 , a third pin  623 , and a ground terminal  624 . The external output connector  60  is mounted into the second connector mounting hole  40   h   2  in the base housing  40 . A plug  7  is inserted in the external output connector  60 . The plug  7  is connected to external devices through a cable  8 . 
     The first pin of the external output connector  60  is electrically connected with the first pin of the input connector  50 . The second pin  622  of the external output connector  60  is electrically connected with the second pin  522  of the input connector  50 . The third pin  623  of the external output connector  60  is electrically connected with the third pin  523  of the input connector  50 . The ground terminal  624  of the external output connector  60  is electrically connected with the ground terminal  524  of the input connector  50 , and is connected with the ground of the external devices. That is, the ground terminal  524  and the latch claw  541  of the input connector  50  are grounded through the ground terminal  624  of the external output connector  60 . 
     Mounting to and Dismounting from Microphone Stand of Microphone ( 1 ) 
     Referring to  FIGS. 2 and 4 , mounting to and dismounting from the microphone stand  4  of the microphone  1  will now be described. 
     The microphone  1  is mounted to the microphone stand  4  by inserting the lower end of the connector case  31  into the connector-supporting hole  53  of the input connector  50 . That is, the microphone  1  is mounted to the microphone stand  4  by inserting the microphone  1  into the connector-supporting hole  53 . 
     When the lower end of the connector case  31  is inserted in the connector-supporting hole  53  of the input connector  50 , the first pin, the second pin  332 , and the third pin  333  of the output connector  33  of the microphone  1  are inserted in the pin-receiving portion  52 . Then, the ground terminal  524  and the latch claw  541  are pressed onto the inner circumferential surface of the connector case  31 , and retract into the pin-receiving portion  52 . Then, the elastic member  34  comes into contact with the inner edge portion at the upper end of the housing  51 . 
     The elastic member  34  has an upper side portion and a lower side portion. After contact with the housing  51 , the lower side portion of the elastic member  34  is pressed to the connector case  31  by the housing  51  and deforms to be forced (inserted) in the connector-supporting hole  53 . The lower side portion of the elastic member  34  bites into the gap (connector-supporting hole  53 ) between the outer circumferential surface of the connector case  31  and the inner circumferential surface of the housing  51 . As described above, the elastic member  34  has a shape of a circular O-ring in a cross-sectional view. That is, the outer diameter of the elastic member  34  becomes smaller in the direction from the middle portion to lower portion of the elastic member  34 . Thus, the lower portion of the elastic member  34  can be readily inserted in the connector-supporting hole  53 . 
     Then, the latch claw  541  of the input connector  50  is fit into the latch groove  312  of the connector case  31 . As a result, the microphone  1  is mechanically coupled to the microphone stand  4  and mounted erect. The first pin of the output connector  33  in the microphone  1  is electrically connected to the first pin of the input connector  50 . The second pin  332  of the output connector  33  in the microphone  1  is electrically connected with the second pin  522  of the input connector  50 . The third pin  333  of the output connector  33  in the microphone  1  is electrically connected with the third pin  523  of the input connector  50 . 
       FIG. 6  is a cross-sectional view of a portion of the output connector  33  of the microphone  1  mounted to the microphone stand  4 .  FIG. 6  illustrates the cross-section of a portion of the connector case  31  and a portion of the housing  51 . 
     While the lower end portion of the connector case  31  is inserted in the connector-supporting hole  53 , the latch claw  541  is fit in the latch groove  312  to regulate the movement of the connector case  31  in the longitudinal direction (the vertical direction in  FIG. 6 ). The latch claw  541  comes into contact with the latch groove  312 . The ground terminal  524  (see  FIG. 5 ) is kept retracted in the pin-receiving portion  52  by the inner circumferential surface of the connector case  31 . That is, the connector case  31  is electrically connected with the ground terminal  524  and the latch claw  541 . As a result, the connector case  31  is connected with the ground of external devices through the ground terminal  524  and the latch claw  541 . In other words, the ground terminal  524  and the latch claw  541  form a ground line for the microphone  1  through the electrical connection with the connector case  31 . 
