JP2001156724A - Data communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a data communication system that can increase the communication speed without limiting applications of communication and accurately identify the transmission signal. SOLUTION: In the data communication system provided with a data transmitter 1 that pulse-modulates or amplitude-modulates a carrier with data going to be transmitted and provides the output of a modulated signal from a part attached to a human body and with a data receiver 2 that receives the modulated signal outputted from the data transmitter 1 when the human body with the data transmitter 1 attached thereto contacts the receiver 2 to demodulate the modulated signal, the data receiver 2 is provided with a rectifier section 10 that rectifies the modulated signal to demodulate the modulated signal, with a DC component attenuation section 11 that eliminates a DC component of the signal rectified by the rectifier section 10 and with a signal level attenuation section 12 that attenuates the signal rectified by the rectifier section 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data receiving apparatus of a data communication system for transmitting and receiving data, and more particularly to a data communication system for transmitting and receiving data using a human body as a transmission line.

2. Description of the Related Art Conventionally, as a method of data communication between a data transmission device carried by a person and a data reception device installed near the same, a method using wired communication by cable connection, a method using light, radio waves, or the like. There is a method using wireless communication. When data is transmitted from a data transmitting device to a data receiving device, in a method using wired communication, the device itself can be configured to be relatively inexpensive and small.
However, it is necessary to connect the data transmitting device and the data receiving device with a cable before starting data transmission / reception, or to disconnect the cable after the data transmission / reception is completed, which is not always convenient for the user. There was a problem that it was not something. On the other hand, in the method using wireless communication, the operation of connecting a cable is not required, so that data communication can be easily performed. However, the problem is that the data communication device is expensive and large. Had a point. As means for solving such conventional problems, for example, JP-A-10-228524 and JP-A-10-2293 are known.
There is one described in JP-A-57-57. In these devices, a data communication device that transmits data from a data transmission device attached to a human body to a data reception device using the human body as a transmission path has been proposed. It is possible to use a device that is inexpensive and small in size, and it is possible to easily transmit and receive data because there is no need to connect a cable or the like. By the way, when an amplitude modulation method or a modulation method using a pulse as a carrier is used, the high and low of the waveform are used in order to finally identify the data.
It is necessary to distinguish w. As a countermeasure, if the DC component of the signal rectified in the data receiving device is deleted and a method of discriminating the high and low of the signal waveform based on the reference value (so-called ground) is used, the level fluctuation of the rectified waveform can be achieved. Since the reference value fluctuates automatically with the addition of noise, it is possible to effectively distinguish between High and Low of the waveform. On the other hand, when increasing the data communication speed in a general communication method, the amount of data per unit time must be increased. For this purpose, there are measures such as increasing the carrier frequency. However, considering hardware restrictions, it is most effective to transmit one piece of information with, for example, one bit of digital data. When the data communication speed is increased by the above-described measures, the data communication device using a human body as a transmission path has the following problems. That is, 1) Since rectification is generally performed using the charge / discharge characteristics of a capacitor, if the charge characteristics are improved in order to increase the rectification effect, the discharge characteristics deteriorate, and as a result, the data length becomes longer than the original data length. 2) Since one bit has one piece of information, when the same information is continuous, that is, when the signal level is considered, if the states of High and Low continue, the state becomes the same as the DC component. Is deleted, the information of the original waveform is lost. In order to solve these problems, with respect to the above 1), the data transmission device and the data reception device synchronize the data and forcibly discharge the data when the high state of the data ends, thereby discharging the capacitor. There are measures such as deleting specifics. For the above 2), change the protocol.
That is, there is a method in which one piece of information is always combined with a signal level of High or Low, or a method of restricting information, that is, a method of not using an information form in which a signal level of High or Low continues.

However, in the above-mentioned data communication system using a human body as a transmission line, in a system for synchronizing data communication between a data transmitting device and a data receiving device, both devices are used. Since the communication system must always be in the same area and have an environment in which communication for synchronization can be performed, there is a problem that the use of the communication system is limited. Also, one piece of information must be at the signal level Hi.
The method using the combination of gh and Low has a problem in that the protocol for transmitting one piece of information is changed in order to increase the communication speed, so that the original purpose is not satisfied. In addition, signal level High,
In a method of not using an information form in which Low continues, for example, the amount of information is limited, which also has a problem that its use is limited. The present invention has been made in view of the above problems, and aims to increase the communication speed without limiting the use of communication,
Another object of the present invention is to provide a data communication system capable of accurately identifying a transmission signal.

