JP5377216B2 - Microphone output connector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely secure a stable ground path for a microphone case of a shield member arranged on a connector base, in order to prevent noise from being caused by an external electromagnetic wave. <P>SOLUTION: The connector base 11 includes a longitudinal hole 14 vertically crossing a screw storage hole 12 from a side of its upper surface 11a, and a nut plate 15 which has a female screw 15a and is engaged with a male screw for output connector fixation and conductive cloth 16 which has a through-hole 16a that the male screw penetrates and can elastically deform, are arranged in the vertical hole 14. As the female screw is rotated to be moved outward in a radial direction to fix the connector base 11 in the microphone case, the conductive cloth 16 is compressed by the nut plate 15 in the vertical hole 14 and a part which is thereby swelled is brought into tight contact with a shield layer of a printed wiring board arranged on the connector base 11. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an output connector of a microphone (especially a condenser microphone), and more particularly, to an output connector of a microphone having a configuration capable of preventing the entry of strong electromagnetic waves radiated from a mobile phone or the like into the microphone. Is.

  Since the output impedance of the microphone unit is extremely high, the condenser microphone includes an impedance converter that converts the output into a low impedance. An FET (field effect transistor) is usually used for the impedance converter.

  In many cases, a phantom power source is used as a power source for the condenser microphone, and an audio signal from the microphone unit is output via a balanced two-core shielded cable for the phantom power source.

  In order to connect this balanced two-core shielded cable, EIAJ-RC-5236 “Latch Lock Round Connector for Audio Equipment” is defined at the end of the microphone case (microphone grip in the case of a handheld microphone). A 3-pin type output connector is attached.

  That is, this output connector has a connector base formed in a disk shape from PBT (polybutadiene terephthalate) resin, etc., and has a first pin for grounding, a second pin on the signal hot side, and a third pin on the cold side of the signal. It is made through.

  Since the connector base is made of a synthetic resin material, for example, when a mobile phone is used in the vicinity of a microphone, the electromagnetic wave (external electromagnetic wave) enters the microphone from the connector base, and this is detected by an impedance converter. Doing so can cause annoying noise.

  Therefore, in order to prevent the generation of noise due to electromagnetic waves, Patent Document 1 discloses that the upper surface and the peripheral surface of the connector base are non-conductive with the second and third pins for signals and only with the first pin for grounding. It has been proposed to put a shield cover that is conducting and contact the shield cover with the inner surface of the microphone case.

  Further, in Patent Document 2, in addition to the structure of Patent Document 1, a printed wiring board including a shield layer made of a solid pattern of copper foil is disposed on the upper surface of the connector base (the surface covered with the shield cover). It has been proposed to electrically connect the shield layer to the shield cover via the first pin.

  According to this, since the shield cover is electrically connected to the microphone case that acts as a ground, the intrusion of external electromagnetic waves can be almost surely prevented, but the contact portion between the microphone case and the shield cover has a coating film such as sebum or the like. When the oxide layer is present, there is a problem that the electrical impedance of the ground path becomes high and the resistance to the external electromagnetic wave is not sufficient.

JP 2005-94575 A JP 2005-311752 A

  Accordingly, an object of the present invention is to reliably ensure a stable grounding path for a microphone case of a shield member disposed on a connector base.

In order to solve the above-described problems, the present invention provides a disk-shaped connector base made of an electrical insulating material fitted in a metal microphone case with a ground pin and a signal pin extending therethrough, and a shield on the lower surface. And a circuit board fixedly disposed on the upper surface side of the connector base, and a screw receiving hole is formed in the connector base along a radial direction from the peripheral surface thereof. A female screw whose mounting position is regulated and a male screw screwed into the female screw are housed in the screw housing hole, and has a smaller diameter than the male screw opened in the microphone case. The male screw is rotated to move outward in the radial direction, and the edge of the male screw is brought into pressure contact with the edge of the hole, whereby the connector base is fixed to the microphone case. The connector base is provided with a vertical hole that vertically traverses the screw storage hole from the upper surface side, and a nut plate that has the female screw and is screwed into the male screw in the vertical hole; An elastically deformable conductive member having a through-hole through which the male screw passes, and the conductive member is disposed as a center side of the connector base, and the male screw is rotated to move outward in the radial direction, As the connector base is fixed in the microphone case, the conductive member is compressed by the nut plate in the vertical hole, and the bulged part firmly contacts the shield layer of the circuit board. It is a feature.

  In the present invention, a conductive cloth is preferably employed for the conductive member.

