Signal transmission device and method

A signal transmitting apparatus which makes exchanging information when pouring a liquid possible. A container body 201 of a transmitter side container 20 holds an electrically conductive liquid 402. A display 306 for confirming data reception is attached to a container body 211 of a receiver side container 21. The container body 201 and the container body 211 are electrically connected at a predetermined impedance by the liquid 402. Because digital data is modulated by a carrier of approximately 10 MHz, an electromagnetic field is generated. In particular, a return line 404 due to an electromagnetic near field is generated, and communications from the transmitter side container 20 to the receiver side container 21 becomes possible.

TECHNICAL FIELD

The present invention relates to liquid containers which exchange information when receiving liquid.

BACKGROUND ART

Hitherto, a method using the human body as a transmission path and transmitting and receiving video signals by contact has been known (Japanese Unexamined Patent Application Publication No. 7-170215). In this method, a signal communications path is formed with the human body, which is an electrical conductor, as a main communications path and an electromagnetic near field as a return communications line.

The inventors of the present invention have further developed the foregoing technology and have conducted research so that information can be exchanged using ionizable liquid as the main communications line, resulting in the present invention.

DISCLOSURE OF INVENTION

In view of the foregoing circumstances, it is an object of the present invention to provide a technology for easily exchanging information using an ionic liquid or electrically conductive liquid.

According to the present invention, in order to achieve the foregoing objects, a signal transmitting apparatus includes a modulator for modulating an electrical signal; a first electrode connected to the modulator; means for bringing the first electrode into direct or electrostatic contact with an electrically conductive liquid; a second electrode for making direct or electrostatic contact using the liquid as a medium; and demodulation means connected to the second electrode. The signal propagates through the liquid.

With this arrangement, signals can be exchanged using a liquid as a transmission path.

The means for bringing the first electrode into direct or electrostatic contact with the electrically conductive liquid includes, for example, a liquid container, such as a cup, for receiving liquid or a liquid container, such as a tank, which is a liquid supply source. By providing such a liquid container with the first electrode, the liquid and the electrode can be directly or indirectly connected with each other.

The second electrode also comes into contact with the liquid. For example, the liquid container, such as a cup into which the liquid is poured, a cup for receiving the original liquid, or a tank which is a liquid supply source, is provided with an electrode.

Modulation and demodulation can be performed by employing various methods, such as a frequency modulation (frequency shift keying) method, an amplitude modulation (amplitude shift keying) method, a phase shift keying method, and an amplitude phase shift keying method.

In a more specific example, a first liquid container includes signal generating means; a modulator for modulating an electrical signal from the signal generating means; an electrode connected to the modulator; and a container body for supporting the electrode. A second liquid container includes a container body; an electrode supported by the container body; a demodulator for demodulating a modulated signal supplied to the electrode; and means for processing the demodulated electrical signal. A transmission path is formed when an electrically conductive liquid is poured from either container to the other, and an electrical signal is transmitted from one container to the other.

The foregoing aspects of the present invention and other aspects of the present invention are described in the claims and illustrated in detail using the following embodiments.

BEST MODES FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will now be described.

A first embodiment of the present invention will now be described. The first embodiment exchanges information when transferring a liquid from one container (for example, a cup) to another.FIG. 1shows a transmitter side container20and a receiver side container21. In this drawing, the transmitter side container20includes a container body201. The container body201includes an electrode104and a transmission circuit section10(seeFIG. 2). The transmission circuit section10and a battery (not shown) are encased in a bottom section202indicated by the dotted hatching. The receiver side container21includes a container body211. The container body211includes an electrode301, a display306, and a reception circuit section30. The reception circuit section30and a battery (not shown) are encased in a bottom section212indicated by the dotted hatching.

In this example, an ionizable liquid (which is not shown inFIG. 1; see liquid402inFIG. 4) is held in the container body201of the transmitter side container20. As described below, a signal transmission path is formed by pouring a liquid from the container body201to the other container body211, and information is thus exchanged.

