JP4257361B2 - Electric field detection optical device and transceiver - Google Patents

Description

  The present invention relates to an electric field detection optical device that detects an electric field by modulating the light intensity of a laser beam based on an electric field to be detected, and a transceiver including such an electric field detection optical device.

  In recent years, attention has been focused on a new concept computer that can be worn and operated on a human body like clothing. This computer is called a wearable computer and can be realized by reducing the size and performance of the portable terminal.

  In addition, research on a technique for performing data communication between a plurality of wearable computers via a human body (living body) such as a human arm, shoulder, and torso is also progressing, and this technique has already been proposed in patent documents (for example, , See Patent Document 1). FIG. 1 shows an image diagram when communication between a plurality of wearable computers is performed via such a human body. As shown in the figure, the wearable computer 1 constitutes a set with a transceiver 3 ′ in contact with the wearable computer 1, and the human body is different from the other wearable computer 1 and transceiver 3 ′. Data communication can be performed via the. The wearable computer 1 is installed on a PC (personal computer) 5 other than the wearable computer 1 attached to a human body and a transceiver 3'a installed on a wall, or on the PC 5 and a floor. Data communication with the set of transceivers 3'b is also possible. However, the PC 5 in this case is not in contact with each other like the wearable computer 1 and the transceiver 3 ′, and is connected to the transceivers 3 ′ a and 3 ′ b via the cable 4.

  For data communication through the human body, signal detection technology based on electro-optic techniques using laser light and electro-optic crystals is used to generate an electric field based on information (data) to be transmitted. Information is transmitted and received by receiving information based on the electric field induced in the human body. The technique of data communication via the human body will be described in more detail with reference to FIG.

  FIG. 2 is an overall configuration diagram of a transceiver main body 30 ′ used for data communication via the human body (living body 100). As shown in FIG. 2, the transceiver body 30 ′ is used in contact with the living body 100 through the transmission / reception electrode 105 ′ and the insulating film 107 ′. The transceiver body 30 ′ receives the data supplied from the wearable computer 1 via the I / O (input / output) circuit 101 and transmits the data to the transmission unit 103. In the transmitting unit 103, an electric field is induced in the living body 100, which is an electric field transmission medium, from the transmission / reception electrode 105 ′ through the insulating film 107 ′, and this electric field is attached to another part of the living body 100 via the living body 100. To the transceiver 3 '.

  The transceiver body 30 ′ receives the electric field induced and transmitted to the living body 100 from another transceiver 3 ′ attached to another part of the living body 100 via the insulating film 107 ′ by the transmission / reception electrode 105 ′. . In the electric field detection optical unit 110 ′ constituting the electric field detection optical device 115 ′, the received electric field is applied (applied) to the electro-optic crystal to cause a change in polarization or intensity in the laser light. The light receiving circuit 152 ′ constituting the electric field detection optical device 115 ′ receives the laser beam whose polarization has been changed or has changed its intensity and converts it into an electrical signal, and performs signal processing such as amplification of the electrical signal. Further, the signal processing circuit 116 constituting the receiving circuit 113 removes frequency components other than the frequency component related to the reception information that is the electric field detection target from the electric signals having various frequencies by the band pass filter constituting the receiving circuit 113. (In other words, by extracting only the frequency component related to the reception information), signal processing such as noise removal of the electric signal is performed. The waveform shaping circuit 117 constituting the receiving circuit 113 performs waveform shaping (signal processing) of the electric signal that has passed through the signal processing circuit 116 and supplies the waveform to the wearable computer 1 via the input / output circuit 101.

  Also, as shown in FIG. 3, the electrodes can be divided into two for transmission and reception. That is, the transmission unit 103 induces an electric field from the transmission electrode 105 ′ a to the living body 100 that is an electric field transmission medium via the insulating film 107 ′ a. On the other hand, the reception electrode 105 ′ b receives an electric field induced and transmitted to the living body 100 from another transceiver 3 ′ attached to another part of the living body 100 via the insulating film 107 ′ b. Other configurations and operations thereof are the same as those in FIG.

  For example, as shown in FIG. 1, the wearable computer 1 attached to the right arm induces an electrical signal related to transmission data as an electric field in the living body 100, which is an electric field transmission medium, by the transceiver 3 ', Communicate to 100 other sites. On the other hand, in the wearable computer 1 attached to the left arm, the electric field transmitted from the living body 100 can be returned to the electrical signal by the transceiver 3 ′ and then received as received data.

By the way, a portable terminal such as a wearable computer 1 or a portable terminal such as a cellular phone is required to be miniaturized in consideration of convenience of being attached to a living body 100 or being carried as shown in FIG.
JP 2001-352298 A (page 4-5, FIG. 1-5)

  However, as computers and portable terminals have become smaller, there has been a problem that it becomes difficult to input information to the computer and portable terminals.

  On the other hand, the electric field detection optical unit 110 ′ in the transceiver body 30 ′ includes a polarization modulator that converts a polarization change of laser light into an intensity change, an electroabsorption (EA) light intensity modulator, a Mach-Zehnder light Some light intensity modulators, such as an intensity modulator, directly convert changes in the intensity of laser light.

  Therefore, the electric field detection optical unit 110′a and the light receiving circuit 152′a using the polarization modulator 123 will be described with reference to FIGS. 4 and 5, and then the light intensity modulation will be described with reference to FIGS. The electric field detection optical unit 110′b and the light receiving circuit 152′b using the detector 124 will be described.

  First, as shown in FIG. 4, the electric field detection optical unit 110′a using the polarization modulator 123 includes a polarization modulator such as a current source 119, a laser diode 121, a collimator lens 133, and an electro-optic element (electro-optic crystal). 123, first and second wave plates 135 and 137, a deflecting beam splitter 139 ′, and first and second condenser lenses 141a and 141b.

  The light receiving circuit 152′a includes a first photodiode 143a, a first load resistor 145a, and a first constant voltage source 147a, and a second photodiode 143b, a second load resistor 145b, and a second constant voltage source 147b. And a differential amplifier 112.

  Among these, the polarization modulator 123 has sensitivity only to an electric field coupled in a direction perpendicular to the traveling direction of the laser light emitted from the laser diode 121, and the optical characteristic, that is, the birefringence is controlled by the electric field strength. It changes, and it is comprised so that the polarization of a laser beam may be changed by the change of this birefringence. A first electrode 125 and a second electrode 127 are provided on both side surfaces of the polarization modulator 123 facing in the vertical direction in the figure. The first electrode 125 and the second electrode 127 are opposed to the traveling direction of the laser light from the laser diode 121 in the polarization modulator 123 at a right angle, and can couple the electric field to the laser light at a right angle. .

  The electric field detection optical unit 110 ′ a is connected to the reception electrode 105 ′ b through the first electrode 125. The second electrode 127 facing the first electrode 125 is connected to the ground electrode 131 and is configured to function as a ground electrode with respect to the first electrode 125. When the reception electrode 105 ′ b detects the electric field induced and transmitted to the living body 100, the reception electrode 105 ′ b transmits the electric field to the first electrode 125 and couples it to the polarization modulator 123 via the first electrode 125. Can do.

  As a result, the laser light output from the laser diode 121 by the current control of the current source 119 is converted into parallel light through the collimator lens 133, and the polarization state of the laser light that has become parallel light is adjusted by the first wavelength plate 135. Then, the light enters the polarization modulator 123. The laser light incident on the polarization modulator 123 propagates between the first and second electrodes 125 and 127 in the polarization modulator 123. During the propagation of the laser light, the reception electrode 105′b as described above. When the electric field induced and transmitted to the living body 100 is detected and this electric field is coupled to the polarization modulator 123 via the first electrode 125, the electric field is connected from the first electrode 125 to the ground electrode 131. It is formed toward the second electrode 127. Since this electric field is perpendicular to the traveling direction of the laser light incident on the polarization modulator 123 from the laser diode 121, the birefringence, which is an optical characteristic of the polarization modulator 123, changes, and thereby the polarization of the laser light is changed. Change.

  Next, the laser light whose polarization has been changed by the electric field from the first electrode 125 in the polarization modulator 123 is adjusted in the polarization state by the second wave plate 137 and is incident on the polarization beam splitter 139 ′. The polarization beam splitter 139 ′ separates the laser light incident from the second wave plate 137 into a P wave and an S wave and converts them into a change in light intensity. The laser light separated into the P-wave component and the S-wave component by the polarization beam splitter 139 ′ is condensed by the first and second condenser lenses 141a and 141b, respectively, and then the first constituting the photoelectric conversion means. The first and second photodiodes 143a and 143b can convert the P-wave optical signal and the S-wave optical signal into respective electric signals and output them. Note that the current signals output from the first and second photodiodes 143a and 143b are respectively supplied from the first load resistor 145a and the first constant voltage source 147a, and the second load resistor 145b and the second constant voltage source 147b. After being converted into a signal, a voltage signal (intensity modulation signal) related to received information can be taken out differentially by the differential amplifier 112. The extracted voltage signal is supplied to the signal processing circuit 116 shown in FIGS.

  Further, in the differential amplifier 112, as shown in FIG. 5, the voltage signal Sa from the first photodiode 143a and the voltage signal Sb from the second photodiode 143b are out of phase by 180 °. The components are amplified and the noise of the in-phase laser light is subtracted and removed.

  The signal processing circuit 116 shown in FIGS. 2 and 3 performs noise removal signal processing, the waveform shaping circuit 117 performs waveform shaping signal processing, and then the wearable computer 1 via the input / output circuit 101 Will be supplied.

  Next, the electric field detection optical unit 110'b and the light receiving circuit 152'b using the light intensity modulator 124 will be described with reference to FIGS. Note that the same reference numerals are assigned to the same components as those of the electric field detection optical unit 110 ′ a and the light receiving circuit 152 ′ a using the polarization modulator 123.

