JP2005039531A - Microphone - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a USB-supporting digital microphone usable as a duet microphone by connecting a usual analog microphone to the digital microphone. <P>SOLUTION: A USB interface 20 in a microphone A converts analog voice signals outputted from a microphone capsule 10 to digital voice signals to output the signals from a USB connector 30. The USB interface 20 includes a mixing amplifier 21 in its input stage and comprises an input jack 40 for connecting a usual analog microphone B, and the microphone capsule 10 and the input jack 40 are connected to the mixing amplifier 21 to make the microphones A, B usable at the same time. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a microphone connected to a digital device such as a personal computer via a USB connector, and more particularly to a duet microphone that can be connected to another microphone.

  Microphones include a capacitor type and a dynamic type. In any case, an analog audio signal is output from the microphone capsule. Therefore, when a microphone is used by being connected to a digital device such as a personal computer or a game machine, it is necessary to convert an analog audio signal into a digital audio signal.

  In recent years, USB (Universal Serial Bus: see Non-patent Document 1 below) that can automatically recognize a peripheral device connected to the personal computer by plug and play is used as an interface for connecting the personal computer and the peripheral device. It has been.

  For this reason, a USB-compatible microphone (hereinafter sometimes simply referred to as a USB microphone) is equipped with a USB interface having an A / D conversion function, and a USB connector instead of a single-head plug is provided at its output terminal. Used.

  By the way, for example, when karaoke software is installed on a personal computer or game machine to perform a duet, conventionally, two USB microphones are used and each USB connector is connected to a USB input port on the personal computer or game machine side. However, this has the following problems.

  That is, generally, only about two USB input ports are provided in a personal computer, a game machine, and the like, and when performing a duet, the USB input port is occupied by two USB microphones.

Therefore, if there is an already connected device, it must be removed and a USB microphone must be connected. If the already connected device cannot be removed, it is necessary to prepare a USB hub for expansion separately. In addition, as a problem before that, a USB microphone is more expensive than a normal analog microphone, so it is costly to prepare two USB microphones for a duet.
Published by Ohm Co., Ltd., electronic magazine "Electronics" May 1998 (p.31-43)

  Therefore, the problem of the present invention is that when two microphones are connected to a digital device such as a personal computer or a game machine and used at the same time, only one USB-compatible microphone is required, and other microphones are usually inexpensive. It is to be able to use a simple analog microphone.

  In order to solve the above problems, the present invention provides a USB interface having a microphone capsule that converts a sound wave into an analog audio signal, and an A / D converter that converts the analog audio signal output from the microphone capsule into a digital audio signal, and A microphone including a USB connector as an output terminal and connected to a digital device having audio output means via the USB connector, the mixing amplifier connected to the previous stage of the A / D converter, and another microphone are provided And an input jack into which an output plug for analog audio signal output is inserted, and the microphone capsule of the own device and the input jack are connected to the input stage of the mixing amplifier.

  The mixing amplifier may be externally attached to the USB interface. However, from the viewpoint of assembling workability, the mixing amplifier is preferably built in the USB interface together with the A / D converter.

  The microphone of the present invention includes various types of microphones such as a hand microphone and a stand microphone. In the case of a hand microphone, the input jack is preferably provided in the cord bush portion of the grip end. As another aspect, the input jack may be drawn out of the grip through a cable penetrating the cord bush portion of the grip end. As the input jack, a monaural jack having an inner diameter of 3.5 mm or 6.3 mm is preferably employed.

  The microphone of the present invention is a USB microphone. By connecting an analog microphone to the input jack, analog audio signals output from the respective microphone capsules are mixed and A / D converted by a mixing amplifier. It is given to a digital device such as a personal computer or a game machine from one USB connector. Therefore, for example, when performing a duet, both need not be USB microphones, and one of them may be an inexpensive analog microphone. Further, it is not necessary to use two USB input ports on the digital device side.

  Next, an embodiment of the present invention will be described with reference to FIGS. 1 and 2, but the present invention is not limited to this. FIG. 1 is a schematic diagram showing a circuit configuration of a microphone according to the present invention, and FIG.

  A microphone (parent microphone) A of the present invention includes, as basic components, a microphone capsule 10 that converts an incoming sound wave into an analog audio signal, and a USB interface 20 that converts the analog audio signal into a USB-compatible digital audio signal. A USB connector 30 as an output terminal and an input jack 40 for connecting another microphone (child microphone) B are provided.

  The microphone capsule 10 may be either a capacitor type (electrostatic type) or a dynamic type (conductive type), but in the case of a vocal microphone, the dynamic type is preferable from the viewpoint of sound quality. The child microphone B includes a similar microphone capsule. However, in the case of the child microphone B, the analog audio signal is output as it is from the single-head plug P as an output terminal.