  A shield cover is disposed on the upper surface side of the connector base so as to cover the circuit board and have a hem portion in contact with the inner surface of the microphone case. The shield cover is electrically connected to the shield layer via the ground pin. It is preferable that it is connected to.

  According to the present invention, a stable grounding path from the microphone case to the shield layer through the male screw, the nut plate, and the conductive member is obtained, and the shielding performance against external electromagnetic waves is further improved.

  In addition, on the upper surface side of the connector base, a shield cover that covers the circuit board and whose hem portion contacts the inner surface of the microphone case is disposed, and the shield cover is electrically connected to the shield layer through the ground pin. Accordingly, there are two grounding paths, and the reliability of the electromagnetic wave shield is further improved.

The longitudinal cross-sectional view which shows the output connector which concerns on embodiment of this invention. AA sectional view taken on the line AA of FIG. The principal part expansion perspective view of the said output connector. The principal part expanded sectional view in the state (state of FIG. 1) before fixation of the said output connector. The longitudinal cross-sectional view similar to FIG. 1 which shows the state which fixed the said output connector. The principal part expanded sectional view in the state (state of FIG. 5) after the said output connector is fixed.

  Next, embodiments of the present invention will be described with reference to the drawings (FIGS. 1 to 6), but the present invention is not limited thereto.

  As shown in FIGS. 1 and 2, the output connector 10 according to this embodiment is mounted in a cylindrical microphone case 1. The output connector 10 is connected to a phantom power source (both not shown) via a balanced two-core shielded cable.

  The microphone case 1 is made of a metal material such as a brass alloy, and is included in the grounding system of the condenser microphone by being connected to the shielded wire of the balanced two-core shielded cable.

  The output connector 10 includes a disk-shaped connector base 11 made of an electrical insulating material such as PBT (polybutadiene terephthalate) resin. The connector base 11 is provided with three pins, such as a first pin E for grounding, a second pin SH on the signal hot side, and a third pin SC on the cold side of the signal by, for example, press-fitting.

  The connector base 11 is provided with a screw storage hole 12 extending in the radial direction from the peripheral surface toward the center. The screw storage hole 12 has a male screw (screw) 13 for fixing. Is stored.

  The microphone case 1 has a hole 2 corresponding to the screw storage hole 12. The hole 2 is a hole for inserting a tool such as a screwdriver (not shown) and turning the male screw 13, and the inner diameter thereof is smaller than the outer diameter of the male screw 13.

  In this embodiment, a printed wiring board 20 is placed on the upper surface 11 a of the connector base 11. As shown in FIG. 4, a shield layer 20a made of a solid pattern of copper foil is formed on the lower surface of the printed wiring board 20 (the surface facing the upper surface 11a of the connector base 11).

  Although not shown, a capacitor element for preventing high-frequency intrusion and a Zener diode element for preventing circuit breakdown due to static electricity are mounted on the upper surface of the printed wiring board 20 (see the above-mentioned patent document for connection of these elements). 2).

  A shield cover 30 is further disposed on the upper surface 11 a of the connector base 11 so as to cover the printed wiring board 20.

  In the shield cover 30, the second pin SH for signal and the third pin SC are non-conductive, and only the first pin E for grounding is conductive by soldering. The first pin E is also electrically connected to the shield layer 20a of the printed wiring board 20. Signal second pin SH and third pin SC are not electrically connected to shield layer 20a.

  A skirt (skirt) 30a is formed on the periphery of the shield cover 30 to be fitted to a part of the peripheral surface of the connector base 11 so as to hold down the printed wiring board 20, and the skirt 30a is fixed when the output connector 10 is fixed. Strongly contacts the inner surface of the microphone case 1.

  With reference to FIG. 3, the connector base 11 is formed with a vertical hole 14 that vertically crosses the screw storage hole 12 from the upper surface 11a side. In this vertical hole 14, a metal nut plate 15 having a female screw 15a screwed with the male screw 13 and an elastically deformable conductive member 16 having a through hole 16a through which the male screw 13 passes are accommodated. The

  The nut plate 15 is preferably a square washer that does not rotate with the male screw 13 and is sized to be immersed in the vertical hole 14.

  In addition, a conductive cloth having both conductivity and elasticity formed into a square plate shape is preferably used for the conductive member 16. The conductive member 16 may be formed in a disk shape. An example of this type of conductive cloth is “Seiren's product number SUI-10-70X”.