  First, as shown in FIG. 6, the electric field detection optical unit 110′b using the light intensity modulator 124 includes a current source 119, a laser diode 121, a collimator lens 133, an electroabsorption (EA) light intensity modulator, and a Mach-Zehnder. A light intensity modulator 124 such as a mold-type light intensity modulator and a condenser lens 141 are included.

  The light receiving circuit 152 ′ b includes a photodiode 143, a load resistor 145, a constant voltage source 147, and a (single) amplifier 118.

  Among these, the light intensity modulator 124 is configured such that the light intensity of the light passing therethrough varies depending on the electric field intensity to be coupled. A first electrode 125 and a second electrode 127 are provided on both side surfaces of the light intensity modulator 124 facing in the vertical direction in the drawing. The first electrode 125 and the second electrode 127 face each other at right angles to the traveling direction of the laser light from the laser diode 121 in the light intensity modulator 124, and can couple the electric field at right angles to the laser light. it can.

  The electric field detection optical unit 110 ′ b is connected to the reception electrode 105 ′ b through the first electrode 125. The second electrode 127 facing the first electrode 125 is connected to the ground electrode 131 and is configured to function as a ground electrode with respect to the first electrode 125. When receiving the electric field induced and transmitted to the living body 100, the receiving electrode 105′b transmits the electric field to the first electrode 125 and is coupled to the light intensity modulator 124 via the first electrode 125. be able to.

  Here, an electroabsorption (EA) light intensity modulator 124a, which is an example of the light intensity modulator 124, will be briefly described with reference to FIG.

  As shown in FIG. 7, when a laser beam having a constant light intensity is incident, the electroabsorption optical intensity modulator 124a maximizes the intensity of the incident laser light according to the detection signal related to the electric field. It is a modulator that changes the intensity. That is, the light intensity of the incident laser light is attenuated based on the detection signal related to the electric field.

  A Mach-Zehnder light intensity modulator 124b, which is an example of the light intensity modulator 124, will be briefly described with reference to FIG.

  As shown in FIG. 8, the Mach-Zehnder light intensity modulator 124b is formed with two waveguides 203a and 203b having different refractive indexes of light from the substrate 201, and is incident through the lens 205. The laser light is confined in the waveguides 203a and 203b and branched. The branched laser light is coupled by applying an electric field from the first electrode 125 and the second electrode 127, and then the laser light is emitted through the lens 207. By applying an electric field to one of the laser beams, the phase can be slightly delayed or advanced compared to a laser beam that does not apply an electric field.

  Returning to FIG. 6, the laser light output from the laser diode 121 by the current control of the current source 119 is converted into parallel light through the collimator lens 133, and the laser light that has become parallel light enters the light intensity modulator 124. . The laser light incident on the light intensity modulator 124 propagates between the first and second electrodes 125 and 127 in the light intensity modulator 124. During the propagation of the laser light, the reception electrode 105 is used as described above. When 'b detects the electric field transmitted by being induced in the living body 100 and couples the electric field to the light intensity modulator 124 through the first electrode 125, the electric field is connected from the first electrode 125 to the ground electrode 131. The second electrode 127 is formed toward the second electrode 127. Due to the coupling of the electric field, laser light having a changed light intensity is emitted and received by the photodiode 143 of the light receiving circuit 152 ′ b through the condenser lens 141. As a result, the current signal output from the photodiode 143 is converted into a voltage signal by the load resistor 145 and the constant voltage source 147 before being output. The The output voltage signal is amplified by the amplifier 118 and then supplied to the signal processing circuit 116 shown in FIGS.

  The signal processing circuit 116 shown in FIGS. 2 and 3 performs noise removal signal processing, the waveform shaping circuit 117 performs waveform shaping signal processing, and then the wearable computer 1 via the input / output circuit 101 Will be supplied.

  However, the light intensity modulator 124 shown in FIG. 6 differs from the modulator that converts the polarization change of the laser light into the intensity change like the polarization modulator 123 shown in FIG. Since the intensity modulation signal could not be extracted, differential detection could not be performed. If the output of the light intensity modulator 124 is directly received by the photodiode 143 without performing differential detection, the noise of the laser beam cannot be removed, and the S / N of the received signal is deteriorated, resulting in a deterioration in communication quality. It was happening.

  By the way, as shown in FIG. 9, there are cases where a pair of the transceiver 3 ′ and the wearable computer 1 is held by a human hand (living body 100). The transceiver 3 ′ shown in FIG. 9 has a configuration in which a transceiver main body 30 ′ is attached to the bottom of the inner wall surface of an insulating case 33 made of an insulator, and a battery 6 for driving the transceiver main body 30 ′ is attached to the top surface thereof. It has become. Further, a transmission / reception electrode 105 ′ is attached to the bottom of the outer wall surface of the insulating case 33, and the transmission / reception electrode 105 ′ is covered with an insulating film 107 ′. Note that portions other than the operation / input surface of the wearable computer 1 are covered with an insulating case 11.

  However, when the transceiver 3 ′ is held by hand as shown in FIG. 9, even if the transmission electric field E1 is induced from the transmission / reception electrode 105 ′ to the human hand (living body 100), a part of the electric field E2 is generated. ', E3' returns from the hand to the transceiver 3 'through the side surface of the insulating case 33. Therefore, there has been a problem that the transceiver 3 'does not perform a normal transmission operation.

  The present invention has been made in view of the above-described circumstances, and even in an electric field detection optical device using a light intensity modulator for electric field detection and a transceiver including the electric field detection optical device, communication quality is deteriorated. This is intended to suppress the above.

In order to achieve the above object, the invention according to claim 1 is an electric field detection optical device for detecting the electric field by modulating the light intensity of the laser light based on the electric field to be detected, the electric field detection optical unit and has a light receiving circuit, wherein the electric field detection optical section includes a laser beam emitting unit, a branching unit that branches the laser light emitted from the laser beam emitting unit in different first and second laser beams, electric having said detection structure field Ru coupled eligible to optical crystal, based on the combined field, said first light intensity modulation means for modulating the light intensity of the laser beam passing through said electrooptic crystal And an optical variable attenuator that attenuates the light intensity of the second laser light branched by the branching means and corrects an unbalance with respect to the light intensity of the first laser light modulated by the light intensity modulating means; , the And, the light receiving circuit, the light intensity of the first light / voltage converting means for converting the light intensity of the first laser beam into a voltage signal modulated by the modulating means, said second attenuated by the variable optical attenuator a second optical / voltage converting means for converting the intensity of the laser beam into a voltage signal, thus converted into the said first voltage signal converted by the light / voltage converting means second light / voltage converting hand stage The gist of the present invention is an electric field detection optical device having differential amplification means for differentially amplifying the voltage signal.

The invention according to claim 2, by modulating the basis of the light intensity of the record laser light into an electric field to be detected, a field detecting optical system for detecting the electric field, the electric field detecting optical section and a light receiving circuit And the electric field detection optical unit includes: a laser beam emitting unit; a branching unit that branches the laser beam emitted from the laser beam emitting unit into different first and second laser beams; A light intensity modulation means for modulating the light intensity of the first laser light passing through the electro-optic crystal based on the combined electric field. The light receiving circuit includes: a first light / current converting unit that converts the light intensity of the first laser light modulated by the light intensity modulating unit into a current signal; and the first light / current converting unit. A first voltage source for providing a reverse bias voltage, A first optical / voltage converting means first to the load resistance and, in the configuration for converting the current signal converted by the first optical / current converting means into a voltage signal, a second branched by said branching means A second light / current converting means for converting the intensity of the laser light into a current signal; a second voltage source for applying a reverse bias voltage to the second light / current converting means; and the second light. A second load resistor for converting the current signal converted by the current / current converting means into a voltage signal, and a voltage converted by the first light / voltage converting means. Differential amplification means for differentially amplifying a signal and the voltage signal converted by the second light / voltage conversion means, and at least one of the first load resistance and the second load resistance is The gist is that it is a variable resistor.

The invention according to claim 3, by modulated based light intensity Les laser light to an electric field to be detected, a field detecting optical system for detecting the electric field, the electric field detecting optical section and a light receiving circuit And the electric field detection optical unit includes: a laser beam emitting unit; a branching unit that branches the laser beam emitted from the laser beam emitting unit into different first and second laser beams; A light intensity modulation means for modulating the light intensity of the first laser light passing through the electro-optic crystal based on the combined electric field. The light receiving circuit includes: a first light / current converting unit that converts the light intensity of the first laser light modulated by the light intensity modulating unit into a current signal; and the first light / current converting unit. A first voltage source for providing a reverse bias voltage, A first optical / voltage converting means first to the load resistance and, in the configuration for converting the current signal converted by the first optical / current converting means into a voltage signal, a second branched by said branching means A second light / current converting means for converting the intensity of the laser light into a current signal; a second voltage source for applying a reverse bias voltage to the second light / current converting means; and the second light. A second load resistor for converting the current signal converted by the current / current converting means into a voltage signal, and a voltage converted by the first light / voltage converting means. Differential amplification means for differentially amplifying the signal and the voltage signal converted by the second light / voltage conversion means, and at least one of the first voltage source and the second voltage source Is a variable voltage source.

The invention according to claim 4 is the invention according to any one of claims 1 to 3 , wherein the light receiving circuit includes the voltage signal converted by the first light / voltage conversion means and the second light / voltage. The gist of the invention is to further include variable amplification means for amplifying at least one of the voltage signals converted by the voltage conversion means.