According to the first aspect of the present invention,
A data transmission device that performs amplitude modulation or modulation using a pulse as a carrier wave based on data to be transmitted and outputs a modulation signal from a portion attached to the human body, and a human body having the data transmission device attached thereto. A data receiving device for receiving a modulated signal output from the data transmitting device and demodulating the modulated signal, wherein the data receiving device rectifies a signal to demodulate the modulated signal. A rectifying unit, a DC component attenuating unit that removes a DC component of the signal rectified by the rectifying unit, and a signal level attenuating unit that attenuates the signal rectified by the rectifying unit at a predetermined cycle. It is characterized by the following. The invention described in claim 2 is claim 1
5. The data communication system according to claim 1, wherein the data receiving device includes an arithmetic processing unit that performs arithmetic processing on the demodulated data, and reads data in the arithmetic processing unit and attenuates a signal level of the data in the signal level attenuation unit. Are linked to each other. According to a third aspect of the present invention, in the data communication system according to the second aspect, the signal level attenuating section has an attenuation time adjusting section for adjusting an attenuation time, and the arithmetic processing section sends a control signal based on a result of the arithmetic processing. A control signal output section for outputting the signal level, and an attenuation time of the signal level attenuation section is adjusted based on a control signal from the control signal output section. The invention according to claim 4 is
4. The data communication system according to claim 3, wherein the DC component attenuator includes an attenuation amount adjuster that adjusts an amount of signal attenuation, and the amount of attenuation of the DC component attenuator is adjusted by a control signal from the control signal output unit. It is characterized by doing so. According to a fifth aspect of the present invention, in the data communication system according to any one of the first to fourth aspects, the data receiving device includes a minimum value detecting unit, and the signal level attenuating unit adjusts an attenuation level of the signal. An adjustment unit is provided, and the attenuation level of the signal level attenuation unit is adjusted by a control signal from the control signal output unit. The invention according to claim 6 is
6. The data communication system according to claim 1, wherein said data transmission device adds additional data for distinguishing data to data when performing modulation based on data to be transmitted. Is provided. According to a seventh aspect of the present invention, in the data communication system according to the sixth aspect, the additional data attachment unit prevents a signal of a high level or a low level from being continuously generated for a predetermined time. It is assumed that. According to an eighth aspect of the present invention, in the data communication system according to the sixth or seventh aspect, the additional data appending unit is configured to generate a high-level signal more frequently than a low-level signal. It is a feature.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a data receiving apparatus of a data communication system according to an embodiment of the present invention will be described in detail with reference to FIGS. FIG. 1 is a schematic diagram of a data communication system using a human body 3 as a transmission path. The signal 4 is transmitted from the data transmitting device 1 via the human body 3 to the data receiving device 2
Has been transmitted. Here, the data transmitting apparatus 1 generates a signal and transmits the signal to the human body 3, and a transmission signal modulated based on data to be transmitted is applied to the human body. As its configuration, for example, two electrodes arranged so as to face a human body, an oscillating unit that generates an AC signal, and modulates the AC signal based on data to be transmitted to output a modulated signal Some include a modulation unit and a voltage application unit that applies a voltage corresponding to the modulation signal between the two electrodes. The data transmission device 1
In FIG. 1, it is worn on the arm, but the installation place is not particularly limited. Also, the data receiving device 2
Also, in FIG. 1, it exists outside the human body 3,
Like the data transmission device 1, it may be mounted on the human body 3, and the installation place is not limited. Note that the signal 4 is a composite signal obtained by adding a human body signal to the modulation signal. FIG. 2 shows a part of the configuration of the data receiving device 2. When the signal 4 is input to the data receiving device 2, the signal 4 is input to a rectifier 10 for demodulating a modulated signal via a filter, an amplifier, and the like. The signal input to the rectifier 10 is rectified in a form close to the original data signal. The rectified signal is input to the DC component attenuator 11, and the DC component of the signal is deleted. FIG. 3A shows a DC component attenuator 11.
3B shows the waveform before the input in the DC component attenuator 11. As a result, it is possible to distinguish between High and Low of the input waveform depending on whether the level is higher or lower than the ground level. FIG. 4 (a)
4 shows a signal before information is given by the signal level, and FIG. 4B shows a signal after information is given by the signal level. In the method of giving one information by one bit, information of data “0” is assigned by a 1-bit low level signal, and information of data “1” is assigned by a 1-bit high level signal. (See FIG. 4A). In addition, in the case where one piece of information is always combined with a combination of High and Low, information of data “0” is assigned with a total of 2 bits of Low + High, and a total of 2 bits of Low + High + High is assigned.
Information of data "1" is assigned by bits (see FIG. 4B). In other words, the latter requires 2.5 times the number of bits when expressing the same information of data “01” with respect to the former approach. That is, in the latter case, if the time per bit does not change, the amount of information per unit time decreases, that is, the transmission speed decreases in data communication. FIG.
A waveform when data “1” is continuously input to the data receiving device 2 using a method of giving one piece of information using bits is shown, and (a) shows a waveform before input in the DC component attenuator 11. (B) shows the waveform after the input in the DC component attenuator 11. The state in which the data “1” continues is a state in which the High level continues in the signal level. That is,
In this state, since there is no switching between High and Low, it is not an AC state in which the level changes but a DC state in which the level is constant, and when the DC component is deleted by the DC component attenuating unit 11, the signal becomes The level is the ground level,
That is, the waveform becomes equal to the Low level, and it becomes impossible to identify the waveform when the signal level is higher or lower than the ground level. FIG. 6 shows a data receiving device 2 according to the present embodiment. FIG. 7 shows a waveform when data “1” is continuously input to the data receiving device 2 in the data receiving device 2 according to the present embodiment, and FIG. (B) shows the DC component attenuating unit 11
3 shows the waveform after input. Data "1", that is, Hi
The gh level signal is periodically attenuated to the ground level by the signal level attenuator 12. As a method of attenuating, for example, a discharge or the like by conduction with the ground is used. When the decay is stopped, the signal level becomes the high level again due to the specific charge of the rectifier 10. The state where these are repeated is the waveform shown in FIG. When this waveform is input to the DC component attenuator 11, unlike the case where the signal level is not attenuated by the signal level attenuator 12, the signal levels are set to High and Low.
In other words, since there is a change in the AC component, that is, the waveform does not go all the Low level even after the DC component is deleted, and as shown in FIG. Will exist. As a result, even in a state where data “1”, that is, a high level signal is continuous, it is possible to accurately identify data based on the ground level. FIG.
