GB2366694A

GB2366694A - Voice-actuated transmit/receive switching

Info

Publication number: GB2366694A
Application number: GB0021322A
Authority: GB
Inventors: Yien Chen Wun
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-12-10
Filing date: 2000-08-30
Publication date: 2002-03-13
Also published as: FR2814904A1; DE29921758U1; GB0021322D0

Abstract

The external voice control mouthpieces for radio interphones on the market receive voice signal under an open state. Therefore, the background noise is completely accepted and causes incorrect reaction. This invention uses a skin touch-controlled piezoelectric microphone because this kind of microphones receive voice signals under a closed state and thus are not interfered by the background noise. Furthermore, the piezoelectric microphone used in the present invention has the advantage of high sound wave voltage output without consuming any electric current. With a exclusively designed low power consuming voice control circuit, which merely obtains the power supply from the tiny electric current of the external capacity mouthpiece of the interphone. It thus achieves the goals of no batteries and no extra power.

Description

2366694 EXTERNAL VOICE CONTROL MOUTHPIECE OF RADIO INTERPHONE

WITHOUT USING BATTERIES AND BACKGROUND NOISE INTERFERENCE

BACKGROUND OF THE INVENTION

Field of Invention

5 The present invention relates to a voice control mouthpiece of the radio interphone and, more particularly, to an external voice control mouthpiece of radio interphone without using batteries and background noise interference.

Related Art Usually, one needs to manually presses the speak switch P.T.T. to begin radio 10 interphone talking. It is necessary in many cases if the switch can be driven by a voice control circuit using the speaker's sound wave instead of manual operation. However, the radio interphones (handheld phones) of famous brands on the market do not have an extra output current on the external terminal (socket) for external circuit. And commercialized external voice control mouthpieces designed for these kinds of radio interphones require 15 batteries to provide power supply. However, products of voice control mouthpieces with batteries have the defects of circuit erosion, finite battery lifetime, and that the batteries need to be recharged or replaced. Furthermore, most of the places for using radio interphones are extremely noisy or environments with rapid motion. These products available on the market adopt air conduction open type microphones as the mouthpieces, 20 any background noise is accepted so that the voice control mouthpieces often have erratic reactions. In view of the above defects, the inventor, after many years of hard working and research, invented this external voice control mouthpiece of radio interphone without using batteries and background noise interference.

As described above, the operators in places such as aircraft, ships, vehicles, traffic 25 pointsmen, fire fighting, factories, and mechanical vehicles at construction sites need radio I interphones for communication. If a voice control mouthpiece is used instead of a touch control one, both hands of the operator can still operate normally and a lot of accident disasters can be prevented. Considering the external voice control mouthpieces of several radio interphones on the market, most of these products have two fatal defects. One is that 5 they use open type microphones as the mouthpieces, which receive all the background noise other than the user's voice and thus often have incorrect reaction. Nevertheless, the places that require voice control mouthpieces usually have large background noise or wind shear sounds (such as running vehicles); thus the defect lowers the practicability. The other defect is that in radio interphones without external output power terminals (this type of

10 handsets forms the majority), there must be batteries in the voice control mouthpieces as the power supply for the circuit. However, products with internal batteries are likely to have acid or alkaline gas or liquid to erode and corrupt the circuit. Furthermore, batteries have a certain lifetime, and one has to replace or recharge the batteries very often for uses. The inventor of this invention did a thorough research and came up with this external voice 15 control mouthpiece of radio interphone without using batteries and background noise interference.

SUMMARY OF THE INVENTION

20 Object The external voice control mouthpieces for radio interphones on the market receive voice signal under an open state. Therefore, the background noise is completely accepted and causes incorrect reaction. This invention uses a skin touch-controlled piezoelectric microphone because this kind of microphones receives voice signals under a closed state

25 and thus is not interfered by the background noise. Furthermore, the piezoelectric microphone used in the present invention has the advantage of high sound wave voltage output without consuming any electric current. With a exclusively designed low power

2 consuming voice control circuit, which merely obtains the power supply from the tiny electric current of the external capacity mouthpiece of the interphone. It thus achieves the goals of no batteries and no extra power.

Further scope of applicability of the present invention will become apparent from the

5 detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

10 BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given hereinbelow illustration only, and thus are not limitative of the present invention, and wherein:

Fig. I is a block diagram of the principles of this invention; and 15 Fig. 2 is a basic circuit of the present invention.