In order to achieve the above object, the invention according to claim 5 is a transceiver capable of receiving information via the electric field transmission medium by receiving information based on the electric field induced in the electric field transmission medium. The electric field detection optical device according to any one of claims 1 to 4 , a signal processing circuit that at least removes noise from the voltage signal output from the electric field detection optical device, 2. The light in the electric field detection optical unit according to claim 1 , based on noise detection means for detecting a magnitude of a noise component of the voltage signal output from the signal processing circuit, and detection data output from the noise detection means. The light attenuation amount of the variable attenuator, the resistance value of the variable resistor in the light receiving circuit according to claim 2, the voltage value of the variable voltage source in the light receiving circuit according to claim 3, or 4 a control signal generator for generating a control signal for variably controlling the voltage gain of the variable amplifying means according to a transceiver comprising the the gist.

  According to the present invention, the laser beam is branched (separated) before the laser beam is incident on the light intensity modulating unit, and one is input to the light intensity modulating unit and used as the laser beam for detecting the electric field, and the other is the light intensity Since it is used only as laser light for removing noise from the laser light without being input to the modulation means, the intensity modulation signal cannot be extracted differentially like a modulator that converts the polarization change of the laser light into intensity change. Even when the light intensity modulation means is used, there is an effect that the noise of the laser beam can be removed.

  Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as “embodiment”) will be described with reference to the drawings.

  Note that the transceiver 3 according to the embodiment of the present invention induces an electric field based on information to be transmitted in the electric field transmission medium (the living body 100 or the like), while information based on the electric field induced in the electric field transmission medium. The transceiver is capable of transmitting and receiving information via the electric field transmission medium by receiving.

  First, an embodiment relating to a transceiver capable of easily inputting information to a particularly downsized wearable computer will be described.

<First Embodiment>
The first embodiment will be described below with reference to the drawings.

  FIG. 10 is an image view of the front showing the usage state of the transceiver 3 and the wearable computer 1 according to the first embodiment. FIG. 11 is an image view of a plane showing the usage state.

  As shown in FIG. 10, an insulating insulating sheet 301 is attached on the plane of the table 300, and an electric field transmission sheet 302 capable of transmitting an electric field is attached on the plane of the insulating sheet 301. Furthermore, transmitters A and B are arranged at different angles on the plane of the electric field transmission sheet 302, respectively. As shown in FIG. 11, this arrangement position is arbitrarily different when the electric field transmission sheet 302 is rectangular.

  Further, the transmitters A and B have the same configuration as the transmission unit 103, the transmission electrode 105′a, and the insulating film 107′a as shown in FIG. 3, respectively, and the transmission frequencies fa, An electric field based on the electric signal related to fb can be induced in the electric field transmission sheet 302.

  FIG. 13 is an overall configuration diagram of the transceiver body 30a in the transceiver 3 according to the present embodiment.

  As shown in FIG. 13, the transceiver body 30a includes an I / O (input / output) circuit 101, a transmission unit 103, a transmission electrode 105a, insulating films 107a and 107b, a reception electrode 105b, an electric field detection optical device 115, and a signal processing circuit 116. , And the waveform shaping circuit 117 is the same as the conventional transceiver body 30 ′. Further, the transceiver main body 30a of the present embodiment includes bandpass filters 11a and 11b, signal intensity measuring units 13a and 13b, a position conversion processing unit 15, and a memory 17.

  Among these, the I / O circuit 101 is a circuit in which the transceiver body 30a inputs and outputs information (data) with an external device such as the wearable computer 1. The transmission unit 103 is configured by a transmission circuit that induces an electric field related to this information in the living body 100 based on information (data) output from the I / O circuit 101. The transmission electrode 105a is an electrode used for inducing an electric field with respect to the living body 100 by the transmission unit 103, and is used as a transmission antenna. The insulating film 107 a is an insulating film disposed between the transmission electrode 105 a and the living body 100, and plays a role of preventing the transmitting electrode 105 a from directly contacting the living body 100.

  The receiving electrode 105b receives an electric field induced and transmitted to the living body 100 from the wearable computer 1, the transceiver 3 ′, the PC 5 and the transceivers 3′a and 3′b attached to other parts of the living body 100. This is an electrode used for receiving and used as a receiving antenna. The insulating film 107b is an insulating film disposed between the receiving electrode 105b and the living body 100, like the insulating film 107a.

  Further, the electric field detection optical device 115 has a function of detecting the electric field received by the reception electrode 105b and converting the electric field into reception signals as an electric signal. The signal processing circuit 116 further includes an amplification unit 114 that amplifies the electric signal transmitted from the electric field detection optical device 115 and a band pass filter 151. The band-pass filter 151 limits the band of the electric signal output from the amplifying unit 114 and removes unnecessary noise and unnecessary signal components, so that among the electric signals output from the amplifying unit 114, FIG. The filter circuit has a characteristic of allowing only signal components of a certain frequency band (f1 to f2) for information communication to pass as shown in FIG.

  The waveform shaping circuit 117 is a circuit that performs waveform shaping (signal processing) on the electrical signal transmitted from the signal processing circuit 116 and supplies the waveform to the wearable computer 1 via the I / O circuit 101.

  Further, the band pass filter 11a limits the band of the electric signal output from the amplifying unit 114 and removes unnecessary noise and unnecessary signal components. 12 is a filter circuit having a characteristic of allowing only the signal component of the frequency band (fa) for the transmitter A to pass as shown in FIG. The signal strength measuring unit 13a is a circuit that measures the signal strength of the electrical signal related to the signal component passed by the band pass filter 11a.

  On the other hand, the band-pass filter 11b limits the band of the electric signal output from the amplifying unit 114 and removes unnecessary noise and unnecessary signal components, so that, among the electric signals output from the amplifying unit 114, FIG. 12 is a filter circuit having a characteristic of passing only signal components of the frequency band (fb) for the transmitter B as shown in FIG. The signal strength measuring unit 13b is a circuit that measures the signal strength of the electrical signal related to the signal component passed by the band pass filter 11b.

  The memory 17 is a storage unit that stores an intensity difference between two electrical signals and a specific position in a two-dimensional space in association with each other. In the present embodiment, an arbitrary position on the electric field transmission sheet 302 shown in FIGS. 10 and 11 is associated with an intensity difference in advance. Further, the association between the intensity difference and the specific position stored in the memory 17 can be rewritten via an I / O circuit 101 from an external device such as the wearable computer 1.

  The position conversion processing unit 15 calculates the intensity difference between the signal intensity measured by the signal intensity measuring unit 13 a and the signal intensity measured by the signal intensity measuring unit 13 b, and the intensity difference and the intensity stored in the memory 17. It is a processing device such as a CPU (Central Processing Unit) that performs processing for converting the calculated intensity difference into a specific position in the two-dimensional space by collating the difference.

  Subsequently, a position specifying method using the transceiver main body 30a and the transmitters A and B according to the present embodiment will be described.

  As shown in FIGS. 10 and 11, a person who wears the wearable computer 1 and the transceiver 3 in a state where the transmitters A and B are installed and driven on the electric field transmission sheet 302 is moved to a specific position on the electric field transmission sheet 302. Touch α. Thereby, the receiving electrode 105b receives the electric fields from the transmitters A and B through the finger (living body 100) and the insulating film 107b. In the electric field detection optical device 115, the received electric field is coupled (applied) to an electro-optic crystal (not shown) in the electric field detection optical device 115, converted into an electric signal, and then transmitted to the signal processing circuit 116. The amplification unit 114 of the signal processing circuit 116 amplifies the electric signal and transmits it to the bandpass filter 151. However, the electrical signal related to the electric field from the transmitters A and B does not pass through the band pass filter 116.

  The electrical signal transmitted from the amplifying unit 114 is also transmitted to the bandpass filters 11a and 11b.

  And in the band pass filter 11a, among the electric signals related to the electric field from the transmitters A and B, the signal component of only the band (fa) for the transmitter A is passed and transmitted to the signal intensity measuring unit 13a. The signal strength measuring unit 13a measures the signal strength of the electrical signal related to the signal component that has passed through the bandpass filter 11a.

  On the other hand, in the band pass filter 11b, among the electric signals related to the electric fields from the transmitters A and B, the signal component of only the band (fb) for the transmitter B is passed and transmitted to the signal intensity measuring unit 13b. The signal strength measuring unit 13b measures the signal strength of the electrical signal related to the signal component passed by the band pass filter 11b.

  Next, the position conversion processing unit 15 calculates an intensity difference between the signal intensity measured by the signal intensity measuring unit 13 a and the signal intensity measured by the signal intensity measuring unit 13 b and stores the intensity difference in the memory 17. By collating with the intensity difference, a process of converting the calculated intensity difference into a specific position α in the two-dimensional space on the electric field transmission sheet 202 is performed.

  Finally, the position information (data) of the specific position α obtained by the position conversion processing unit 15 is transmitted from the position conversion processing unit 15 to the wearable computer 1 via the I / O circuit 101.

  As described above, according to the present embodiment, the intensity difference between the signal intensity measured by the signal intensity measuring unit 13 a and the signal intensity measured by the signal intensity measuring unit 13 b is calculated and stored in the memory 17. By comparing the calculated intensity difference to a specific position in the two-dimensional space by collating with the intensity difference, the position of the specific position α touched by the finger (living body 100) in the electric field transmission sheet 302 Since information can be input to the wearable computer 1 or the like, there is an effect that information input to the wearable computer 1 or the like can be easily performed.

  In the above embodiment, the position conversion processing unit 15 calculates the intensity difference between the signal intensity measured by the signal intensity measuring unit 13a and the signal intensity measured by the signal intensity measuring unit 13b. However, the present invention is not limited to this. An intensity ratio between the signal intensity measured by the signal intensity measuring unit 13a and the signal intensity measured by the signal intensity measuring unit 13b may be calculated. However, in this case, the memory 17 needs to store the intensity ratio between the two electrical signals and the specific position in the two-dimensional space in association with each other.

<Second Embodiment>
Subsequently, a second embodiment will be described with reference to the drawings.