Is an arithmetic processing unit 20 in the configuration of the receiving apparatus 2 shown in FIG.
A wiring for cooperating with the signal level attenuating unit 12 is added. FIG. 9 shows a waveform when data “1” is continuously input to the data receiving apparatus 2 in the data receiving apparatus 2 according to the present embodiment, and FIG. (B) shows the waveform after the input in the DC component attenuator 11. In FIG. 9, arrows indicate data reading points by the arithmetic processing unit 20, and reading is performed at regular time intervals. In FIG. 9, the time for attenuating the signal level is longer than that in FIG. 7, which is considerably different from the original waveform in which the High level continues. However, since the data is read at the same High level as the original signal waveform, the arithmetic processing unit 20 can determine that the same data is being processed. This is the arithmetic processing unit 20
This is because the data and the signal level attenuating unit 12 cooperate with each other so that data is not read when the signal is attenuated. As shown in FIG. 9, the longer the attenuation time, the shorter the High level time, that is, Hi
Since the DC component of the gh level is reduced, the DC component deleted by the DC component attenuator 11 is reduced as a result, and the High and Low levels with respect to the ground level are increased. Therefore, by cooperating, it is possible to control the waveform after the input of the DC component attenuating unit 11 without affecting the arithmetic processing unit 20, that is, affecting the accurate identification of data. . That is, when the human body signal is small, the decay time is reduced, and as shown in FIG. 7, the center level of the waveform is set below ground, and when the human body signal is small, the decay time is lengthened, and as shown in FIG. It is possible to adjust the level so that it is above ground. FIG. 10 shows a configuration of the data receiving device 2 shown in FIG.
And a control signal output unit 21. If the information has a large number of data "1" components, the entire information has a large DC component, and if the decay time is short, the signal component is below the ground level as shown in FIG. If the signal level fluctuates due to noise or the like in this state, the signal of data “1” becomes lower than the ground level, and there is a possibility that the signal is identified as data “0”. If the information has a large amount of data "0" components, on the contrary, since the DC component is small, if the decay time is long, the signal components are high above the ground level as shown in FIG.
Due to the change in the signal level, there is a possibility that data “0” is identified as data “1”. Therefore, while the data is being processed by the processing unit 20, the occurrence ratio between the data "1" and the data "0" is calculated, and the control signal output unit 21
The decay time adjustment unit 1 uses the calculation result as a control signal
3 to adjust the decay time so that the ratio of the signal waveform to the ground level is equal to the top and bottom as shown in FIG. It is possible to reduce it. FIG. 11 is obtained by adding a minimum value detecting unit 31 and an attenuation level adjusting unit 14 to the configuration of the data receiving device 2 shown in FIG. FIG. 12 shows waveforms before and after the signal level attenuating unit 12 attenuates and waveforms after the input of the DC component attenuating unit 11 in the configuration of FIG. When a noise component is added to the low-level signal shown in FIG.
As shown in FIG. 12B, after the signal level is attenuated, the waveform has a noise level upper limit. As a result, FIG.
As shown in (1), after the DC component attenuates, there is a possibility that the signal is identified as being higher than the ground level, that is, as the High level. Therefore, the minimum value detection unit 31 detects the minimum value of the signal, that is, the noise level, and inputs the signal to the arithmetic processing unit 20 so that the control signal output unit 21 outputs the attenuation level adjustment unit 1.
The control signal is transmitted to 4, and the attenuation level is changed to not the ground level but the detected minimum value, that is, the noise level. As a result, a waveform due to attenuation does not occur in a portion that is originally Low, and it does not go above the ground level and data is not erroneously identified, so that the effect of noise components is eliminated and data is accurately identified. It becomes possible. FIG.
1 is obtained by adding an attenuation adjusting unit 15 to the configuration of the data receiving apparatus 2 shown in FIG. In FIG. 13, similarly to the configuration in FIG. 10, when data is processed by the processing unit 20, the ratio of data “1” to data “0” is calculated, and the calculation is performed by the control signal output unit 21. The result is transmitted as a control signal to the attenuation adjusting unit 15 to adjust the amount of attenuation of the DC component so that the ratio of the signal waveform to the ground level becomes equal in the vertical direction as shown in FIG. And the like, it is possible to reduce the influence of the fluctuation of the signal level. FIG. 14 shows a signal level when data “0” is input after a certain time t from a state where there is no input. In both cases where data “0” is continuously input and there is no input, the signal level cannot be distinguished because both are at the ground level. That is, it is impossible to identify where and how many bits “0” continues. Since the original level is the ground level, even if the signal level is attenuated or the DC component is attenuated as described above, there is no effect because the level does not change. Therefore, by adding additional data having a different length per bit from data "0" and data "1", for example, before the data, it is clarified that the data immediately after the additional data is the beginning of the data. So that data "0"
It is also possible to identify the data accurately even when is repeated. It is to be noted that a reduction in the data amount per unit can be minimized by making the length of one bit of the additional data shorter than that of the data. Next, when composing the additional data, if the high level or the low level continues even if the length per bit is made different, data "1" and data "0" become 1 respectively.
Since it becomes the same as the case where the configuration is continuous with bits or more, it is impossible to clarify the start of the data which is the original purpose. Therefore, the additional data can be clearly distinguished from data "0", data "1" and the continuous state of the data by preventing the signal level of the additional data from being high continuous or low continuous. It is possible to accurately identify data even when data “0” continues. Further, consider a case where data “0” and “1” are continuously input. If the data “1” continues, the signal level can be finally changed to a waveform that is higher or lower than the ground level by adjusting the signal level attenuating section 12 or the decay time as described above. On the other hand, when data “0” continues, it is possible to distinguish the beginning of the data by the additional data as described above, but since the data “0” is at a low level as a signal level, the DC component is also low. Even if the level, that is, the DC component is to be attenuated, the number of components to be attenuated originally is small, so that it becomes difficult to discriminate. The cause of the above-described problem is that a high-level signal having a large DC component is small even when additional data is included.
Therefore, the configuration of the additional data is set so that the high level is increased as long as not all of the configuration is at the high level and the data is not confused with the data. By doing so, a high-level signal that was not present only with the data “0” is added, the DC component also increases, the data can be easily identified with reference to the ground level, and the data Because the beginning is clear, the data can be identified accurately. It should be noted that the present invention is not limited to the data communication device of the above embodiment, and various modifications are possible within the scope of the contents described in the appended claims. It includes everything.