Fig. 3 shows a skin touch-controlled piezoelectric microphone according to U.S. Pat. No. 5,778,079.

DETAILED DESCRIPTION OF THE INVENTION

The product of this invention is analyzed hereinafter according to its two main 20 ftinctions and circuit structure, and is explained with the accompanying drawings.

One feature of the invention is that it does not need any battery. For radio interphones without output power supply terminals, the product of this invention obtains power supply from the external mouthpiece point A and distributes the current through distributor resistors Rl, R2, R3,... to each point in the voice control circuit that requires power.

3 (The following explanation takes Figures I and 2 as the reference diagrams.) The external mouthpiece point A of a usual radio interphone connects a load resistor RA to its inner power supply point Vcc. The original purpose is to supply an external capacitor microphone (mouthpiece) with a work current. When an external P.T.T. manual 5 switch is pressed, the signal from that point is taken out and amplified for modulating the carrier wave. The potential difference generated from this point is transmitted to a voltage difference switch circuit to start emitting radio signals.

If a resistor with resistance below a critical point to start emission is serially connected between point A and point E on the circuit, then radio signals can be emitted (the resistance 10 is different from machines to machines and ranges from 10ko to 220ko).

If the current is to be extracted from point A for the external voice control circuit, then the total resistor of the circuit can not be smaller than the resistor value of a critical point for starting emission. Taking a radio interphone on the market as an example, a resistor with an emission critical point below 82kQ is connected between points A and E for 15 emitting signals. Therefore, the total resistor of the external voice control mouthpiece circuit can not be smaller than 82kQ. For a safer circuit design, the total resistor value should take lOOkQ as a lower limit. If a IOOkQ resistor is connected between points A and E, the voltage drop between the two ends is measured to be 4.2V and the current flowing through this resistor is 42 g A. In other words, if one wants to obtain a current 20 from the external mouthpiece of this radio interphone for the use of the external voice control circuit, the current consumption should be below 42 g A.

As described in the previous paragraph, if a tiny current is to be obtained from point A for the use of the voice control circuit of the present invention, one has to design an extremely low power consumption circuit. In this circuit, each amplification device makes 25 the best to increase its serial load resistor value to lower the power consumption. However, the most important and necessary device in this voice control circuit is the 4 microphone. Yet most of the microphones on the market do not satisfy the necessary requirements of the product of this invention; namely, (1) low or no power consumption, (2) small volume, (3) large output signal, and (4) being able to separate background noise.

Based upon the above description, the inventor already invented a microphone that

5 satisfies all the requirements needed for this invention, namely, the skin touch-controlled piezoelectric microphone (the U.S. Pat. No. 5,778, 079). It is a perfect companion for the product of this invention. The functions and features of the skin touch-controlled piezoelectric microphone, shown in Fig. 3, are described as follows.

This microphone comprises two pieces of ceramic piezoelectric plates 5, 6. The 10 opposite two surfaces are plated with thin films of metal as the two electrodes. One of the surfaces is in contact with a metal plate 3 which has a conducting wire; the other surface is in contact with a signal metal conductor plate 7 which has a conducting wire. These two ceramic piezoelectric plates 5, 6 with extending conducting wires are put in circular containers 1, 2. The front side of the circular container is provided with a spring plate or a 15 spring 8 to hold the ceramic plate, while the backside of the container is provided with an extra space for accommodating a circuit board 4. The conducting wire extending from the electrode of the piezoelectric plate can be soldered thereon for a feedback wire 9 to output voice signals. Or circuit elements can be disposed thereon for signal amplification or impedance matching. When the top side of this microphone touches the resonance part of 20 human bodies when speaking, such as both sides of the throat, cheek, chest, etc, then voice signal voltage can be output via the microphone.

Since the above skin touch-controlled piezoelectric microphone completely takes advantage of the direct contact of a piezoelectric element with vibrating skin, instead of air conduction in usual microphones so that all background noise is accepted, thus this

25 invention can almost separate the background noise. This microphone is easy to wear and has an elastic ring or belt that ties to a proper position on the neck or cheek.