  FIG. 14 is an overall configuration diagram of a transceiver main body 30b in the transceiver according to the second embodiment. In addition, about the same structure as the said 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The phase detector 23a shown in FIG. 14 is a circuit that detects the phase of the electrical signal related to the signal component passed by the bandpass filter 11a. The phase detector 23b is a circuit that detects the phase of the electrical signal related to the signal component passed by the bandpass filter 11b.

  The memory 27 is a storage unit that stores a phase difference between two electrical signals and a specific position in a two-dimensional space in association with each other. Here, an arbitrary position on the electric field transmission sheet 302 shown in FIGS. 10 and 11 and a phase difference are associated in advance. Further, the correlation between the phase difference and the specific position stored in the memory 27 can be rewritten via the I / O circuit 101 from an external device such as the wearable computer 1.

  Further, the position conversion processing unit 25 calculates the difference between the phase measured by the phase detector 23 a and the phase measured by the phase detector 23 b and collates this phase difference with the phase difference stored in the memory 27. Thus, it is a processing device such as a CPU that performs processing for converting the calculated phase difference into a specific position in a two-dimensional space.

  Subsequently, a position specifying method using the transceiver 30b and the transmitters A and B according to the present embodiment will be described.

  As shown in FIGS. 10 and 11, a person who wears the wearable computer 1 and the transceiver 3 in a state where the transmitters A and B are installed and driven on the electric field transmission sheet 302 is moved to a specific position on the electric field transmission sheet 302. Touch α. Thereby, the receiving electrode 105b receives the electric fields from the transmitters A and B through the finger (living body 100) and the insulating film 107b. In the electric field detection optical device 115, the received electric field is coupled (applied) to an electro-optic crystal (not shown) in the electric field detection optical device 115, converted into an electric signal, and then transmitted to the signal processing circuit 116. The amplification unit 114 of the signal processing circuit 116 amplifies the electric signal and transmits it to the bandpass filter 151. However, the electric signal related to the electric field from the transmitters A and B does not pass through the band pass filter 151.

  The electrical signal transmitted from the amplifying unit 114 is also transmitted to the bandpass filters 11a and 11b.

  In the band pass filter 11a, the signal component of only the band (fa) for the transmitter A among the electric signals related to the electric field from the transmitters A and B is transmitted and transmitted to the phase detector 23a. The phase detector 23a detects the phase of the electrical signal related to the signal component passed by the bandpass filter 11a.

  On the other hand, in the band pass filter 11b, among the electric signals related to the electric fields from the transmitters A and B, the signal component of only the band (fb) for the transmitter B is passed and transmitted to the phase detector 23b. The phase detector 23b detects the phase of the electrical signal related to the signal component passed by the bandpass filter 11b.

  Next, the position conversion processing unit 25 calculates the difference between the phase measured by the phase detector 23 a and the phase measured by the phase detector 23 b and collates this phase difference with the phase difference stored in the memory 27. As a result, the calculated phase difference is converted into the specific position α in the two-dimensional space on the electric field transmission sheet 302.

  Finally, the position information (data) of the specific position α obtained by the position conversion processing unit 25 is transmitted from the position conversion processing unit 25 to the wearable computer 1 via the I / O circuit 101.

  As described above, according to the present embodiment, the same effects as those of the first embodiment can be obtained.

  Hereinafter, specific examples of the first and second embodiments will be described with reference to FIGS. 15 to 17.

<First specific example>
15 and 16 show examples in which the above embodiments are used for the electric field transmission sheet 302a and a keyboard for a personal computer. As shown in FIG. 15, by printing a picture of the keyboard on the electric field transmission sheet 302a, for example, when a person touches the specific position α1, the touch is made from the distances x1 and y1 from the transmitters A and B, respectively. The key can be specified.

  As described above, the wearable computer 1 sends position information, in this case, the distances x1 and y1 from the transmitters A and B in this case. A correspondence table of position information vs. input information, which is the same as the relationship between the position on the sheet 302a and the print information at that position, is provided, so that the wearable computer 1 can grasp information intended by a human.

<Second specific example>
FIG. 17 shows an example in which each of the above embodiments is used for an electric field transmission sheet 302b such as a touch panel, a touch screen, or a showcase. Similarly, in this case, for example, when a person touches the specific position α2, the touched position can be specified from the distances x2 and y2 from the transmitters A and B, respectively.

  In the above-described embodiment, “two transmitters” and “electric field transmission sheet” are used, and the electric signal from the two transmitters is received by hand (finger) by touching the electric field transmission sheet with a hand (finger). To the transceiver via the living body 100), and the transceiver separates the two electrical signals, and based on the two electrical signals, obtains the distance information from the two transmitters of the touched position. However, the gist of the present invention is not limited to this.

  For example, it can be applied not only to a two-dimensional plane but also to a three-dimensional space. In other words, if “three transmitters” and a three-dimensional “electric field transmission medium” are used, a signal is transmitted through the electric field transmission medium from the three transmitters to a finger pointing to a certain point in the three dimensions. Then the transceiver will separate the three signals. As a result, the transceiver can acquire the position information of the point in the three-dimensional space intended by the human. Furthermore, if this is sent to an information device such as a wearable computer, the intended information can be input to the information device by a person pointing to a certain point in the three-dimensional space.

  Further, if the processing speed of the transceiver is sufficient, the transceiver can grasp the information on the position of the finger or the like as the information on the movement of the finger or the like. That is, for example, by tracing the electric field transmission sheet with a finger, the transceiver can grasp the movement of the finger in real time, and if the information is sent to an information device such as a wearable computer, the movement information itself or Information related to the motion information intended by humans can be input to the information device.

  Furthermore, the information sent to the transceiver via the living body is not limited to a signal that can acquire the position (velocity). For example, if the electric field transmission sheet has a function of detecting pressure, the pressure signal can also be converted into an electric field and sent to the transceiver via a finger or the like. In other words, in this case, the transceiver can acquire information on the pressing force intended by a human, and if this information is further sent to an information device such as a wearable computer, the information device can obtain information corresponding to the pressing force. It can be acquired.

  In the above description, the information device such as the wearable computer has been described as having information corresponding to the position information and pressure information intended by humans, but the transceiver itself has this information. In this case, the transceiver itself can acquire information intended by humans. Alternatively, a third device other than an information device such as a wearable computer and a transceiver may have the information, and the information device and the transceiver may acquire the information from the third device.

  Next, an embodiment related to a transceiver when a light intensity modulator is employed in the electric field detection optical unit will be described.

<Third Embodiment>
Hereinafter, the electric field detection optical device 115a according to the third embodiment of the present invention and a light intensity modulation type transceiver (hereinafter simply referred to as “transceiver”) including the electric field detection optical device 115a will be described with reference to FIGS. ) 3 will be described.

  FIG. 18 is an overall configuration diagram of a transceiver body 30c used for performing data communication via a human body (living body 100). FIG. 18 is an overall configuration diagram common to the third to seventh embodiments.

  As shown in FIG. 18, the transceiver body 30c includes an I / O (input / output) circuit 101, a transmission unit 103, a transmission electrode 105a, a reception electrode 105b, insulating films 107a and 107b, an electric field detection optical device 115 (an electric field detection optical unit). 110, light receiving circuit 152), signal processing circuit 116, and waveform shaping circuit 117.

  The I / O circuit 101 is a circuit in which the transceiver body 3c inputs and outputs information (data) with an external device such as the wearable computer 1. The transmission unit 103 is configured by a transmission circuit that induces an electric field related to this information in the living body 100 based on information (data) output from the I / O circuit 101. The transmission electrode 105a is an electrode used for inducing an electric field with respect to the living body 100 by the transmission unit 103, and is used as a transmission antenna. The receiving electrode 105b receives an electric field induced and transmitted to the living body 100 from the wearable computer 1, the transceiver 3 ′, the PC 5 and the transceivers 3′a and 3′b attached to other parts of the living body 100. It is an electrode used for this purpose, and is also used as a receiving antenna.

  The insulating film 107 a is an insulating film disposed between the transmission electrode 105 a and the living body 100 and plays a role of preventing the transmitting electrode 105 a from directly contacting the living body 100. The insulating film 107 b is an insulating film disposed between the receiving electrode 105 b and the living body 100 and plays a role of preventing the receiving electrode 105 b from directly contacting the living body 100.

  Furthermore, the electric field detection optical unit 110 constituting the electric field detection optical device 115 has a function of causing the laser light to change its light intensity by applying (applying) the electric field received by the receiving electrode 105b to the laser light. .

  The light receiving circuit 152 constituting the electric field detecting optical device 115 is a circuit that receives the laser light whose light intensity has been changed and converts it into an electric signal and performs signal processing such as amplification of the electric signal. The signal processing circuit 116 includes at least a band-pass filter. By this band-pass filter, the frequency components other than the frequency component related to the reception information that is the target of electric field detection among the electric signals of various frequencies. By removing (that is, extracting only the frequency component related to the received information), signal processing such as removal of noise from the electrical signal is performed.

  The waveform shaping circuit 117 is a circuit that performs waveform shaping (signal processing) on the electrical signal transmitted from the signal processing circuit 116 and supplies the waveform to the wearable computer 1 via the I / O circuit 101.

  Next, the electric field detection optical device 115a according to the third embodiment, which is an example of the electric field detection optical device 115, will be described in more detail with reference to FIG. The electric field detection optical device 115a according to the present embodiment includes an electric field detection optical unit 110a that is an example of the electric field detection optical unit 110 and a light receiving circuit 152a that is an example of the light receiving circuit 152. The electric field detection optical device 115 a is installed in a transceiver body 30 c that is an example of the transceiver body 30.

  The electric field detection optical unit 110a according to this embodiment includes a current source 119, a laser diode 121, a collimator lens 133, a beam splitter 139, a light intensity modulator 124, and first and second condenser lenses 141a and 141b. Yes.