As described above, according to the first aspect of the present invention, data can be accurately identified even when a high-level signal or a low-level signal is continuously generated. Thus, it is possible to provide a data communication system capable of increasing the communication speed without limiting the transmission rate and accurately identifying the transmission signal. According to the second aspect of the invention, there is an effect that the decay time is appropriately adjusted in accordance with the magnitude of the noise, thereby enabling accurate identification of data. According to the third aspect of the invention, since the ratio of the signal waveform to the ground level can be adjusted to be equal, there is an effect that data can be accurately identified. According to the fourth aspect of the present invention, there is an effect that the influence of the fluctuation of the signal level due to noise or the like can be reduced to enable accurate identification of data. According to the fifth aspect of the invention, there is an effect that the influence of the noise component is reduced and the data can be accurately identified. According to the invention of claim 6, there is an effect that data can be accurately identified even when data "0" is continuously generated. Claim 7
In the described invention, the additional data is represented by data "0",
The data "1" and the continuous state of the data can be clearly distinguished, and the data can be accurately identified even when the data "0" is continuous. According to the eighth aspect of the present invention, the DC component is increased, the data can be easily identified based on the ground level, and the beginning of the data is clear, so that the data can be identified accurately. This has the effect of becoming

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a data communication system according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a data receiving device.

FIG. 3 is a waveform diagram before and after input in a DC component attenuation unit.

FIG. 4 is a waveform chart showing an example of a method of giving information according to a signal level.

FIG. 5 is a waveform diagram before and after input of a DC component attenuating unit according to another embodiment.

FIG. 6 is a block diagram showing a configuration of a data receiving device according to another embodiment.

FIG. 7 is a waveform diagram before and after input to a DC component attenuating unit according to another embodiment.

FIG. 8 is a block diagram showing a configuration of a data receiving device according to another embodiment.

FIG. 9 is a waveform diagram before and after input to a DC component attenuating unit according to another embodiment, and an explanatory diagram showing data reading points in an arithmetic processing unit.

FIG. 10 is a block diagram showing a configuration of a data receiving device according to another embodiment.

FIG. 11 is a block diagram showing a configuration of a data receiving device according to another embodiment.

FIG. 12 is a waveform diagram before and after input of a signal level attenuator according to another embodiment, and a waveform diagram before and after input of a DC component attenuator.

FIG. 13 is a block diagram showing a configuration of a data receiving device according to another embodiment.

FIG. 14 is an explanatory diagram showing input and data signal levels in a time axis.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 data transmitting device 2 data receiving device 3 human body 4 signal 10 rectifying unit 11 DC component attenuating unit 12 signal level attenuating unit 13 decay time adjusting unit 14 attenuating level adjusting unit 15 attenuation amount adjusting unit 20 arithmetic processing unit 21 control signal output unit 31 Minimum value detector

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[Procedure amendment]

[Submission date] March 15, 2000 (200.3.1.
5)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of the Invention] Data communication system

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data receiving apparatus of a data communication system for transmitting and receiving data, and more particularly to a data communication system for transmitting and receiving data using a human body as a transmission line.

[0002]

2. Description of the Related Art Conventionally, as a method of data communication between a data transmission device carried by a person and a data reception device installed near the same, a method using wired communication by cable connection, a method using light, radio waves, or the like. There is a method using wireless communication.

When data is transmitted from a data transmitting device to a data receiving device, in a method using wired communication, the device itself can be configured to be relatively inexpensive and small. However, it is necessary to connect the data transmitting device and the data receiving device with a cable before starting data transmission / reception, or to disconnect the cable after the data transmission / reception is completed, which is not always convenient for the user. There was a problem that it was not something. On the other hand, in the method using wireless communication, the operation of connecting a cable is not required, so that data communication can be easily performed. However, the problem is that the data communication device is expensive and large. Had a point.