Moreover, the microphone uses piezoelectric elements as its material, which can obtain the maximal voice frequency output without any work current. So it provides the best condition and companion for the voice control circuit the function of without using batteries.

This microphone is an independent and practical device developed by the inventor of 5 the present invention. (It has received the patent rights for a new invention in some countries such as the U.S. and Taiwan.) It does not only provide the present invention a good element, but also can be used in other products. However, this is out of the purview of this specification and is not explained in detail.

The invention being thus described, it will be obvious that the same may be varied in 10 many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.

EMBODIMENT The circuit principle and operation are explained with Figures I and 2.

1. A point A on an external mouthpiece of a radio interphone is connected to a point A on a voice control circuit. This point A further connects to each point requiring currents in the circuit via distributor resistors Rl, R2, R3,... Capacitors are attached to filter out the wrinkle waves of the voice signal for the circuit to use.

2. The voice signals from a point C on a skin touch-controlled piezoelectric microphone 20 are separated into two streams, one going through a capacitor C I to an input point D on a voice output circuit, and being output to the microphone signal input point A on the radio interphone; the other going through a capacitor C2 to a point F on a voice control signal amplifier for amplified signal output to an input point G on a double positive voltage rectifier. The output from this rectifier is further sent to an input point H on a 25 voice control mouthpiece switch circuit to complete the task of voice control signal 6 sending.

3. The signal from a point B on an external earphone of the radio interphone to a point B on the voice control circuit is separated into two streams. One goes through J2 and point E and is input directly into the earphone. The other serially connects a resistor 5 R3 and a capacitor C3 and connects to a point L, and is then input into a point M of a negative double voltage rectifier for giving away the right to speak to the other partner.

The negative reversed voltage obtained from the output terminal N is input to a point H on the voice control switch circuit to intercept signal sending from the voice control circuit. The function of this circuit is to let the partner finish talking before starting 10 the voice control circuit so as to achieve the goal of giving away the right of speaking to the other partner. This circuit can also be manually switched on and off.

4. In addition to the above main circuits in the voice control circuit, the peripheral circuits and devices are explained in detail hereinafter:

a. Mic-I is a skin touch-controlled piezoelectric microphone, which is provided for the 15 radio interphone a noiseless voice control signal.

b. J I is an input terminal of the mouthpiece of the microphone, J2 is an output terminal of the earphone. A stereo headphone set can be used on points J I and J2.

c. VR- I is a variable resistor for the sensitivity of the voice control signal sending. It can be replaced by a discrete switch to change among different resistor values.

20 d. S-1 is a time extension circuit for voice control. It can be replaced by a variable resistor too.

e. S-2 is a manually controlled mouthpiece switch. If the voice control circuit is to be controlled manually, the sensitivity of voice control signal sending has to be adjusted to the lowest level.

25 f. S-3 is a switch that controls whether the right of speaking is given away to the other 7 partner.

g. A voice output impedance circuit connects to the voice control switch circuit in series so as to achieve the goal of saving power consumption (points K and 1).

Only a minority of machines have a lower internal resistance and have to be 5 connected in parallel. The area enclosed by the dashed line in Fig. 2 is a terminal for the convenience of connection in series or parallel. There are also a few machines that have independent powers on the external terminals connecting to point A 1, e.g. the b area enclosed by the dashed line.

To minimize the voice control, the first voice amplifier in c area can be moved onto the 10circuit board of the skin touch-controlled piezoelectric microphone 8

Claims

What is claimed is:

1. An external voice control mouthpiece of radio interphone without using batteries and background noise interference, which comprises the features of- 5 without using batteries; wherein the voice control mouthpiece of the present invention does not require any type of batteries for radio interphones with or without external power supply terminals, for radio interphones with external power supply terminals the power of the voice control circuit being obtained from the terminal, for those without terminals the power supply being obtained from an external capacitor 10 microphone using a distributor resistor; the present invention uses a skin touch-controlled piezoelectric microphone, which is made of a piezoelectric element and can output a higher voice signal voltage than usual microphones without using any work current, to achieve, with the accompanying low power consumption voice control circuit, the function of without using batteries; and 15 without background noise interference; wherein the skin touch- controlled piezoelectric microphone receives voice signal in a closed state and thus can effectively avoid background noise; therefore, the product of the present invention utilizes the least devices to achieve the highest efficiency of the desired features.

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