  Among these, the light intensity modulator 124 is configured such that the light intensity of the light passing therethrough varies depending on the electric field intensity to be coupled. A first electrode 125 and a second electrode 127 are provided on both side surfaces of the light intensity modulator 124 facing in the vertical direction in the drawing. The first electrode 125 and the second electrode 127 sandwich the traveling direction of the laser light from the laser diode 121 in the light intensity modulator 124 from both sides, and can couple the electric field to the laser light at a right angle.

  In addition, the electric field detection optical unit 110a is connected to the reception electrode 105b through the first electrode 125. The second electrode 127 facing the first electrode 125 is connected to the ground electrode 131 and is configured to function as a ground electrode with respect to the first electrode 125. When the receiving electrode 105b detects an electric field transmitted by being induced in the living body 100, the receiving electrode 105b can transmit the electric field to the first electrode 125 and be coupled to the light intensity modulator 124 via the first electrode 125. it can.

  The laser light output from the laser diode 121 by the current control of the current source 119 is converted into parallel light through the collimator lens 133, and the laser light that has become parallel light enters the beam splitter 139. The beam splitter 139 is an optical system that divides incident laser light into two and emits it. Of the laser beams branched by the beam splitter 139, the first laser beam is incident on the first condenser lens 141a via the light intensity modulator 124. The second laser beam branched by the beam splitter 139 is incident on the second condenser lens 141 b without passing through the light intensity modulator 124.

  On the other hand, the light receiving circuit 152a is reverse to the first photodiode 143a that converts it into a current signal according to the light intensity of the first laser light modulated by the light intensity modulator 124. A first set of a first constant voltage source 147a that provides a bias voltage, a first load resistor 145a that converts a current signal converted by the first photodiode 143a into a voltage signal, and a second condenser lens 141b. A second photodiode 143b that converts it into a current signal according to the light intensity of the second laser light received in this way, a second constant voltage source 147b that applies a reverse bias voltage to the second photodiode 143b, and a second A second set comprising a second load resistor 145b for converting the current signal converted by the photodiode 143b into a voltage signal. It is equipped with a door.

  As a result, the first laser light that has passed through the light intensity modulator 124 and the first condenser lens 141a of the electric field detection optical unit 110a is received by the first photodiode 143a, and the result is obtained by the first combination. A voltage signal (with signal component) is output. Further, the second laser light that has passed through the second condenser lens 141b of the electric field detection optical unit 110a is received by the second photodiode 143b, and as a result, the noise (( Outputs a voltage signal (no signal component) containing noise.

  The light receiving circuit 152a also includes a differential amplifier 112 that differentially amplifies the voltage signal converted by the first load resistor 145a and the voltage signal converted by the second load resistor 145b. Differential amplification is performed, and this output is supplied to the signal processing circuit 116 shown in FIG.

  As described above, according to the present embodiment, the laser light (signal) that branches the laser light immediately before the laser light is incident on the light intensity modulator 124 and inputs one to the light intensity modulator 124 to detect the electric field. The other is used as laser light (no signal component) for removing noise of the laser light without being input to the light intensity modulator 124. For this reason, even when a light intensity modulator 124 that cannot extract an intensity modulation signal differentially, such as a modulator that converts the polarization change of laser light into an intensity change such as the polarization modulator 123, noise of the laser light is used. Can be removed.

<Fourth Embodiment>
Hereinafter, the electric field detection optical device 115b according to the fourth embodiment of the present invention and the light intensity modulation type transceiver 3 including the electric field detection optical device 115b will be described with reference to FIG.

  The electric field detection optical device 115b according to this embodiment includes an electric field detection optical unit 110b described below in place of the electric field detection optical unit 110a in the electric field detection optical device 115a according to the third embodiment. Of the configuration of the electric field detection optical unit 110b, the same configuration as the configuration of the electric field detection optical unit 110a is denoted by the same reference numeral, and the description thereof is omitted. In addition, since the light receiving circuit 152a of the present embodiment has the same configuration as the light receiving circuit 152a according to the first embodiment, description thereof is omitted.

  As shown in FIG. 20, in the electric field detection optical unit 110b of this embodiment, the first optical variable attenuator 134A is inserted and installed between the beam splitter 139 and the light intensity modulator 124, and the beam splitter 139 and the second condenser lens are inserted. The second optical variable attenuator 134B is inserted and installed between 141b. The first and second optical variable attenuators 134A and B attenuate the light intensity of the laser light by a predetermined ratio.

  However, since the first laser light branched into two by the beam splitter 139 passes through the light intensity modulator 124, the second laser light does not pass through the light intensity modulator 124. Since the transmission efficiency of the second laser beam is higher than the transmission efficiency of light, it is necessary to balance both. Therefore, in the present embodiment, the attenuation amount of the second optical variable attenuator 134B through which the second laser light passes is set larger than the attenuation amount of the first optical variable attenuator 134A through which the first laser light passes. .

  As a result, the first optical variable attenuator 134A can attenuate the light intensity of the first laser beam branched by the beam splitter 139 and then convert it into a current signal by the first photodiode 143a. The light intensity of the second laser beam branched by the beam splitter 139 can be attenuated by the attenuator 134B and then converted into a current signal by the second photodiode 143b. Moreover, the rate of attenuation is greater for the laser light passing through the second optical variable attenuator 134B than for the laser light passing through the first optical variable attenuator 134A.

  As described above, according to the present embodiment, even if the laser beam is branched in order to remove the noise of the laser beam by inserting and installing the first and second optical variable attenuators 134A and B, the difference is obtained. The input signal to the dynamic amplifier 112 can be balanced.

  If the input signal to the differential amplifier 112 can be balanced only by the second optical variable attenuator 134B, the first optical variable attenuator 134A may be omitted without being attached.

<Fifth Embodiment>
Hereinafter, the electric field detection optical device 115c according to the fifth embodiment of the present invention and the light intensity modulation type transceiver 3 including the electric field detection optical device 115c will be described with reference to FIG.

  The electric field detection optical device 115c according to this embodiment includes a light reception circuit 152b described below instead of the light reception circuit 152a in the electric field detection optical device 115a according to the third embodiment. Note that, among the configurations of the light receiving circuit 152b, the same components as those of the light receiving circuit 152a are denoted by the same reference numerals, and the description thereof is omitted. In addition, since the electric field detection optical unit 110a of the present embodiment has the same configuration as the electric field detection optical unit 110a according to the first embodiment, description thereof is omitted.

  As shown in FIG. 21, in place of the first and second load resistors 145a and 145b of the third embodiment, the light receiving circuit 152b of the present embodiment is provided with first and second variable load resistors 145A and 145B, respectively. The point is the feature. The first and second variable load resistors 145A and 145B have variable load resistance values, and the resistance value of the second variable load resistor 145B is larger than the resistance value of the first variable load resistor 145A. Is set.

  Thereby, the signal intensity of the output voltage signal from the first photodiode 143a and the second photodiode 143b can be made the same.

  As described above, according to the present embodiment, instead of the first and second load resistors 145a and 145b of the first embodiment, in the light receiving circuit 152b of the present embodiment, the first and second variable load resistors 145A. , B, the input signal to the differential amplifier 112 can be balanced even when the laser beam is branched in order to remove the noise of the laser beam.

  Note that if only one of the first and second variable load resistors 145A and 145B can balance the input signal to the differential amplifier 112, either one may be omitted without being attached.

<Sixth Embodiment>
Hereinafter, the electric field detection optical device 115d according to the sixth embodiment of the present invention and the light intensity modulation type transceiver 3 including the electric field detection optical device 115d will be described with reference to FIG.

  The electric field detection optical device 115d according to this embodiment includes a light reception circuit 152c described below instead of the light reception circuit 152a in the electric field detection optical device 115a according to the third embodiment. Note that, among the configurations of the light receiving circuit 152c, the same components as those of the light receiving circuit 152a are denoted by the same reference numerals, and description thereof is omitted. In addition, since the electric field detection optical unit 110a of the present embodiment has the same configuration as the electric field detection optical unit 110a according to the first embodiment, description thereof is omitted.

  As shown in FIG. 22, in place of the first and second constant voltage sources 147a and 147b of the third embodiment, the light receiving circuit 152c of the present embodiment includes first and second variable voltage sources 147A and 147B, respectively. The point provided is a feature. The first and second variable voltage sources 147A and B have variable voltage values, and are set so that the voltage value of the second variable voltage source 145B is smaller than the voltage value of the first variable voltage source 147A. Has been.

  Thereby, the signal intensity of the output voltage signal from the first photodiode 143a and the second photodiode 143b can be made the same.

  As described above, according to this embodiment, instead of the first and second constant voltage sources 147a and 147b of the third embodiment, the light receiving circuit 152c of this embodiment has the first and second variable voltages, respectively. By providing the sources 147A and 147B, it is possible to balance the input signal to the differential amplifier 112 even when the laser light is branched in order to remove noise of the laser light.

  If the input signal to the differential amplifier 112 can be balanced by only one of the first and second variable voltage sources 147A and 147B, either one may be omitted without being attached.

<Seventh Embodiment>
Hereinafter, the electric field detection optical device 115e according to the seventh embodiment of the present invention and the light intensity modulation type transceiver 3 including the electric field detection optical device 115e will be described with reference to FIG.

  The electric field detection optical device 115e according to this embodiment includes a light reception circuit 152d described below instead of the light reception circuit 152a in the electric field detection optical device 115a according to the third embodiment. Of the components of the light receiving circuit 152d, the same components as those of the light receiving circuit 152a are designated by the same reference numerals, and the description thereof is omitted. In addition, since the electric field detection optical unit 110a of the present embodiment has the same configuration as the electric field detection optical unit 110a according to the first embodiment, description thereof is omitted.

