Automatic transmission or recording or transmission and reception control system

A system to automatically control the changeover of recording and recording stop, or transmission and transmission stop, and being employed in the recording or transmitting device provided with a vibration pick-up type microphone for picking up bone-conducted voice sounds. The automatic changeover of recording and recording stop or transmission and transmission stop is attained by control signals corresponding to impact vibrations except voice signals uttered by a microphone wearer himself, transmitted through his bones and picked up by the microphone or another controlling microphone.

The present invention relates to an automatic control system for use in the 
transmitter, recorder and transmitting and receiving device, said devices 
using a vibration pick-up type microphone and said system being employed 
so as to automatically control the changeover of transmission and 
transmission stop, recording and recording stop or transmission and 
reception. More particularly, the present invention relates to an 
automatic control system for automatically controlling, without 
malfunction, the changeover of transmission and transmission stop, 
recording and recording stop, or transmission and reception, using as 
control signals impact vibrations except for bone-conducted voice signals. 
The vibration pick-up type microphone is well known to pick up 
bone-conducted voice signals (which will be hereinafter referred to as 
vibrations) transmitted to the external auditory canal wall, mastoid 
cells, forehead, throat and the like, and picked-up vibrations are applied 
as inputs to the conventional transmitting or recording device causing the 
device to perform wireless or wired transmission or recording. The 
conventional transmitting and receiving device is also well known to 
perform wireless or wired transmission and reception using the vibration 
pick-up type microphone and a speaker. 
The transmitting and receiving device and the like using this vibration 
pick-up type microphone are characterized in that the microphone picks up 
vibration sounds well but not air-conducted sounds, and therefore most 
suitable for use under extremely noisy circumstances. In addition, the 
microphone is used attaching to the external auditory canal or the like, 
so that both hands of microphone wearing person are left free to do 
anything he wants at the time of transmission or the like. 
As the technique of changing transmission to reception and vice versa in 
the wireless transmitting and receiving device such as the two-way radio 
to which is connected the vibration pick-up type microphone having the 
above-mentioned features and being combined with the speaker, are well 
known the press talk system using a manual switch and the voice controlled 
system capable of automatically attaining the changeover of transmission 
and reception responsive to outputs of microphone, that is, the automatic 
control system capable of automatically changing reception to transmission 
by talking voice signals and changing transmission to reception when no 
talking voice signal is present, using the voice controlled transmitter or 
the like. Further, the improved voice controlled system is also well known 
to automatically change transmission to reception and vice versa 
responsive to voice sounds by employing the voice frequency division 
system relative to outputs of speaker and microphone, and applying as 
inputs outputs of microphone to the voice controlled device. 
However, these prior arts have the following drawbacks. 
Firstly, the press talk system achieves the changeover of transmission and 
reception by the manual switch, so that at least one hand of the wearer is 
occupied in every changeover operation, thus making it impossible for the 
wearer to use his both hands at the time of transmission or reception. 
Secondly, the voice controlled system capable of automatically controlling 
the changeover of transmission and reception responsive to talking voice 
signals makes it possible for the wearer to use his both hands at the time 
of transmission or reception, but the following disadvantages are caused: 
(1) When the receiving speaker is arranged adjacent the microphone, outputs 
of speaker are received as inputs by the microphone, thus causing such a 
malfunction that the transmitting circuit is changed open even if no 
talking voice is present; 
(2) When used under highly noisy circumstances over 95 dB, for example, 
ambient noises are received as inputs by the microphone, thus causing such 
a malfunction that the transmitting circuit is changed open; 
(3) This system uses talking voice sounds of microphone wearer as control 
signals for the voice controlled device and is arranged to automatically 
change transmission to reception when no control signal output of talking 
voice sound is present, so that when the wearer pauses a moment to take a 
breath or to select words in the course of transmission, transmission is 
changed to reception because of lack of voice sound and a fear will be 
caused that the other who is receiving the transmission may misunderstand 
the temporal and unintended stop of transmission as a true one; 
(4) Since transmission is made possible only by the utterance of a voice 
sound, the first letter of a monosyllable uttered, for example, "K" of 
"Ka" is cut off and only the vowel "a" is transmitted, thus making obscure 
contents transmitted; and 
(5) Even when the transmitting person speaks to not the receiving person 
but one of neighbouring persons, the automatic controller is also operated 
to make transmission possible and contents of their speech are heard by 
the receiving person. Therefore, the microphone wearer (or the 
transmitting person) must put off the microphone when he wants to speak to 
not the receiving person but anyone of neighbouring persons. 