     While the lower end portion of the connector case  31  is inserted in the connector-supporting hole  53 , the elastic member  34  fitted in the groove  311  of the connector case  31  is disposed near the upper face  512  of the housing  51 . That is, while the bottom portion of the connector case  31  is inserted in the connector-supporting hole  53 , the lower side portion of the elastic member  34  is compressed by the housing  51  against the connector case  31  in the entire circumference and is deposed in the connector-supporting hole  53 . While the lower end portion of the connector case  31  is inserted in the connector-supporting hole  53 , the upper side portion of the elastic member  34  is exposed from the connector-supporting hole  53 . 
       FIG. 7  is an enlarged cross-sectional view of the elastic member  34  in  FIG. 6 . 
       FIG. 7  schematically illustrates compressive force received by the elastic member  34  from the housing  51  with an outlined arrow. 
     The connector case  31  is pressed by the lower side portion of the elastic member  34  toward the center of the connector case  31  in the radial direction in the entire circumference as the lower side portion of the elastic member  34  is compressed by the housing  51 . As a result, the elastic member  34  regulates the movement of the connector case  31  in the radial direction (the horizontal direction in  FIG. 7 ). 
     As described above and shown in  FIG. 6 , the connector case  31  is fixed by the elastic member  34  at the upper end of the connector-supporting hole  53 . The connector case  31  is not movable in the radial direction of the connector case  31 . The connector case  31  is fixed by the latch claw  541  and the latch groove  312  at the lower end of the connector-supporting hole  53 . The connector case  31  is not movable in the longitudinal direction (the vertical direction) of the connector case  31 . Even when a desk with the microphone stand  4  placed thereon is shaken, the microphone  1  does not pendulum on the latch claw  541  as a pivot. That is, the microphone according to the present invention can restrain the backlash relative to a microphone stand more effectively than the traditional microphones fixed to an input connector only with a latch claw fitted in a latch groove. As a result, stable electrical connection is established between the connector case  31  and the latch claw  541  and between the connector case  31  and the ground terminal  524 . A stable ground line for the microphone  1  is thereby established. 
     Returning to  FIG. 6 , when an operator of the microphone  1 , for example, presses down the release lever  542 , the latch claw  541  is dismounted from the latch groove  312 . As a result, the microphone  1  is dismounted from the microphone stand  4 . As described above, the upper side portion of the elastic member  34  is exposed from the connector-supporting hole  53 . When the microphone  1  is dismounted from the microphone stand  4 , the lower side portion of the elastic member  34  thus can be drawn from the connector-supporting hole  53  (the gap between the outer circumferential surface of the connector case  31  and the inner circumferential surface of the housing  51 ). That is, the microphone  1  can be readily dismounted from the microphone stand  4 . 
     SUMMARY 
     In the microphone according to the embodiment described above, while a portion (the lower end) of the connector case  31  is inserted in the connector-supporting hole  53 , a portion (the lower side portion) of the elastic member  34  is disposed in the connector-supporting hole  53 . That is, the lower side portion of the elastic member  34  bites into the gap between the outer circumferential surface of the connector case  31  and the inner circumferential surface of the housing  51  of the input connector  50 . Thus, the connector case  31  is fixed by the elastic member  34 . The connector case  31  is not movable in the radial direction of the connector case  31 . In other words, the microphone according to the present invention restrains the backlash relative to a microphone stand more effectively than the conventional microphones fixed to an input connector only with a latch claw fit in a latch groove. As a result, the ground line for the microphone  1  becomes stable. 