  As shown in FIG. 23, before the output voltage signals from the first and second photodiodes 143a and 143b are input to the differential amplifier 112, the first and second variable for amplifying the respective voltage signals. A feature is that the gain amplifiers 149A and 149B are provided. The first and second variable gain amplifiers 149A and 149B are variable in voltage gain, and are set so that the voltage gain of the second variable gain amplifier 149B is smaller than the voltage gain of the first variable gain amplifier 149A. Has been.

  Thereby, even if the signal strengths of the output voltage signals from the first photodiode 143a and the second photodiode 143b are different, they can be made the same.

  As described above, according to the present embodiment, before the output voltage signals from the first and second photodiodes 143a and 143b are input to the differential amplifier 112, the first voltage signals are amplified. By providing the first and second variable gain amplifiers 149A and 149B, it is possible to balance the input signals to the differential amplifier 112 even when the laser light is branched in order to remove the noise of the laser light.

  If only one of the first and second variable gain amplifiers 149A and 149B can balance the input signal to the differential amplifier 112, either one may be omitted without being attached.

  As the light intensity modulators in the third to seventh embodiments described above, electroabsorption (EA) light intensity modulators, Mach-Zehnder light intensity modulators, and the like can be employed as in the prior art.

<Eighth Embodiment>
The transceiver body 30d of the transceiver according to the eighth embodiment of the present invention will be described below using FIG.

  The transceiver body 30d according to the present embodiment has an overall configuration as shown in FIG. Of the overall configuration, the components other than the electric field detection optical device 215, the noise detection unit 218, and the control signal generation unit 219 are the same as those of the transceiver main body 30c according to the third embodiment, and are therefore denoted by the same reference numerals. The description is omitted.

  In the transceiver main body 30d of the present embodiment, any of the electric field detection optical devices 115b to 115e described in the fourth to seventh embodiments is used as the electric field detection optical device 215, and the voltage output from the signal processing circuit 116 is used. A noise detection unit 218 that detects the magnitude of a noise component of the signal, and an electric field detection optical unit 110 and a light receiving circuit that constitute the electric field detection optical device 215 based on detection data output from the noise detection unit 218 A feature is that a control signal generator 219 for generating a control signal for variably controlling the variable value in 152 is provided. The noise detection unit 218 indicates how much noise remains in the electrical signal output from the signal processing circuit 116, that is, how much noise exists in the frequency band related to the reception information that is the electric field detection target. Detect if there is.

  Here, the “variable value” indicates the attenuation amount of the light intensity of the first and second optical variable attenuators 134A and B in the fourth embodiment (FIG. 20). In the fifth embodiment (FIG. 21), the resistance values of the first and second variable load resistors 145A and 145B are shown. In the sixth embodiment (FIG. 22), the voltage values of the first and second variable voltage sources 147A, B are shown. In the seventh embodiment (FIG. 23), voltage gains of the first and second variable gain amplifiers 113A and 113B are shown.

  As described above, according to this embodiment, even after the transceiver body 30d is manufactured, there is an effect that the variable value can be automatically changed and adjusted.

  Next, a transceiver comprising a transceiver body capable of transmitting and receiving information via an electric field transmission medium, a battery that drives the transceiver body, and an insulating case that covers the transceiver body, Of these, an embodiment related to a transceiver of a type in which a wide area is contacted with a living body (hand) as an electric field transmission medium will be described.

  First, the focus of the embodiment of the transceiver will be described. Therefore, regarding the transceiver and wearable computer shown in FIG. 9, consider an equivalent circuit between a living body (hand), a transmission / reception electrode, a transceiver body, and a battery.

  FIG. 25 is a diagram illustrating an equivalent circuit between a living body, a transmission / reception electrode, and a transceiver body.

  In FIG. 9, since the living body 100 and the transmission / reception electrode 105 'are separated by an insulating film 107', the impedance between the living body 100 and the transmission / reception electrode 105 can be expressed by an equivalent circuit as shown in FIG.

  By the way, in order to realize highly reliable communication through the living body 100, it is necessary to increase the induced AC electric field (frequency f) to the living body 100. In order to increase the induced AC electric field (frequency f), it is necessary to reduce the impedance between the living body 100 and the transmission / reception electrode 105. Here, as shown in FIG. 25, since the resistance component of the impedance between the living body 100 and the transmission / reception circuit 105 is considered to be very large, in order to reduce the impedance, it is necessary to increase the capacitance component.

  Therefore, in order to increase the capacitance component, it is effective to use a material having a large dielectric constant as the material of the insulating film 107 or to reduce its thickness. In addition, it is effective to increase the area of the transmission / reception electrode 105 so as to be widely opposed to the indirectly opposed living body.

  However, if the thickness of the insulating film 107 is too thin, there is a high possibility that the living body 100 directly touches the transmission / reception electrode 105, and the risk of a large current flowing through the living body 100 increases. Therefore, the measure to increase the area of the transmission / reception electrode 105 is advantageous because the capacitance can be increased while ensuring safety. Further, a shielding effect can be expected by increasing the size of the transmission / reception electrode 105.

  FIG. 26 is a diagram illustrating an equivalent circuit between the living body, the transceiver body, and the battery.

  In order to achieve highly reliable communication through the living body 100, it is necessary to prevent an unnecessary alternating electric field (frequency f) from being induced between the living body 100, the transceiver body 30, and the battery 6. For this purpose, it is necessary to increase the impedance between them and reduce the mutual coupling capacity.

  Therefore, in order to further increase the effect of interposing an insulator between each other, an insulator having a small dielectric constant is used, or the insulator, the living body 100, the transceiver main body 30, and the battery 6 are used. It is necessary to reduce the contact area with each of them and to increase the thickness of the insulator.

  From the above viewpoint, in the transceiver of the type shown in FIG. 9, the following can be considered as an embodiment for performing reliable and reliable communication via a living body.

<Ninth Embodiment>
Hereinafter, the ninth embodiment will be described with reference to FIGS. 27 to 30.

  FIG. 27 is an overall configuration diagram of the transceiver 3a and the wearable computer 1 according to the ninth embodiment. FIG. 28 is a functional block diagram mainly showing functions of the transceiver main body 30. FIG. 29 is a detailed configuration diagram of the electric field detection optical device 115 ′. FIG. 30 is a usage image diagram showing a usage state of the transceiver 3a and the wearable computer 1 shown in FIG.

  As shown in FIG. 27, the transceiver 3 a includes an insulating case 33 formed of an insulator, the following devices incorporated in the insulating case 33, and the following attached to the outside of the insulating case 33. It is comprised by the member etc.

  An insulating foam material 7 a for weakening the electrical coupling between the insulating case 33 and the transceiver body 30 is attached to the bottom of the inner wall surface of the insulating case 33. A transceiver body 30 for transmitting / receiving data (information) to / from the wearable computer 1 is attached to the upper surface. Further, an insulating foam 7b for weakening the electrical coupling between the transceiver main body 30 and the battery 6 is attached to the upper surface. Further, a battery 6 for driving the transceiver 30 is attached to the upper surface. That is, the insulating foam material 7 a is sandwiched (supported in a sandwiched state) between the insulating case 33 and the transceiver body 30, and the insulating foam material 7 b is sandwiched between the transceiver body 30 and the battery 6. Further, the insulating foam materials 7a and 7b are provided with holes containing innumerable air. For this reason, noise transmission between the insulating case 33 and the transceiver body 30 can be suppressed by the insulating foam material 7a. Further, the transmission of noise between the transceiver body 30 and the battery 6 can be suppressed by the insulating foam material 7b.

  Further, a first ground electrode 131 (described later) is extended from the transceiver main body 30 so as not to contact other devices (battery 6, wearable computer 1, etc.) and to be insulated from the transmission / reception electrode 105. The case 33 is attached to the upper part of the inner wall surface. In addition, a second ground electrode 161 and a third ground electrode 163, which will be described later, extend from the transceiver body 30 and are not in contact with other devices (battery 6, wearable computer 1, etc.) and the first ground electrode 131. Moreover, it is attached to the upper part of the inner wall surface of the insulating case 33 that is away from the transmitting / receiving electrode 105.

  The transmission / reception electrode 105 is attached to the bottom of the outer wall surface and the side of the outer wall surface of the insulating case 33, and the entire transmission / reception electrode 105 is covered with the insulating film 107. Note that portions other than the operation / input surface of the wearable computer 1 are covered with an insulating case 11.

  Further, the transceiver body 30 includes an I / O (input / output) circuit 101, a transmission unit 103, a transmission / reception electrode 105, an insulating film 107, an electric field detection optical device 115 ′, a reception circuit 113 (a signal processing circuit 116, a waveform shaping circuit 117). However, these configurations will be described again.

  The I / O circuit 101 is a circuit in which the transceiver body 30 inputs and outputs information (data) with an external device such as the wearable computer 1. The transmission unit 103 is configured by a transmission circuit that induces an electric field related to this information in the living body 100 based on information (data) output from the I / O circuit 101. The transmission / reception electrode 105 is an electrode used for inducing an electric field to the living body 100 by the transmission unit 103 and is used as a transmission antenna. The transmitting / receiving electrode 105 is an electrode used for receiving an electric field induced and transmitted by the living body 100, and is also used as a receiving antenna. The insulating film 107 is an insulating film disposed between the transmitting / receiving electrode 105 and the living body 100, and plays a role of preventing the transmitting / receiving electrode 105 from directly contacting the living body 100.

  Furthermore, the electric field detection optical device 115 ′ has a function of detecting an electric field received by the transmission / reception electrode 105 and converting the electric field into an electric signal as reception information.

  Further, the signal processing circuit 116 of the receiving circuit 113 further amplifies the electric signal transmitted from the electric field detection optical unit 115 ′ and limits the band of the electric signal to remove unnecessary noise and unnecessary signal components. It is a circuit which performs the process to perform.