Thirdly, the improved voice controlled system employs the frequency 
division manner relative to outputs of speaker and microphone to thereby 
overcome the disadvantage cited in the above-mentioned item (1). Namely, 
in the case of this system in which the voice controlled device is 
operated by bone-conducted voice signals, signal inputs received by the 
speaker are passed through a high-pass filter, which allows voice signals 
in the band of 300-5,000 Hz to pass through, to thereby exclude received 
signals having frequencies lower than a specific frequency (300 Hz) and 
outputs of microphone (bone-conducted voice signal outputs) are passed 
through a low-pass filter so as to exclude components having frequencies 
higher than the specific frequency (300 Hz). Therefore, the voice 
controlled device is rendered operative only by outputs passed through the 
low-pass filter, thus enabling the disadvantage cited in the item (1) to 
be overcome. However, disadvantages cited in items (2)-(5) are left 
unsolved by this improved voice controlled system because bone-conducted 
voice signals generated by the speech of microphone wearer are used to 
control the changeover of transmission and reception in the system. 
In the device for transmitting outputs of vibration pick-up microphone, the 
press talk system for controlling the changeover of transmission stop has 
the same drawback as described above in the paragraph of this system 
associated with the changeover of transmission and reception, and voice 
controlled and improved voice controlled systems also leave unsolved 
disadvantages cited in items (2)-(5). In these cases the changeover of not 
transmission and reception but transmission and transmission stop is 
attained. 
In the device for recording outputs of vibration pick-up type microphone, 
prior arts of controlling the changeover of recording and recording stop 
also leave unsolved disadvantages cited in items (2)-(5). In these cases 
the changeover of neither transmission and reception nor transmission and 
transmission stop but recording and recording stop is attained. 
It is therefore an object of the present invention to provide a system for 
automatically controlling the changeover of transmission and reception and 
capable of eliminating all of disadvantages cited in items (1)-(5). 
Another object of the present invention is to provide a system for 
automatically controlling the changeover of transmission and transmission 
stop as well as recording and recording stop, and capable of eliminating 
all of disadvantages cited in items (2)-(5).

A system of the present invention will be now described to automatically 
control the changeover of transmission and transmission stop as well as 
recording and recording stop. FIG. 1 is a diagram showing a principle of 
system in which a main circuit for achieving transmission or recording is 
closed and opened responsive to control signals. FIG. 2 is a diagram 
showing another principle of system in which the main circuit, to which 
voice signals are applied as inputs, is rendered ON and OFF responsive to 
control signals. 
In Figures numeral 1 represents a vibration pick-up type microphone serving 
to pick up bone-conducted voice signals transmitted to the external 
auditory canal, mastoid cells, forehead, throat and the like, and convert 
voice signals to electrical ones to be applied as outputs. Numeral 2 
denotes a main circuit for allowing transmission or recording to be 
performed after outputs from the microphone 1 are amplified by an 
amplifier 3, and 4 represents an ON and OFF changeover circuit serving to 
open and close the main circuit 2 responsive to inputs of control signals. 
Said main circuit 2, amplifier 3 and changeover circuit 4 are ordinarily 
included in conventional transmitting or recording devices such as FM 
radio, wired transmitter or recorder. In FIG. 2 showing another principle 
of system, numeral 4A represents an ON and OFF changeover circuit (or 
switch) for allowing voice signals from the microphone 1 to be applied as 
inputs to the main circuit 2, that is, when the switch 4A is put ON, the 
main circuit 2 is opened while when OFF, the main circuit 2 is closed. 
A feature of the present invention is that impact vibration except voice 
signals uttered by the microphone wearer and picked up by the microphone 1 
through his bones are used as control signals for rendering the main 
circuit 2 opened and closed. Another feature of the present invention is 
that according to the order in which control signals are picked up by the 
microphone 1, for example, according to first and second control signals, 
the changeover of transmission and transmission stop or recording and 
recording stop is attained. Therefore, according to the present invention, 
outputs of microphone 1 are passed through a low-pass or band-pass filter 
5 such as a low-pass filter which allows outputs having frequencies, for 
example, lower than 200 Hz (preferably 130 Hz) to pass through, or a 
band-pass filter which allows outputs having frequencies, for example, in 
the band of 50-200 Hz (preferably 80-130 Hz) to pass through, and outputs 
passed through the filter 5 are applied as inputs to an automatic 
changeover controller 6, which changes the operation of changeover circuit 
4 or 4A. 