FIG. 2shows the configuration of the transmission circuit section10of the transmitter side container20. In this drawing, the transmission circuit section10includes a processor (microprocessor)100, an FSK (frequency shift keying) modulator101, a low-pass filter102, and a buffer amplifier103. An output signal from the buffer amplifier103is applied to the electrode104. A digital signal generated by the processor100is modulated by the FSK modulator101using two carriers (for example, 10 MHz and 14 MHz). Of this signal, only the fundamental wave is amplified by the low-pass filter102using the buffer amplifier103. This output is connected to the electrode104. As described above, the transmission circuit section10is incorporated in, for example, the container20. The electrode104is attached to the bottom section202of the container body201.

FIG. 3shows the reception circuit section30of the receiver side container21. In this drawing, the reception circuit section30includes a pre-amplifier302, a band-pass filter303, an FSK demodulator304, a processor (microprocessor)305, and the like. An electrical signal supplied to the electrode301is amplified at the pre-amplifier302, band-limited at the band-pass filter303, restored to digital data at the FSK demodulator304, and is then supplied to the processor305. The processor305displays the received information on the display306. This display306is provided on a side surface of the receiver side container21, and can be viewed by a user.

FIG. 4shows signal transmission using the transmitter side container20and the receiver side container21. InFIG. 4, the container body201of the transmitter side container40holds an electrically conductive liquid402(something which contains ions within, such as water containing impurities, salt water., and beverages such as wine, whiskey, and beer. Needless to say, it may also be a normal conductor such as mercury). This liquid402is indicated by the cross hatching. The display306for data reception confirmation is attached to the container body211of the receiver side container21. In the state shown inFIG. 4, the container body201and the container body211are electrically connected by the liquid402with a predetermined impedance. Under the conditions shown inFIG. 4, even if electrically connected, the return line of the communication path is unclear, and it seems impossible to perform communications. However, in the present system, since the digital data is modulated by a carrier of approximately 10 MHz, an electromagnetic field is generated, and in particular, a return line404by an electromagnetic near field component is generated, and communications is made possible.

The electrode104(301) attached to the container body201(211) can be attached, as shown inFIG. 5(a), so as to be immersed directly in the liquid. As shown inFIG. 5(b), the electrode104(301) may also be provided so as to form a capacitor with the electrode104(301) and the container body201(211) of a dielectric material relative to the liquid402. Since the signal supplied to the electrode is an alternating signal of approximately 10 MHz or greater, if, for example, the capacitance of the capacitor can be set to be approximately 100 pF, the impedance becomes approximately 150 Ω, which is sufficiently low.

InFIG. 4, a case in which the liquid is poured from the transmitter side container20into the receiver side container21is shown. However, since a communications path is also formed when the liquid is poured from the receiver side container21into the transmitter side container20, transmission in the direction opposite to the flow of the liquid may be performed.

A second embodiment of the present invention will now be described. In the second embodiment, a container having both a transmitter function and a receiver function is used. The exterior appearance of the container of this embodiment is substantially the same as the transmitter side container20or the receiver side container21shown inFIG. 1. However, a display306is provided on a side surface of the container. Basically, the circuit configuration is one in which the circuit ofFIG. 2and the circuit ofFIG. 3are integrated by sharing a processor100. However, a tilt sensor600is provided. InFIG. 6, portions corresponding to those inFIG. 2orFIG. 3are given corresponding reference numerals.

The tilt sensor600detects whether or not the container is tilted. When the tilt is equal to or greater than a predetermined value, the container is set in transmission mode. Otherwise, the container is in reception mode. The amount of tilt is detected by the processor100, and hysterisis is provided for switching between transmission and reception. Therefore, a carrier used in FSK modulation may be shared (even in cases of plural containers), and the apparatus may be simplified. In contrast, because it is undesirable for the power source for its own transmission circuit to be operating in reception mode, switching is performed by switches601and602. Needless to say, it is also possible to simply switch the FSK modulator101and the FSK demodulator304without controlling the power source for the transmission/reception circuitry. In this embodiment, for purposes of power saving as well, the power source itself is switched. In the drawing, RXVcc is a power supply line to the reception side circuit, and TXVcc is a power supply line to the transmission side circuit.