  The waveform shaping circuit 117 is a circuit that performs waveform shaping (signal processing) on the electrical signal transmitted from the signal processing circuit 116 and supplies the waveform to the wearable computer 1 via the I / O circuit 101. Note that the transmission unit 103, the reception circuit 113, and the I / O circuit 101 can be driven by the battery 6.

  Here, the electric field detection optical unit 115 ′ will be described in detail with reference to FIG. 29. Although the outline has been described with reference to FIG. 4, it will be described again.

  The electric field detection optical unit 115 ′ performs processing for returning the electric field received by the transceiver body 30 to an electric signal. This process is performed by detecting an electric field by an electro-optic technique using laser light and an electro-optic crystal.

  As shown in FIG. 29, the electric field detection optical unit 115 ′ includes a current source 119, a laser diode 121, an electro-optic element (electro-optic crystal) 123, first and second wavelength plates 135 and 137, a polarization beam splitter 139, and a plurality of pieces. Lens 133, 141a, b, photodiode 143a, b, and first ground electrode 131.

  Among these, the electro-optical element 123 has sensitivity only to an electric field coupled in a direction perpendicular to the traveling direction of the laser light from the laser diode 121, and the optical characteristics, that is, the birefringence index changes depending on the electric field strength. The polarization of the laser beam is changed by changing the birefringence. A first electrode 125 and a second electrode 127 are provided on both side surfaces of the electro-optic element 123 facing each other in the vertical direction on FIG. The first electrode 125 and the second electrode 127 sandwich the traveling direction of the laser light from the laser diode 121 in the electro-optic element 123 from both sides, and can couple the electric field to the laser light at a right angle.

  The electric field detection optical unit 115 ′ is connected to the transmission / reception electrode 105 through the first electrode 125. The second electrode 127 facing the first electrode 125 is connected to the first ground electrode 131 and is configured to function as a ground electrode with respect to the first electrode 125. The transmission / reception electrode 105 can receive an electric field that is induced and transmitted to the living body 100, transmit the electric field to the first electrode 125, and can be coupled to the electro-optic element 123 via the first electrode 125. .

  On the other hand, the laser light output from the laser diode 121 by the current control of the current source 119 is converted into parallel light through the collimator lens 133, and the polarization state of the laser light that has become parallel light is adjusted by the first wavelength plate 135. Then, the light enters the electro-optical element 123. The laser light incident on the electro-optical element 123 propagates between the first and second electrodes 125 and 127 in the electro-optical element 123. During the propagation of the laser light, the transmission / reception electrode 105 is placed on the living body as described above. When an electric field induced and transmitted by 100 is received and this electric field is coupled to the electro-optical element 123 via the first electrode 125, the electric field is connected to the ground electrode 131 from the first electrode 125. It is formed toward the second electrode 127. Since this electric field is perpendicular to the traveling direction of the laser light incident on the electro-optic element 123 from the laser diode 121, the birefringence, which is the optical characteristic of the electro-optic element 123, changes, thereby changing the polarization of the laser light. To do.

  Next, the laser light whose polarization has been changed by the electric field from the first electrode 125 in the electro-optic element 123 is adjusted in polarization state by the second wave plate 137 and is incident on the polarization beam splitter 139. The polarization beam splitter 139 separates the laser light incident from the second wave plate 137 into P waves and S waves, and converts them into changes in light intensity.

  The laser beams separated into the P wave component and the S wave component by the polarization beam splitter 139 are condensed by the first and second condenser lenses 141a and 141b, respectively, and then the first and second photodiodes 143a. , 143b, and the first and second photodiodes 143a, 143b can convert the P-wave optical signal and the S-wave optical signal into respective current signals and output them. As described above, the current signals output from the first and second photodiodes 143a and 143b are converted into voltage signals using resistors, and then amplified and removed by the signal processing circuit 116 shown in FIG. The signal processing is applied.

  Furthermore, in the transceiver body 30 of the present embodiment, the first ground electrode 131 serving as a voltage reference point for the electric field detection optical unit 115 ′ is extended to the outside of the transceiver body 30 as shown in FIG. . In addition, the second ground electrode 161 serving as the voltage reference point for the signal processing circuit 116 and the third ground electrode 163 serving as the voltage reference point for the transmission unit 103 are commonly extended to the outside. Yes.

  Next, using states of the transceiver 3a and the wearable computer 1 according to the present embodiment will be described with reference to FIG.

  As shown in FIG. 30, when the transceiver 3 a is held by a human hand (living body 100), the insulating case 33 has the outer wall bottom and the outer wall side. Even in such a case, since the transmission / reception electrode 105 and the insulating film 107 cover not only the bottom of the outer wall surface of the insulating case 33 but also the side of the outer wall surface, the electric field E1 for transmission is transmitted from the entire insulating case 33. Although E2 and E3 are induced, a part of the electric field is prevented from returning from the hand to the transceiver 3 through the side surface of the insulating case 33.

  As described above, according to the present embodiment, not only the bottom surface (bottom portion) but also the wide surface including the side surface (side portion) among the outer wall surfaces of the insulating case 33 are used for transmitting electrodes (here, transmission and reception). Since the electrode 105) is attached and covered with the insulating film 107, even if the transceiver 3a is held by a human hand, a part of the electric field for transmission can be prevented from returning to the transceiver 3a again from the hand. .

  In addition, the first ground electrode 131, the second ground electrode 161, and the third ground electrode 163 are attached to the upper part of the inner wall surface of the insulating case 33 and away from the transmission / reception electrode 105. It is possible to prevent unnecessary signals from wrapping around the transceiver body 30 and to strengthen the ground.

  Further, since the insulating foam material 7 a is sandwiched between the insulating case 33 and the transceiver body 30, and further, the insulating foam material 7 b is sandwiched between the transceiver body 30 and the battery 6. Therefore, it is possible to suppress the noise that enters the transceiver body 30.

<Tenth Embodiment>
Hereinafter, the tenth embodiment will be described with reference to FIG.

  FIG. 31 is an overall configuration diagram of the transceiver 32 and the wearable computer 1 according to the tenth embodiment. Note that the same components as those in the ninth embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In the present embodiment, as shown in FIG. 31, insulative support columns 99a and 99b are employed instead of the insulative foaming agents 7a and 7b of the ninth embodiment.

  As described above, according to the present embodiment, since the contact area between the insulator and each of the living body 100, the transceiver body 30, and the battery 6 is reduced, the effect that the unnecessary AC electric field is not induced is further increased.

  In addition to the foaming agent, wood may be used as the material of the insulating support columns 99a and 99b. However, light and durable materials such as paulownia are preferred.

  Moreover, although the support | pillar was employ | adopted in this embodiment, you may make it have a block structure.

<Eleventh embodiment>
The eleventh embodiment will be described below using FIG.

  FIG. 32 is an overall configuration diagram of the transceiver 3c and the wearable computer 1 according to the eleventh embodiment. Note that the same components as those in the ninth embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In the present embodiment, as shown in FIG. 32, the second and third ground electrodes 161 and 163 are extended from the insulating case 33 of the transceiver 3 c and are provided on the side surface (side portion) of the insulating case 11 of the wearable computer 1. It is attached.

  Thus, according to the present embodiment, in addition to the effects of the ninth embodiment, the second and third ground electrodes 161 and 163 are further separated from the transmission / reception electrode 105 as compared with the ninth embodiment. Therefore, it is possible to prevent the unnecessary signal from wrapping from the transmission / reception electrode 105 to the transceiver body 30 more firmly, and to further strengthen the ground.

<Twelfth Embodiment>
The twelfth embodiment will be described below using FIG.

  FIG. 33 is an overall configuration diagram of the transceiver 3d and the wearable computer 1 according to the twelfth embodiment. Note that the same components as those in the ninth embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In the present embodiment, as shown in FIG. 33, the first ground electrode 131 extends from the insulating case 33 of the transceiver 3 d and is attached to the side surface (side part) of the insulating case 11 of the wearable computer 1.

  As described above, according to the present embodiment, in addition to the effects of the ninth embodiment, the first ground electrode 131 is further away from the transmission / reception electrode 105 as compared with the ninth embodiment. The unnecessary signal from the electrode 105 to the transceiver body 30 can be more securely prevented and the ground can be further strengthened.

<13th Embodiment>
The thirteenth embodiment will be described below using FIG.

  FIG. 34 is an overall configuration diagram of the transceiver 3e and the wearable computer 1 according to the thirteenth embodiment. Note that the same components as those in the ninth embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In the present embodiment, as shown in FIG. 34, the transmission / reception electrode 105 is divided into a transmission electrode 105a dedicated for transmission and a reception electrode 105b dedicated for reception, and the transmission electrode 105a is arranged in the portion of the transmission / reception electrode 105 shown in FIG. As shown in FIG. 34, the receiving electrode 105b is disposed on the outer bottom surface of the insulating film 107a. The receiving electrode 105b is also covered with an insulating film 107b so that the human body is not directly touched. In this embodiment, the insulating film 107 shown in FIG. 31 is represented as an insulating film 107a.

  Thus, according to the present embodiment, in addition to the effects of the ninth embodiment, the transmission electrode 105a is relatively large and covers almost the entire insulating case 33, and the reception electrode 105b is small. Therefore, there is also an effect that the rate at which part of the electric field for transmission returns from the hand is reduced.

  Note that, as in the transceiver 3f shown in FIG. 35, the arrangement positions of the transmission electrode 105a and the reception electrode 105b may be switched (14th embodiment).

<Other embodiments>
In the eleventh and twelfth embodiments, one of the ground electrodes is attached to the side surface of the insulating case 11 of the wearable computer 1, but the present invention is not limited to this, and the first ground electrode 131 and the second and third grounds are not limited thereto. You may attach to the side surface of the insulation case 11 of the wearable computer 1, respectively, without making both the electrodes 161 and 163 contact.