[0004] As means for solving such a conventional problem, there are, for example, those described in JP-A-10-228524 and JP-A-10-229357. In these devices, a data communication device that transmits data from a data transmission device attached to a human body to a data reception device using the human body as a transmission path has been proposed. It is possible to use a device that is inexpensive and small in size, and it is possible to easily transmit and receive data because there is no need to connect a cable or the like.

When an amplitude modulation method or a modulation method using a pulse as a carrier is used, it is necessary to distinguish between high and low waveforms in order to finally identify data. As a countermeasure, if the DC component of the signal rectified in the data receiving device is deleted and a method of discriminating the high and low of the signal waveform based on the reference value (so-called ground) is used, the level fluctuation of the rectified waveform can be achieved. , Because the reference value fluctuates automatically due to the addition of noise,
Low can be effectively distinguished.

On the other hand, when increasing the data communication speed in a general communication system, the amount of data per unit time must be increased. For this purpose, there are measures such as increasing the carrier frequency, but considering hardware constraints,
For example, it is most effective to send one information by one bit of digital data.

When the data communication speed is increased by the above-described measures, the data communication apparatus using a human body as a transmission path has the following problems. That is, 1) Since rectification is generally performed using the charge / discharge characteristics of a capacitor, if the charge characteristics are improved in order to increase the rectification effect, the discharge characteristics deteriorate, and as a result, the data length becomes longer than the original data length. 2) Since one bit has one piece of information, when the same information is continuous, that is, when the signal level is considered, if the states of High and Low continue, the state becomes the same as the DC component. Is deleted, the information of the original waveform is lost.

In order to solve these problems, in order to solve the above problem 1), the data transmission device and the data reception device synchronize the data and forcibly discharge the data when the high state of the data ends. There is a measure such as deleting the specific discharge of the capacitor. For the above 2),
There is a way to change the protocol, that is, always use one combination of the signal level High and Low, or to limit the information, that is, do not use the form of information that follows the signal level High and Low. is there.

[0009]

However, in the above-mentioned data communication system using a human body as a transmission line, in a system for synchronizing data communication between a data transmitting device and a data receiving device, both devices are used. Since the communication system must always be in the same area and have an environment in which communication for synchronization can be performed, there is a problem that the use of the communication system is limited. Also, one piece of information must be at the signal level Hi.
gh, the method in which a combination of Low, since that would change the convey one information when Iupu protocol in order to increase the communication speed, had a problem that shall not meet the original purpose. In addition, signal level High,
In a method of not using an information form in which Low continues, for example, the amount of information is limited, which also has a problem that its use is limited.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to increase the communication speed without limiting the use of communication and to accurately identify a transmission signal. A communication system is provided.

[0011]

According to the first aspect of the present invention,
A data transmission device that performs amplitude modulation or modulation using a pulse as a carrier wave based on data to be transmitted and outputs a modulation signal from a portion attached to the human body, and a human body having the data transmission device attached thereto. A data receiving device for receiving a modulated signal output from the data transmitting device and demodulating the modulated signal, wherein the data receiving device rectifies a signal to demodulate the modulated signal. A rectifying unit, a DC component attenuating unit that removes a DC component of the signal rectified by the rectifying unit, and a signal level attenuating unit that attenuates the signal rectified by the rectifying unit at a predetermined cycle. It is characterized by the following.

According to a second aspect of the present invention, in the data communication system according to the first aspect, the data receiving device includes an arithmetic processing unit for performing arithmetic processing on the demodulated data. A process for attenuating the signal level of the data in the signal level attenuating unit is linked.

According to a third aspect of the present invention, in the data communication system according to the second aspect, the signal level attenuating unit has an attenuation time adjusting unit for adjusting an attenuation time, and the arithmetic processing unit is configured to execute a calculation based on a result of the arithmetic processing. A control signal output unit for outputting a control signal is provided, and the decay time of the signal level attenuating unit is adjusted based on the control signal from the control signal output unit.

According to a fourth aspect of the present invention, in the data communication system according to the third aspect, the DC component attenuating unit includes an attenuation amount adjusting unit for adjusting an amount of signal attenuation, and a control signal from the control signal output unit. The amount of attenuation of the DC component attenuating section is adjusted by the above method.

According to a fifth aspect of the present invention, in the data communication system according to any one of the first to fourth aspects, the data receiving device includes a minimum value detecting unit, and the signal level attenuating unit adjusts a signal attenuating level. An attenuation level adjusting section for adjusting an attenuation level of the signal level attenuating section by a control signal from the control signal output section.

According to a sixth aspect of the present invention, in the data communication system according to any one of the first to fifth aspects, the data transmitting apparatus is configured to discriminate data when performing modulation based on data to be transmitted. An additional data attachment unit for adding additional data to data is provided.

According to a seventh aspect of the present invention, in the data communication system according to the sixth aspect, the additional data attaching section includes:
Signal level is High or Lo for a predetermined time
It is characterized in that w-level signals are not generated continuously.

According to an eighth aspect of the present invention, in the data communication system according to the sixth or seventh aspect, the additional data appending section is configured to generate a high-level signal more frequently than a low-level signal. It is characterized by having done.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a data receiving apparatus of a data communication system according to an embodiment of the present invention will be described in detail with reference to FIGS.