As described above, the low-pass or band-pass filter 5 is used to render 
the automatic changeover controller 6 operative only by control signals. 
However, another vibration pick-up type microphone 1A may be used to pick 
up control signals having frequencies lower than 200 Hz or in the band of 
50-200 Hz, and outputs of microphone 1A may be applied as inputs to the 
automatic changeover controller 6, as shown in FIG. 3. Namely, other 
feature of the present invention is that the vibration pick-up type 
microphone 1 or 1A is used as a means for picking up control signals. 
Impact vibrations which are employed as control signals in the present 
invention are generated, for instance, by closing his upper and lower jaws 
of microphone wearer so as to strike his lower teeth against upper ones. 
Impact vibrations generated like this are higher in level by about 20 dB 
as compared with bone-conducted voice signals generated by voice sounds of 
microphone wearer in the frequency band lower than 200 Hz. Therefore, no 
fear is caused that bone-conducted voice signals are picked up as control 
signals to render the automatic changeover controller 6 operative and that 
vibrations of external auditory canal wall or the like generated by 
ambient noises are picked up as control signals to render the automatic 
changeover controller 6 operative because vibrations by ambient noises are 
lower in level as compared with impact vibrations. Namely, the present 
invention makes it possible to easily attain this functional effect by 
using special qualities of filter 5 and vibration pick-up type microphone 
1A. 
FIG. 6 shows an embodiment of system for automatically controlling the 
changeover of transmission and reception according to the present 
invention and having the above-mentioned arrangement. 
In the embodiment shown in FIG. 6 an ear-microphone is used as the 
microphone 1 to pick up bone-conducted voice signals from the external 
auditory canal wall and a portable wireless transmitter such as FM radio 
is used as a transmitting device P1. The output terminal of microphone 1 
is connected to the microphone input terminal of transmitting device P1 
and the output terminal of automatic changeover controller 6 is connected 
to the switch input terminal of transmitting device P1. This embodies the 
principle of system shown in FIG. 1. 
In more detail, the ear-microphone 1 comprises a microphone body 1a, which 
is inserted into the external auditory canal of wearer and serves to 
transmit and receive bone-conducted voice signals contacting with the 
canal wall, said microphone body 1a being formed cylindrical so as to be 
easily inserted into the external auditory canal and made of metal such as 
aluminum or hard plastic material, a vibration pick-up element 1b such as 
piezoelement for acceleratingly vibrating responsive to the vibration of 
microphone body 1a and converting bone-conducted voice signals to 
electrical signals, a support member 1c for supporting the pick-up 
element, a member 1c' for cutting the peak of voice signals and being made 
of damper material such as rubber, positive and negative plates 1d and 1e 
for the pick-up element 1b, and a lead wire 1f. The portable transmitting 
device P1 includes an amplifier 3, main transmitting circuit 2, changeover 
circuit 4, power battery 11, antenna 12, power switch 13 and volume 
adjustor 14, and to the transmitting device P1 is further connected a 
controlling section C including a filter 5 and controller 6. 
The system of the present invention having the above-mentioned arrangement 
is operated as follows to automatically control the changeover of 
transmission and transmission stop. 
When the power switch 13 is put ON and the microphone wearer strikes 
"click" his lower teeth against upper ones to generate an impact vibration 
(which will be hereinafter referred to as the first control signal), the 
first control signal is picked up by the microphone 1 and applied as an 
input to the low-pass or band-pass filter 5 through the amplifier 3; the 
controller 6 is operated by the output sent and selected by the filter 5 
and the changeover circuit 4 is put ON to thereby render the main 
transmitting circuit 2 open. When the microphone wearer utters voice 
sounds this time, his voice sounds are picked up as bone-conducted voice 
signals and converted to electric signals by the microphone 1, amplified 
by the amplifier 3, and transmitted outside through the main transmitting 
circuit 2. 