Besides the method using the tilt sensor600as the sensor wherein transmission mode is entered when the container is tilted, methods for detecting the fact that the container is held by a person using a pressure sensor or a capacitance sensor (in practice, changes in frequency of an oscillation circuit in which capacitance and inductance are combined, or a voltage induced via capacitance) is detected are viable.

Alternatively, methods in which a micro switch attached to the bottom of the container, thus detecting the fact that the container is lifted, and alteration of transmission/reception modes using a mode alternating switch explicitly provided on the container are naturally possible as well.

A third embodiment of the present invention will now be described. In this embodiment, different frequencies are used for carriers of the transmission/reception circuitry, and a full duplex method is employed.FIG. 7shows this embodiment in its entirety. In this drawing, portions corresponding to those inFIGS. 2,3, or6are given corresponding reference numerals. InFIG. 7, frequencies f1and f2(for example, 10 MHz and 14 MHz) are used on the transmission side, and f3and f4(for example, 18 MHz and 22 MHz) are used on the reception side, and each is separated by a band-pass filter700or303. In this method, transmission/reception are distinguished from other containers by the frequency bands as shown below:

Even when full duplex communications is performed at the same time as pouring liquid from one container to another, a minimum of two types of containers (indicated by A and B) is sufficient (FIG. 8). However, in the present embodiment, simultaneously transferring a liquid from one or more containers (for example, pouring from802and801into802) is forbidden.

A fourth embodiment of the present invention will now be described. In this embodiment, information is exchanged when a liquid is poured from a liquid supply apparatus (tank or the like).FIG. 9shows this embodiment in its entirety. In this drawing, a liquid supply apparatus900includes means for performing information communications which uses a liquid as a medium, and means for supplying the liquid. The liquid supply apparatus900includes a faucet-cum-electrode901. A container902is a container comprising communications means similar to that of the receiver side container21shown inFIG. 3. In this embodiment, the liquid is supplied from the liquid supply apparatus900to a container. At the same time, data is simultaneously supplied to the container902. (However, since communications may be two-way as well, communications by handshake is naturally possible, and the detection of the data is not one way). In this embodiment, for example, the price of the liquid supplied through the faucet-cum-electrode901is charged to the container902. Therefore, when the container is returned, the account can be settled automatically via a network. Naturally, since the calculation means and memory means are included in the container, when poured a plurality of times, the total price can be stored by the container. Further, there may naturally be a plurality of faucet-cum-electrodes901. By assigning an ID to the liquid supply apparatus900and by supplying the ID information to the container902side, different processings for various types of liquids may be performed using a plurality of liquid supply apparatuses900.

A fifth embodiment of the present invention will now be described. This embodiment is one in which an analog signal is transmitted.FIG. 10shows this embodiment. In this drawing, signal transmission means1005including an FM modulator, a buffer amplifier and the like, and video playback means1006for supplying a video signal thereto are connected to a container1001. As the video playback means1006, for example, a portable DV videocassette player/recorder, a video camera, or a video recording/reproducing apparatus using a hard disk may be used.1001,1005, and1006may be integrated, or connected by wires. Alternatively, as described in Japanese Unexamined Patent Application Publication No. 7-170215, a transmission path may be formed via the human body. A container1002is a signal receiver side container, and a demodulator1003(including a pre-amplifier, a filter, and the like) is connected. A video signal monitor1004is connected to the output. When an appropriate liquid is poured from the container1001into the container1002in such a system, a video signal is transmitted for that period only, and is observed using the monitor1004. Needless to say, a video signal memory may be prepared on the memory1004side, and in the absence of a video signal, this memory may be read. In addition, instead of using video signals, using audio signals or video-audio signals at the same time are also possible (in this case, modulation band splitting is performed).

In analog signal transmission, instead of using FSK modulation, normal FM modulation is used.

INDUSTRIAL APPLICABILITY

As described above, according to the present invention, the following advantages are achieved:1. Transmission of electrical information using liquid, which hitherto has not been used for transmitting electrical signals, is made possible;2. A new method in which information is transferred with the transfer of liquid may be realized; and3. An information transmitter using liquid as a transmission path may be realized.