     In addition, in the microphone according to the embodiment described above, while the lower end portion of the connector case  31  is inserted in the connector-supporting hole  53 , a portion (the upper side portion) of the elastic member  34  is exposed from the connector-supporting hole  53 . When the microphone  1  is dismounted from the microphone stand  4 , the lower side portion of the elastic member  34  thus can be readily dismounted from the connector-supporting hole  53 . When the microphone  1  is mounted to the microphone stand  4 , only a portion of the elastic member  34  is fit into the connector-supporting hole  53 . Thus, the microphone  1  can be readily mounted to the microphone stand  4 . That is, the microphone according to the present invention restrains the backlash relative to the microphone stand and facilitates mounting to and dismounting from the microphone stand of the microphone. 
     Furthermore, in the microphone according to the embodiment described above, the diameter of an imaginary circle C 1  circumscribing the elastic member  34  (the diameter of the elastic member  34 ) is larger than the inner diameter of the housing  51  of an input connector  50 . While the lower portion of the connector case  31  is inserted in the connector-supporting hole  53 , the lower side portion of the elastic member  34  is compressed by the housing  51  against the connector case  31 . That is, the connector case  31  is pressed by the lower side portion of the elastic member  34  toward the center of the connector case  31  in the radial direction in the entire circumference. As a result, the elastic member  34  regulates the movement of the connector case  31  in the radial direction. In other words, the microphone according to the present invention restrains the backlash relative to the microphone stand more effectively than the conventional microphones. 
     Furthermore, in the microphone according to the embodiment described above, the elastic member  34  is an O-ring disposed in the groove  311  disposed on the outer circumferential surface of the connector case  31 . Thus, the microphone according to the present invention restrains the backlash relative to the microphone stand with a simple structure. 
     Furthermore, in the microphone according to the embodiment described above, while the lower end portion of the connector case  31  is inserted in the connector-supporting hole  53 , the elastic member  34  fitted in the groove  311  of the connector case  31  is disposed near the upper face  512  of the housing  51  of the input connector  50 . That is, while the lower end portion of the connector case  31  is inserted in the connector-supporting hole  53 , a portion (the lower side portion) of the elastic member  34  disposed in the groove  311  is thereby disposed in the connector-supporting hole  53 , and a portion (the upper side portion) of the elastic member  34  is exposed from the connector-supporting hole  53 . As a result, the microphone according to the present invention restrains the backlash relative to the microphone stand, and facilitates mounting to and dismounting from the microphone stand of the microphone. 
     Furthermore, in the microphone according to the embodiment described above, while the lower end portion of the connector case  31  is inserted in the connector-supporting hole  53 , the elastic member  34  fitted in the groove  311  of the connector case  31  is disposed near the upper face  512  of the housing  51  of the input connector  50 . The output connector of the microphone and the input connector of the microphone stand are typically standard products such as those which conform to the JEITA Standard RC-5236. The microphone according to the present invention thereby restrains the backlash relative to the microphone stand, regardless of the form of the connector cases, such as a long connector case accommodating a circuit board or a transformer, and a connector case including a switch disposed on the outer circumferential surface. 
     Microphone ( 2 ) 
     Another embodiment of the microphone (hereinafter referred to as “the second embodiment”) will now be described, focusing on the differences from the first embodiment described above. The microphone in the second embodiment differs from the first embodiment in the position and shape of the elastic member. 
     Configuration of Microphone ( 2 ) 
       FIG. 8  is a cross-sectional view illustrating another embodiment of the microphone according to the present invention. 
       FIG. 9  is a cross-sectional view taken along the line C-C of the microphone in  FIG. 8 . 
     A microphone  2  includes a connector case  31   a  and at least one elastic member  34   a . The connector case  31   a  of the microphone  2  includes four through holes  31   ah , instead of the groove  311  of the connector case  31  of microphone  1  in the first embodiment. The through holes  31   ah  fix the elastic members  34   a . The through holes  31   ah  are disposed at the lower end of the connector case  31   a  and at an equal interval in the circumferential direction of the connector case  31   a.    
     The through holes in the present invention may be disposed at an equal interval in the circumferential direction of the connector case, and the number of the through holes is not limited to “four.” That is, the number of the through holes may be “three” or “six,” for example. 