  In the vertical hole 14, the conductive member 16 is on the center side (radially inner side) of the connector base 11, and the nut plate 15 is on the peripheral surface side (radially outer side) of the connector base 11. Hereinafter, the conductive member may be referred to as “conductive cloth”.

  The output connector 10 is fixed in the microphone case 1 as follows. First, the nut plate 15 and the conductive cloth 16 are accommodated in the vertical hole 14, the male screw 13 is screwed into the female screw 15 a of the nut plate 15, and the male screw 13 is rotated clockwise, for example, into the screw accommodating hole 12. It is assumed to be in a state of sinking.

  In this embodiment, when the male screw 13 is submerged in the screw storage hole 12, as shown in FIG. 4, the conductive cloth 16 is not loaded and is not in contact with the shield layer 20a. You may make it contact with the shield layer 20a also in a load state.

  Then, as shown in FIG. 1, the output connector 10 is fitted into the microphone case 1, the screw receiving hole 12 is opposed to the hole 2, and a screwdriver (not shown) is inserted through the hole 2, so that the male screw 13 is turned counterclockwise. Turn clockwise and move radially outward to abut the head side edge 13 a against the inner edge of the hole 1.

  This state is shown in FIG. 5, and when the male screw 13 is further turned counterclockwise, the entire connector base 11 is moved to the left side in FIG. Is pressed against the inner surface of the microphone case 1.

  Further, when the male screw 13 is further rotated counterclockwise with the edge 13a of the male screw 13 abutted against the inner edge of the hole 2, the nut plate 15 is relatively moved toward the connector base as shown in FIG. 11 radially inward (left side in FIG. 6).

  As a result, the conductive cloth 16 is compressed, and the peripheral edge of the conductive cloth 16 bulges toward the outside of the vertical hole 14 and is strongly pressed against the shield layer 20 a of the printed wiring board 20.

  Thus, according to this embodiment, in the state where the output connector 10 is fixed in the microphone case 1, the first grounding from the microphone case 1 to the shield cover 30 to the first pin for grounding to the shield layer 20a. In addition to the route (ground route), a stable second grounding route from the microphone case 1 → the male screw 13 → the nut plate 15 → the conductive cloth 16 → the shield layer 20a is secured, so that an external radiation radiated from a mobile phone or the like is secured. The shielding property against electromagnetic waves can be further improved.

  In order to further improve the reliability of the second grounding path, the edge 13a of the male screw 13 is tapered (inclined), and the edge 13a bites into the inner periphery of the hole 2 when the male screw 13 is tightened. The oxide film or coating film formed on the microphone case 1 may be destroyed.

DESCRIPTION OF SYMBOLS 1 Microphone case 2 Hole 10 Output connector 11 Connector base 12 Screw accommodation hole 13 Male screw 14 for fixation 14 Vertical hole 15 Nut board 15a Female screw 16 Conductive member (conductive cloth)
16a Through-hole 20 Printed wiring board 20a Shield layer 30 Shield cover 30a Bottom E 1st pin for grounding 2nd pin for SH signal Hot side 2nd pin SC side cold side 3rd pin for signal

Claims (3)

A disk-shaped connector base made of an electrically insulating material that fits in a metal microphone case with a ground pin and a signal pin penetrated, and an upper surface side of the connector base having a shield layer on the lower surface A screw storage hole is formed in the connector base along the radial direction from the peripheral surface, and the mounting position is within the screw storage hole. A regulated female screw and a male screw screwed into the female screw are housed, and the male screw is turned from a hole having a diameter smaller than that of the male screw opened in the microphone case. In the microphone output connector in which the connector base is fixed in the microphone case by moving outward and pressing the edge of the male screw against the edge of the hole,
The connector base is provided with a vertical hole vertically traversing the screw accommodation hole from the upper surface side, and in the vertical hole, a nut plate having the female screw and screwed with the male screw, An elastically deformable conductive member having a through-hole through which a male screw penetrates, and the conductive member is arranged as a center side of the connector base, and the male screw is rotated to move outward in the radial direction, and the connector Along with fixing the base in the microphone case, the conductive member is compressed by the nut plate in the vertical hole, and the bulged part firmly contacts the shield layer of the circuit board. Microphone output connector.
  The microphone output connector according to claim 1, wherein a conductive cloth is used as the conductive member.   A shield cover is disposed on the upper surface side of the connector base so as to cover the circuit board and have a hem portion in contact with the inner surface of the microphone case, and the shield cover is electrically connected to the shield layer via the ground pin. The microphone output connector according to claim 1, wherein the output connector is a microphone.

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