When the microphone wearer wants to stop the transmission, he may again 
strike "click" his lower teeth against upper ones to generate another 
impact vibration (which will be hereinafter referred to as the second 
control signal). The second control signal serves, like the first control 
signal, to render the controller 6 operative to automatically return the 
changeover circuit 4 to OFF state, so that the main transmitting circuit 2 
is closed to keep the transmission stopped. Under this state the main 
transmitting circuit 2 is never opened even if the microphone wearer 
speaks to anyone of neighboring persons and how noisy the ambient 
circumstance is. In other words, the controller 6 is not rendered 
operative until the first or second control signal is applied as an input, 
and the main transmitting circuit 2 is kept open from the time when the 
first control signal has been applied to the time when the second cotrol 
signal is applied. 
When the microphone wearer wants to start the transmission again, he may 
"click" his lower and upper teeth to generate the first control signal. 
It is possible that the circuit kept under transmission-possible state at 
first is then changed to transmission stop state by the input of first 
control signal. 
Though the system of the present invention has been described to 
automatically control the changeover of transmission and transmission 
stop, it can be also used to automatically control the changeover of 
recording and recording stop. In this case a conventional recorder is used 
instead of transmitting device P1, said recorder having a main circuit 2 
for recording outputs of microphone and a changeover circuit 4 for opening 
and closing the main circuit 2. The changeover of recording and recording 
stop is automatically controlled by first and second control signals same 
as impact vibrations employed in the above-mentioned embodiment. 
The system of the present invention will be now described to automatically 
control the changeover of transmission and transmission stop. 
In FIGS. 4 and 5, symbol A represents a transmitting line and numerals 1 
through 5 denote same members as those employed in systems shown in FIGS. 
1 through 3 and 6 and intended to automatically control the changeover of 
transmission and transmission stop as well as recording and recording 
stop. Numeral 6' represents an automatic changeover controller, which 
performs substantially same operation as that of controller represented by 
numeral 6 but serves to automatically control the changeover of neither 
transmission and transmission stop nor recording and recording stop but 
transmission and reception. 
In FIGS. 4 and 5, symbol B represents a receiving line, which is combined 
with the transmitting line A to form a transmitting and receiving device 
P2. Numeral 7 denotes a main receiving circuit for receiving signals 
transmitted from outside, 8 an amplifier for amplifying electrical signal 
outputs from the main receiving circuit, 9 a changeover circuit, and 10 an 
air-conducted type speaker (including a sound pressure type earphone) for 
converting received electrical signals to sound waves or a bone-conducted 
type speaker for converting received electrical signals to mechanical 
vibrations to be bone-conducted. 
The automatic changeover controller 6' may be arranged to turn ON one of 
changeover circuits 9A and 9B while the other is kept OFF, as shown in 
FIG. 5, said changeover circuit 9A serving to put ON and OFF the input of 
voice signals from the microphone 1 to the main transmitting circuit 2, 
and said changeover circuit 9B serving to put ON and OFF the output of 
received signals to the speaker 10 of main receiving circuit 7. This is an 
embodiment corresponding to the principle of system shown in FIG. 2. As 
seen in FIG. 3, the vibration pick-up type microphone 1A may be used 
instead of filter 5 in the receiving line A. 
Typical examples of system combining the transmitting line A with the 
receiving line B are as follows: 
(a) A transmitting and receiving device in which the microphone 1 of 
transmitting line inserted into the external auditory canal of wearer is a 
vibration pick-up type ear-microphone (which will be hereinafter referred 
to as ear-mic) for picking up bone-conducted voice signals through the 
external auditory canal wall, and the ear-mic is housed in the 
air-conducted type speaker 10, as shown in FIG. 7; 
(b) A transmitting and receiving device in which the air-conducted type 
speaker is housed in or attached to a case attached to a headphone, 
helmet-like hat (which is represented by numeral 18 in FIG. 7), or frame 
of spectacles, or a behind-ear case (which is represented by numeral 15 in 
FIGS. 10 and 11) attached to behind the external ear, and received voice 
sounds are heard by the ear to which the ear-mic is attached, or by the 
other ear; 
(c) A transmitting and receiving device in which the speaker 10 cited in 
the above item (b) is a sound pressure type one, and outputs of speaker 10 
are introduced into the ear-mic 1 through a sound conducting tube 16 (made 
of, preferably, elastic material such as rubber and synthetic resin), as 
shown in FIGS. 10 and 11; 
(d) A transmitting and receiving device in which the external ear of wearer 
to which the ear-mic 1 is attached is covered by an ear-muff, in which the 
air-conducted or bone conducted type speaker 10 is housed and to which the 
ear-mic 1 is connected; 
(e) A transmitting and receiving device in which the ear-mic 1 and the 
speaker 10 are attached to a U-shaped band, which is worn on the head of 
wearer, or both ear-muffs in such a way that the ear-mic 1 is attached to 
one of ears and the air-conducted or bone-conducted type speaker 10 to the 
other; 
(f) A transmitting and receiving device in which the air-conducted type 
speaker 10 is housed in a portable wireless transmitting and receiving 
device and output sounds of speaker 10 are connected through the sound 
conducting tube 16 to the ear-mic, as shown in FIGS. 8 and 9; 
(g) A transmitting and receiving device in which the microphone of 
transmitting line is not ear-mic but of vibration pick-up type and fixedly 
attached by means of an attachment band and the like to mastoid cells, 
forehead or throat, and the speaker attached to the external ear is a 
sound pressure type earphone. 