FIG. 1 is a schematic diagram of a data communication system using a human body 3 as a transmission path. A signal 4 is transmitted from the data transmitting device 1 to the data receiving device 2 via the human body 3.
Here, the data transmitting apparatus 1 generates a signal and transmits the signal to the human body 3, and a transmission signal modulated based on data to be transmitted is applied to the human body. As its configuration, for example, the 2 is arranged so as to face the human body.
One electrode, an oscillating unit that generates an AC signal, a modulation unit that modulates the AC signal based on data to be transmitted, and outputs a modulation signal, and outputs a voltage corresponding to the modulation signal between the two electrodes. And a voltage application unit for applying a voltage to the power supply.

In FIG. 1, the data transmission device 1 is worn on the wrist, but the installation location is not particularly limited. Also, in FIG. 1, the data receiving device 2 exists outside the human body 3, but the data transmitting device 1
In the same manner as described above, it may be mounted on the human body 3 and the installation place is not limited. Note that the signal 4 is a composite signal obtained by adding a human body signal to the modulation signal.

FIG. 2 shows a part of the configuration of the data receiving apparatus 2. When the signal 4 is input to the data receiving device 2, the signal 4 is input to a rectifier 10 for demodulating a modulated signal via a filter, an amplifier, and the like. The signal input to the rectifier 10 is rectified in a form close to the original data signal. The rectified signal is input to the DC component attenuator 11, and the DC component of the signal is deleted.

FIG. 3A shows a waveform before input in the DC component attenuator 11, and FIG.
3 shows the waveform after input. From this, the input waveform Hi
gh and Low can be distinguished by whether the level is higher or lower than the ground level.

FIG. 4A shows a signal before information is given by the signal level, and FIG. 4B shows a signal after information is given by the signal level. In a method of giving one information by one bit, information of data “0” is assigned by a one-bit low level signal, and one bit of high information is assigned.
The information of data “1” is assigned by the signal of the level (see FIG. 4A). Also, one piece of information must be High,
In the measure to be performed by the combination of Low, the information of data “0” is allocated with a total of 2 bits of Low + High, and Low + High + H
The information of data “1” is assigned with a total of 2 bits of igh (see FIG. 4B). In other words, the latter requires 2.5 times the number of bits when expressing the same information of data “01” with respect to the former approach. That is, in the latter case, if the time per bit does not change, the amount of information per unit time decreases, that is, the transmission speed decreases in data communication.

FIG. 5 shows a waveform when data "1" is continuously input to the data receiving apparatus 2 by using the above-mentioned method of giving one information to one bit, and FIG. 11 shows a waveform before input, and (b) shows a waveform after input in the DC component attenuator 11. The state in which the data “1” continues is a state in which the High level continues in the signal level. In other words, in that state, Hig
Since there is no switching between h and Low, the DC level is constant instead of the AC state where the level changes, and when the DC component is deleted by the DC component attenuating unit 11, the signal level becomes the ground level, that is, the Low level. The waveform becomes indistinguishable if the signal level is higher or lower than the ground level.

FIG. 6 shows a data receiving apparatus 2 according to the present embodiment. FIG. 7 shows a data receiving apparatus 2 according to the present embodiment.
5A shows a waveform when data “1” is continuously input to the data receiving device 2, and FIG.
Shows the waveform before the input in (a), and (b) shows the waveform after the input in the DC component attenuator 11. The data “1”, that is, the high level signal is periodically attenuated to the ground level by the signal level attenuator 12. As a method of attenuating, for example, a discharge or the like by conduction with the ground is used. When the decay is stopped, the signal level becomes the high level again due to the specific charge of the rectifier 10. The state where these are repeated is the waveform shown in FIG. When this waveform is input to the DC component attenuator 11, the signal level attenuator 1
In contrast to the case where there is no attenuation due to
Since there is a switching of Low, that is, an AC component, the waveform does not all become Low level even after the DC component is deleted, and as shown in FIG. There will be high and low. As a result, even in a state where data “1”, that is, a high level signal is continuous, it is possible to accurately identify data based on the ground level.

FIG. 8 shows the configuration of the receiving apparatus 2 shown in FIG. 6 with the addition of wiring for linking the arithmetic processing section 20 and the signal level attenuating section 12. FIG. 9 shows a waveform when data “1” is continuously input to the data receiving device 2 in the data receiving device 2 according to the present embodiment.
Indicates a waveform before input in the DC component attenuator 11;
(B) shows a waveform after input in the DC component attenuator 11. In FIG. 9, arrows indicate data reading points by the arithmetic processing unit 20, and reading is performed at regular time intervals.

In FIG. 9, the time for attenuating the signal level is longer than in FIG.
The level is quite different from the original waveform that continues. However, since the data is read at the same High level as the original signal waveform, the arithmetic processing unit 20 can determine that the same data is being processed. This is because the arithmetic processing unit 20 and the signal level attenuating unit 12 cooperate with each other to prevent data from being read when the signal is attenuated. As shown in FIG. 9, the longer the attenuation time is, the shorter the High level time is, that is, the DC component that the High level has is reduced. As a result, the DC component deleted by the DC component attenuating unit 11 is reduced. Become
The High and Low levels with respect to the ground level are increased.

Thus, by cooperating, it is possible to control the waveform after the input to the DC component attenuating unit 11 without affecting the arithmetic processing unit 20, that is, affecting the accurate identification of data. It becomes.