     The elastic member  34   a  is composed of elastic synthetic resin, for example, nitrile rubber or silicone rubber. The elastic member  34   a  has a T shape in a cross-sectional view. The tip of the elastic member  34   a  has a shape of a hemisphere. The elastic member  34   a  is fit (disposed) into each of the through holes  31   ah  in the connector case  31   a . A portion (tip) of the elastic member  34   a  protrudes from the outer circumferential surface of the connector case  31   a . The diameter of an imaginary circle in contact with the tip of each of the elastic members  34   a , or the imaginary circle C 1   a  circumscribing each of the elastic members  34   a  is larger than the inner diameter of the housing  51  of the microphone stand  4  (the outer diameter of the connector-supporting hole  53 ). 
     The shape of the elastic member in the present invention is not limited to the present embodiment. That is, the elastic member may have a shape of a cylinder, for example. 
     Mounting to and Dismounting from Microphone Stand of Microphone ( 2 ) 
     Referring to  FIGS. 4 and 8 , mounting to and dismounting of the microphone  2  from the microphone stand  4  will now be described, focusing on the differences from the first embodiment. 
     The microphone  2  is mounted to the microphone stand  4  through insertion of the lower end portion of the connector case  31   a  into the connector-supporting hole  53  of the input connector  50 . 
     While the lower end portion of the connector case  31   a  is inserted in the connector-supporting hole  53 , the elastic members  34   a  fitted in the through holes  31   ah  of the connector case  31   a  are disposed near the upper face  512  of the housing  51 . That is, the lower side portion of the elastic member  34   a  is compressed by the housing  51  against the connector case  31   a . The upper side portion of the elastic member  34   a  is exposed from the connector-supporting hole  53 . 
     As the lower side portion of the elastic member  34   a  is compressed by the housing  51 , the connector case  31   a  is pressed toward the center of the connector case  31   a  in the radial direction by the lower side portion of the elastic member  34   a  at an equal angular interval (at the interval of 90 degrees in the present embodiment). As a result, the elastic member  34   a  regulates the movement of the connector case  31   a  in the radial direction (the horizontal direction in  FIG. 9 ). 
     As described above, the connector case  31   a  is fixed by the elastic members  34   a  at the upper end of the connector-supporting hole  53 , similar to the connector case  31  (see  FIG. 6 ) of the first embodiment. The connector case  31   a  is not movable in the radial direction of the connector case  31   a . The connector case  31   a  is fixed by the latch claw  541  and the latch groove  312  at the lower end of the connector-supporting hole  53 . The connector case  31   a  is not movable in the longitudinal direction (the vertical direction) of the connector case  31 . Even when a desk with the microphone stand  4  is placed thereon is shaken, the microphone  2  thus does not pendulum on the latch claw  541  as a pivot, for example. As a result, the electrical connections between the connector case  31   a  and the latch claw  541  and between the connector case  31   a  and the ground terminal  524  become stable. That is, the ground line for the microphone  2  becomes stable. 
     SUMMARY 
     In the microphone  2  according to the embodiment described above, the connector case  31   a  includes the through holes  31   ah  in which elastic members  34   a  are disposed instead of the groove  311  of the connector case  31  in the first embodiment. The microphone  2  in the present embodiment restrains the backlash relative to the microphone stand  4  and facilitates mounting to and dismounting from the microphone stand  4  of the microphone  2 , similar to the microphone  1  in the first embodiment. That is, the microphone according to the present invention restrains backlash relative to a microphone stand and facilitates mounting to and dismounting from a microphone stand of a microphone. 
     In the embodiments described above, the microphones  1  and  2  do not include the microphone stand  4 . Alternatively, a microphone according to the present invention may include a microphone stand. Thus, an exemplary microphone according to the present invention includes a microphone unit, an output connector configured to output sound signals from the microphone unit, a case accommodating the output connector, and a microphone stand having a connector-supporting hole.