  The USB interface 20 includes a mixing amplifier 21 as an input unit and an A / D converter 22 connected to the output stage of the mixing amplifier 21. In this example, a mixing amplifier built-in type IC chip is used for the USB interface 20, and this type of IC chip is, for example, AK5370 (product number) manufactured by Asahi Kasei Corporation. If the mixing amplifier is not built-in, a mixing amplifier may be externally attached in front of the input unit.

  A microphone capsule 10 and an input jack 40 are connected to the input side of the mixing amplifier 21. That is, the mixing amplifier 21 mixes the analog audio signal from the microphone capsule 10 of the parent microphone A that is its own device and the analog audio signal of the child microphone B input from the input jack 40.

  In this example, a talk switch 11 that turns on and off an analog audio signal is connected between the microphone capsule 10 and the mixing amplifier 21. In the present invention, the talk switch 11 is an optional component, but in some cases, a talk switch may be provided between the input jack 40 and the mixing amplifier 21.

  The A / D converter 22 converts the analog audio signal output from the mixing amplifier 21 into a USB-compatible digital audio signal. Although not shown in detail, the USB connector 30 includes a pair of data lines D + and D− and a power supply line VD and a GND line. The A / D converter 22 is connected to the USB connector via a noise removal filter 31. It is connected to 30 data lines D + and D-.

  In the present invention, the noise removal filter 31 is an optional component. In this example, the USB interface 20 obtains, for example, +3.3 V as an operation power source from the USB power line VD (+5 V) via the voltage regulator 32.

  As the input jack 40, either a monaural type or a stereo type is selected according to the specification of the single-head plug P provided in the child microphone B. When the parent microphone A is a hand microphone having the substantially cylindrical grip 50 shown in FIG. 2, the USB interface 20 and the noise removal filter 31 are accommodated in the grip 50, and the USB connector 30 blocks the grip end. For example, it is pulled out of the grip through the USB cable 33 penetrating the rubber cord bush portion 51. According to a preferred embodiment of the present invention, the input jack 40 is provided in the cord bush portion 51 as shown in FIG. .

  Since the cord bush portion 51 is limited in size (diameter) in design, it is preferable to use a mini monaural jack with an inner diameter (φ) of 3.5 mm as the input jack 40. If possible, a φ6.3 mm monaural jack or a stereo type input jack can be used.

  As another aspect of the present invention, the input jack 40 may be pulled out of the grip 50 via a cable (not shown) that passes through the cord bush portion 51. Further, depending on the design method, the input jack 40 can be provided at a predetermined middle portion of the USB cable 33 for pulling out the USB connector 30. Furthermore, depending on the specifications of the mixing amplifier 21, a plurality of input jacks 40 can be provided.

  Next, an example of using the parent microphone A together with the child microphone B for a duet will be described. First, the USB connector 30 of the parent microphone A is plugged into (connected to) a USB input port of a game machine which is a digital device having a sound output means (not shown).

  In this state, the analog audio signal of only the parent microphone A is converted into a digital signal by the A / D converter 22 and given to the game machine via the USB connector 30. When the child microphone B is used as a duet microphone, the single-head plug P is inserted into the input jack 40.

  Thereby, the analog audio signal of the parent microphone A and the analog audio signal of the child microphone B are mixed by the mixing amplifier 21, converted into a digital audio signal by the A / D converter 22, and output from the USB connector 30. If the talk switch 11 of the parent microphone A is turned off, only the audio signal from the child microphone B is given to the game machine.

The schematic diagram which shows the circuit structure of the microphone by this invention. 1 is an external view of a main part of a microphone according to the present invention.

Explanation of symbols

10 Microphone capsule 11 Talk switch 20 USB interface 21 Mixing amplifier 22 A / D converter 30 USB connector 33 USB cable 40 Input jack 50 Grip 51 Cord bush part A Microphone (parent)
B Microphone (child)

Claims (5)

A microphone capsule that converts sound waves into an analog audio signal, a USB interface having an A / D converter that converts the analog audio signal output from the microphone capsule into a digital audio signal, and a USB connector as an output terminal, In a microphone connected to a digital device having audio output means via a USB connector,
A mixing amplifier connected to the front stage of the A / D converter; and an input jack into which an output plug for analog audio signal output included in another microphone is inserted; Is connected to the input stage of the mixing amplifier.   The microphone according to claim 1, wherein the mixing amplifier is built in the USB interface together with the A / D converter.   The microphone according to claim 1 or 2, wherein the microphone is a hand microphone having a grip, and the input jack is provided in a cord bush portion of a grip end.   4. The microphone according to claim 1, wherein the microphone is a hand microphone having a grip, and the input jack is drawn out of the grip through a cable penetrating a cord bush portion of a grip end.   The microphone according to any one of claims 1 to 4, wherein a monaural jack having an inner diameter of 3.5 mm or 6.3 mm is used as the input jack.

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