That is, when the human body signal is small, the decay time is reduced, and as shown in FIG. 7, the center level of the waveform is set below ground, and when the human body signal is small, the decay time is lengthened, as shown in FIG. It is possible to adjust the center level of the waveform above ground.

FIG. 10 is obtained by adding a decay time adjusting section 13 and a control signal output section 21 to the configuration of the data receiving apparatus 2 shown in FIG.

When the information has a large number of data "1" components, the entire information has a large DC component, and if the decay time is short, the signal component is below the ground level as shown in FIG. . If the signal level fluctuates due to noise or the like in this state, the signal of data “1” becomes lower than the ground level, and there is a possibility that the signal is identified as data “0”. If the information contains a large amount of data "0", the DC component is small. Conversely, if the decay time is long, the signal component will be above the ground level as shown in FIG. There is a possibility that data “0” is identified as data “1”.

Therefore, while the data is being processed by the processing unit 20, the occurrence ratio of the data "1" to the data "0" is calculated, and the control signal output unit 21 uses the calculation result as a control signal. By transmitting the signal to the decay time adjusting unit 13, the decay time is adjusted, and as shown in FIG. 3, the ratio of the signal waveform to the ground level is made equal at the upper and lower sides, so that the signal level due to a human body signal and noise is reduced. This makes it possible to reduce the effects of fluctuations.

FIG. 11 shows the data receiving apparatus 2 shown in FIG.
The minimum value detection unit 31 and the attenuation level adjustment unit 14 are added to the configuration of FIG.

In the configuration shown in FIG. 11, waveforms before and after the signal level is attenuated by the signal level attenuator 12 and the DC component attenuator 1
FIG. 12 shows the waveform after the input of 1. As shown in FIG.
When a noise component is added to a Low level signal, a portion which is originally at a Low level has a waveform with the noise level as an upper limit after the signal level is attenuated as shown in FIG.
As a result, as shown in FIG. 12C, after the DC component attenuation, there is a possibility that the DC component is determined to be higher than the ground level, that is, the High level.

Then, the minimum value of the signal, that is, the noise level is detected by the minimum value detecting section 31 and input to the arithmetic processing section 20, whereby the control signal is transmitted from the control signal output section 21 to the attenuation level adjusting section 14. Then, the attenuation level is changed not to the ground level but to the detected minimum value, that is, the noise level. By this, Lo
The waveform due to attenuation does not occur at the point w, and it does not go above the ground level, and it does not mistakenly identify data, so it is possible to eliminate the influence of noise components and accurately identify data It becomes.

FIG. 13 shows the data receiving apparatus 2 shown in FIG.
And an attenuation adjusting unit 15 is added to the above configuration. FIG.
3, the ratio of data “1” to data “0” is calculated when the data is processed by the processing unit 20, and the calculation result is output by the control signal output unit 21. Is transmitted to the attenuation adjusting unit 15 as a control signal to adjust the attenuation of the DC component, so that the ratio of the signal waveform to the ground level becomes equal in the vertical direction as shown in FIG. Can reduce the influence of signal level fluctuations.

FIG. 14 shows a state where there is no input and a certain time t.
Hereinafter, the signal level when data "0" is input is shown. In both cases where data “0” is continuously input and there is no input, the signal level cannot be distinguished because both are at the ground level. That is, it is impossible to identify where and how many bits “0” continues. Since the original level is the ground level, even if the signal level is attenuated or the DC component is attenuated as described above, there is no effect because the level does not change.

Therefore, data "0" and data "1" are 1
By adding additional data having different lengths per bit, for example, before the data, it is possible to clarify that the data immediately after the additional data is the beginning of the data. It becomes possible to identify data accurately. It is to be noted that a reduction in the data amount per unit can be minimized by making the length of one bit of the additional data shorter than that of the data.

Next, in forming the additional data,
If the high level or low level continues even if the length per bit is made different, the result is the same as the case where data "1" and data "0" are continuous for one bit or more. Therefore, it becomes impossible to clarify the beginning of the data, which was the original purpose.

Therefore, the signal level of the additional data is High.
Continuation or low continuation, the additional data can be clearly distinguished from data "0", data "1" and the continuous state of those data, and the data "0" is continuous. In this case, data can be identified accurately.

Further, consider a case where data "0" and "1" are continuously input. If the data “1” continues, the signal level can be finally changed to a waveform that is higher or lower than the ground level by adjusting the signal level attenuating section 12 or the decay time as described above. On the other hand, when data “0” continues, it is possible to distinguish the beginning of the data by the additional data as described above, but since the data “0” is at a low level as a signal level, the DC component is also low. Even if the level, that is, the DC component is to be attenuated, the number of components to be attenuated originally is small, so that it becomes difficult to discriminate.

The cause of the problem described above is that Hi
This is because the signal of the gh level is small even if the additional data is included. Therefore, the configuration of the additional data is set so that the high level is increased as long as not all of the configuration is at the high level and the data is not confused with the data. By doing so, a high-level signal that was not present only with the data “0” is added, the DC component also increases, the data can be easily identified with reference to the ground level, and the data Because the beginning is clear, the data can be identified accurately.

It should be noted that the present invention is not limited to the data communication device of the above embodiment, and various modifications are possible within the scope of the contents described in the claims. Includes all of these.