In FIGS. 9 and 11, numeral 17 represents a sound conducting passage. 
The system of the present invention having one of above-mentioned 
arrangements is operated as follows to automatically control the 
changeover of transmission and reception. 
When the transmitting and receiving person (or ear-mic wearer) clicks his 
lower and upper teeth to generate the impact vibration (or first control 
signal), the first control signal is picked up by the microphone 1; the 
output of microphone 1 is amplified by the amplifier 3, selected by the 
low-pass or band-pass filter 5, and applied as an input to the controller 
6; so that the controller 6 is rendered operative to cause the changeover 
circuit 9 to automatically change reception to transmission. When the 
wearer utters voice sounds this time, bone-conducted voice signals 
generated by his voice sounds are picked up by the microphone 1 and 
transmitted outside in wireless or wired manner through the amplifier 3 
and the main transmitting circuit 2. The speaker 10 is kept not to 
generate outputs during this period, since the main receiving circuit 7 is 
held under closed state. 
When the wearer wants to perform reception, he may again click his lower 
and upper teeth to generate another impact vibration (or second control 
signal). This second control signal is applied as input to the microphone 
1 in same way as the first control signal was; the output of microphone 1 
is applied through the amplifier 3 to the filter 5; and the output of 
filter 5 is applied to the controller 6'; so that the changeover circuit 9 
is caused by the output of controller 6' to automatically change 
transmission to reception. The changeover circuit 9 is kept unchanged 
under this state even if the wearer speaks to anyone of neighboring 
persons or how noisy the ambient circumstance is. 
As the circuit 9, 9A or 9B employed in the present invention to 
automatically control the changeover of transmission and reception, are 
used a semi-conductor relay switch circuit and the like comprising 
combining a transistor changeover circuit, mechanical relay switch and 
transistor, and both of main transmitting and receiving circuits 2 and 7 
are never caused to open or close at the same time. 
It is also possible in the present invention that, usually kept under 
transmitting state, the circuit is changed to receiving state by the first 
control signal. 
As the automatic changeover controller 6 or 6' used in the present 
invention, may be employed a semi-conductor (LM 170 type, LM 270 type, LM 
370 type made by, for example, National Semiconductor Company) combined 
with a flip-flop circuit, said semiconductor being well known to be used 
in radio, audio device and television circuit. 
The microphone wearer knows whether the device is under transmission or 
transmission stop, or recording or recording stop, or transmission or 
reception by meters attached to the conventional transmitter, recorder or 
transmitting and receiving device. However, it is also possible for the 
wearer to know these states by lamps or the like. 
The automatic control system of the present invention having the 
above-mentioned arrangement and function to automatically control the 
changeover of transmission and transmission stop or recording and 
recording stop is capable of eliminating above-mentioned disadvantages 
(2)-(5) unavoidable in the case of conventional voice controlled systems. 
In addition, even if it is used under highly noisy circumstances of over 
95 dB in level, its main transmitting or recording circuit is not switched 
over to opened or closed state until one of control signals, or impact 
vibrations, is applied as input to the circuit, to thereby prevent 
malfunction. Therefore, the system of the present invention is most 
effective when used under highly noisy circumstances with both hands of 
wearer occupied with a hand-work. 
Further, the automatic control system of the present invention having the 
above-mentioned arrangement and function to automatically control the 
changeover of transmission and reception is capable of eliminating all of 
disadvantages (1)-(5) unavoidable in the case of conventional voice 
controlled systems, and most effective, like the automatic transmission or 
recording control system, when used under highly noisy circumstances with 
both hands of wearer occupied with a hand-work.