[0045]

As described above, according to the first aspect of the present invention, data can be accurately identified even when a high-level signal or a low-level signal is continuously generated. Thus, it is possible to provide a data communication system capable of increasing the communication speed without limiting the transmission rate and accurately identifying the transmission signal.

According to the second aspect of the invention, there is an effect that the data can be accurately identified by appropriately adjusting the decay time for the magnitude of the noise.

According to the third aspect of the invention, since the ratio of the signal waveform to the ground level can be adjusted to be equal, there is an effect that data can be accurately identified.

According to the fourth aspect of the present invention, it is possible to reduce the influence of a change in signal level due to noise or the like, thereby enabling accurate identification of data.

According to the fifth aspect of the invention, there is an effect that the influence of the noise component is reduced and the data can be accurately identified.

According to the sixth aspect of the present invention, it is possible to accurately identify data even when data "0" is continuously generated.

According to the seventh aspect of the present invention, the additional data can be clearly distinguished from data "0", data "1" and a continuous state of the data, and the data "0".
This has the effect that the data can be identified accurately even when the characters are consecutive.

According to the eighth aspect of the present invention, the DC component is increased, the data can be easily identified on the basis of the ground level, and the beginning of the data is clear, so that the data can be accurately identified. This has the effect that it becomes possible.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a data communication system according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a data receiving device.

FIG. 3 is a waveform diagram before and after input in a DC component attenuation unit.

FIG. 4 is a waveform chart showing an example of a method of giving information according to a signal level.

FIG. 5 is a waveform diagram before and after input of a DC component attenuating unit according to another embodiment.

FIG. 6 is a block diagram showing a configuration of a data receiving device according to another embodiment.

FIG. 7 is a waveform diagram before and after input to a DC component attenuating unit according to another embodiment.

FIG. 8 is a block diagram showing a configuration of a data receiving device according to another embodiment.

FIG. 9 is a waveform diagram before and after input to a DC component attenuating unit according to another embodiment, and an explanatory diagram showing data reading points in an arithmetic processing unit.

FIG. 10 is a block diagram showing a configuration of a data receiving device according to another embodiment.

FIG. 11 is a block diagram showing a configuration of a data receiving device according to another embodiment.

FIG. 12 is a waveform diagram before and after input of a signal level attenuator according to another embodiment, and a waveform diagram before and after input of a DC component attenuator.

FIG. 13 is a block diagram showing a configuration of a data receiving device according to another embodiment.

14 is an explanatory diagram showing a signal level in our Keru input and data time on the axis.

[Description of Signs] 1 Data transmission device 2 Data reception device 3 Human body 4 Signal 10 Rectification unit 11 DC component attenuation unit 12 Signal level attenuation unit 13 Attenuation time adjustment unit 14 Attenuation level adjustment unit 15 Attenuation amount adjustment unit 20 Arithmetic processing unit 21 Control signal output unit 31 Minimum value detection unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor ▲ Satoshi Ii No. 1048 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Works, Ltd. Inside the company (72) Inventor Yoshiko Suzuki Inside Matsushita Electric Works Co., Ltd.

Claims (8)

[Claims] 1. A data transmission device for performing amplitude modulation or modulation using a pulse as a carrier wave based on data to be transmitted, and outputting a modulated signal from a portion attached to a human body, and attaching the data transmission device. A data receiving device that receives a modulated signal output from the data transmitting device by touching a human body, and demodulates the modulated signal. The data receiving device demodulates the modulated signal. A rectifying unit for rectifying the signal, a DC component attenuating unit for removing a DC component of the signal rectified by the rectifying unit, and a signal level attenuating unit for attenuating the signal rectified by the rectifying unit at a predetermined cycle. A data communication system, comprising: 2. The data receiving apparatus according to claim 1, further comprising an arithmetic processing unit for performing arithmetic processing on the demodulated data, and coordinating the reading of the data by the arithmetic processing unit and the processing of attenuating the signal level of the data by the signal level attenuating unit. 2. The data communication system according to claim 1, wherein the data communication is performed. 3. The signal level attenuating section has a decay time adjusting section for adjusting a decay time, the arithmetic processing section has a control signal output section for outputting a control signal based on a result of the arithmetic processing, and the control signal 3. The data communication system according to claim 2, wherein an attenuation time of said signal level attenuation unit is adjusted based on a control signal from an output unit. 4. The apparatus according to claim 1, wherein the DC component attenuator includes an attenuation adjuster that adjusts an amount of signal attenuation, and the amount of attenuation of the DC component attenuator is adjusted by a control signal from the control signal output unit. The data communication system according to claim 3, wherein: 5. The data receiving device includes a minimum value detecting unit, the signal level attenuating unit has an attenuation level adjusting unit that adjusts an attenuation level of a signal, and the signal level attenuating unit adjusts the attenuation level of the signal by a control signal from the control signal output unit. 5. The data communication system according to claim 1, wherein an attenuation level of the signal level attenuator is adjusted. 6. The data transmitting apparatus according to claim 1, further comprising an additional data attachment unit for adding additional data for distinguishing the data to the data when performing modulation based on the data to be transmitted. The data communication system according to claim 1, wherein: 7. The data communication system according to claim 6, wherein said additional data attachment unit prevents a signal of a high level or a low level from being continuously generated for a predetermined time. 8. The data communication system according to claim 6, wherein the additional data attachment unit is configured to generate a signal of a high level signal more frequently than a signal of a low level signal.