  In the ninth and eleventh to thirteenth embodiments, the insulating foam 7 a is sandwiched between the insulating case 33 and the transceiver body 30, and the insulating foam 7 b is sandwiched between the transceiver body 30 and the battery 6. However, the present invention is not limited to this, and as shown in FIG. 36, an integral insulating foam material 8 that covers the battery 6 and the transceiver body 30 without contacting them may be used. Furthermore, as shown in FIG. 37, a cushion-like insulating material 9 in which a gas such as air is confined may be used instead of the foamed material.

It is an image figure in the case of performing communication between several wearable computers via a human body. It is a whole block diagram of the conventional transceiver main body. It is a whole block diagram of the other conventional transceiver main body. It is a detailed block diagram of the electric field detection optical part and light receiving circuit of the conventional (polarization modulation type) transceiver body. FIG. 5 is a diagram showing a waveform of an input signal of the differential amplifier shown in FIG. 4. It is a detailed block diagram of the electric field detection optical part and light receiving circuit of the conventional (light intensity modulation type) transceiver body. It is a principle figure in case the light intensity modulator used with the electric field detection optical part of the conventional (light intensity modulation type) transceiver main body is an electro-absorption type. It is a principle figure in case the light intensity modulator used in the electric field detection optical part of the conventional (light intensity modulation type) transceiver body is a Mach-Zehnder type. It is the image figure which showed those usage conditions when it has a pair of a transceiver and a wearable computer with a human hand. It is the image figure of the front which showed the use condition of the transceiver and wearable computer concerning a 1st embodiment of the present invention. It is the image figure of the plane which showed the use condition of the transceiver and wearable computer which concern on the 1st Embodiment of this invention. It is the figure which showed the frequency band for information communication, the transmitter A, and the transmitter B. It is a whole lineblock diagram of a transceiver main part in a transceiver concerning a 1st embodiment. It is a whole block diagram of the transceiver main body in the transceiver which concerns on 2nd Embodiment. It is the figure which showed the specific example of the electric field transmission sheet which concerns on 1st and 2nd embodiment. It is the figure which showed the specific example of the electric field transmission sheet which concerns on 1st and 2nd embodiment. It is the figure which showed the specific example of the electric field transmission sheet which concerns on 1st and 2nd embodiment. It is a whole block diagram of the transceiver main body which concerns on the 3rd-7th embodiment of this invention. It is a detailed block diagram of the electric field detection optical part and light receiving circuit of the transceiver main body which concerns on 3rd Embodiment. It is a detailed block diagram of the electric field detection optical part and light receiving circuit of the transceiver main body which concerns on 4th Embodiment. It is a detailed block diagram of the electric field detection optical part and light receiving circuit of the transceiver main body which concerns on 5th Embodiment. It is a detailed block diagram of the electric field detection optical part and light receiving circuit of the transceiver main body which concerns on 6th Embodiment. It is a detailed block diagram of the electric field detection optical part and light receiving circuit of the transceiver main body which concerns on 7th Embodiment. It is a whole block diagram of the transceiver main body which concerns on the 8th Embodiment of this invention. It is a figure which shows the equivalent circuit between a biological body, a transmission / reception electrode, and a transceiver main body. It is a figure which shows the equivalent circuit between a biological body, a transceiver main body, and a battery. It is a whole block diagram of the transceiver and wearable computer which concern on the 9th Embodiment of this invention. It is a functional block diagram which mainly showed the function of the transceiver main body. It is a detailed block diagram of an electric field detection optical apparatus. It is the usage image figure which showed the use condition of the transceiver and wearable computer which are shown in FIG. It is a whole block diagram of the transceiver and wearable computer which concern on the 10th Embodiment of this invention. It is a whole block diagram of the transceiver and wearable computer which concern on the 11th Embodiment of this invention. It is a whole block diagram of the transceiver and wearable computer which concern on the 12th Embodiment of this invention. It is a whole block diagram of the transceiver and wearable computer which concern on the 13th Embodiment of this invention. It is a whole block diagram of the transceiver and wearable computer which concern on the 14th Embodiment of this invention. It is the figure which showed other embodiment of this invention. It is the figure which showed other embodiment of this invention.

Explanation of symbols

1 Wearable computer 3 ', 3, 3a-3e Transceiver 5 PC
6 Battery 7a, 7b Insulating foaming agent 30 ', 30, 30a-30f Transceiver body 33 Insulating case 99a, 99b Insulating support column 100 Living body 131 First ground 161 Second ground 163 Third ground 101 I / O circuit 103 Transmitter 113 Reception circuits 105 ′, 105 Transmission / reception electrodes 105′a, 105a Transmission electrodes 105′b, 105b Reception electrodes 107 ′, 107 Insulating films 115 ′, 115, 115a to 115e, 215 Electric field detection optical device 117 Waveform shaping circuit 116 Signal processing Circuits 11a, 11b, 151 Bandpass filters 13a, 13b Signal intensity measuring units 15, 25 Position conversion processing units 17, 27 Memory 114 Amplifying units 152, 152a to 152d Light receiving circuits 110 ′, 110′a, 110 Electric field detection optical unit 123 Polarization modulator 124 Light intensity modulator 124 Electroabsorption optical intensity modulator 124b Mach-Zehnder optical intensity modulator 125 First electrode 127 Second electrode 134A First variable optical attenuator 134B Second variable optical attenuator 139 ', 139 Polarizing beam splitter 143 Photodiode 143a First photodiode 143b second photodiode 147 constant voltage source 147a first constant voltage source 147b second constant voltage source 147A first variable voltage source 147B second variable voltage source 112 differential amplifier 118 amplifier 218 noise detector 219 control signal generator 300 Table 301 Insulating sheets 302, 302a, 302b Electric field transmission sheet

Claims (5)

An electric field detection optical device for detecting the electric field by modulating the light intensity of laser light based on the electric field to be detected,
An electric field detection optical unit and a light receiving circuit;
The electric field detection optical unit is
Laser beam emitting means;
Branching means for branching the laser light emitted from the laser light emitting means into different first and second laser lights;
Light intensity modulation having a structure in which an electric field to be detected is coupled to an electro-optic crystal, and modulating the light intensity of the first laser light passing through the electro-optic crystal based on the coupled electric field Means,
An optical variable attenuator that attenuates the light intensity of the second laser beam branched by the branching means and corrects an unbalance with respect to the light intensity of the first laser light modulated by the light intensity modulating means; Have
The light receiving circuit is
First light / voltage conversion means for converting the light intensity of the first laser light modulated by the light intensity modulation means into a voltage signal;
Second light / voltage conversion means for converting the intensity of the second laser light attenuated by the optical variable attenuator into a voltage signal;
Differential amplification means for differentially amplifying the voltage signal converted by the first light / voltage conversion means and the voltage signal converted by the second light / voltage conversion means;
An electric field detection optical device comprising: An electric field detection optical device for detecting the electric field by modulating the light intensity of laser light based on the electric field to be detected,
An electric field detection optical unit and a light receiving circuit;
The electric field detection optical unit is
Laser beam emitting means;
Branching means for branching the laser light emitted from the laser light emitting means into different first and second laser lights;
Light intensity modulation having a structure in which an electric field to be detected is coupled to an electro-optic crystal, and modulating the light intensity of the first laser light passing through the electro-optic crystal based on the coupled electric field Means,
The light receiving circuit is
First light / current conversion means for converting the light intensity of the first laser light modulated by the light intensity modulation means into a current signal;
A first voltage source for applying a reverse bias voltage to the first light / current converting means;
A first load / resistance converter configured to convert a current signal converted by the first light / current conversion means into a voltage signal ;
Second light / current conversion means for converting the intensity of the second laser beam branched by the branching means into a current signal;
A second voltage source for applying a reverse bias voltage to the second light / current converting means;
A second load resistor for converting the current signal converted by the second light / current conversion means into a voltage signal; and a second light / voltage conversion means comprising:
Differential amplification means for differentially amplifying the voltage signal converted by the first light / voltage conversion means and the voltage signal converted by the second light / voltage conversion means;
At least one of the first load resistor and the second load resistor is a variable resistor. An electric field detection optical device for detecting the electric field by modulating the light intensity of laser light based on the electric field to be detected,
An electric field detection optical unit and a light receiving circuit;
The electric field detection optical unit is
Laser beam emitting means;
Branching means for branching the laser light emitted from the laser light emitting means into different first and second laser lights;
Light intensity modulation having a structure in which an electric field to be detected is coupled to an electro-optic crystal, and modulating the light intensity of the first laser light passing through the electro-optic crystal based on the coupled electric field Means,
The light receiving circuit is
First light / current conversion means for converting the light intensity of the first laser light modulated by the light intensity modulation means into a current signal;
A first voltage source for applying a reverse bias voltage to the first light / current converting means;
A first load / resistance converter configured to convert a current signal converted by the first light / current conversion means into a voltage signal ;
Second light / current conversion means for converting the intensity of the second laser beam branched by the branching means into a current signal;
A second voltage source for applying a reverse bias voltage to the second light / current converting means;
A second load resistor for converting the current signal converted by the second light / current conversion means into a voltage signal; and a second light / voltage conversion means comprising:
Differential amplification means for differentially amplifying the voltage signal converted by the first light / voltage conversion means and the voltage signal converted by the second light / voltage conversion means;
At least one of the first voltage source and the second voltage source is a variable voltage source. The light receiving circuit further includes variable amplification means for amplifying at least one of the voltage signal converted by the first light / voltage conversion means and the voltage signal converted by the second light / voltage conversion means. The electric field detection optical apparatus according to any one of claims 1 to 3. A transceiver capable of receiving information via the electric field transmission medium by receiving information based on an electric field induced in the electric field transmission medium,
The electric field detection optical device according to any one of claims 1 to 4,
A signal processing circuit for removing at least noise with respect to the voltage signal output from the electric field detection optical device;
Noise detecting means for detecting the magnitude of the noise component of the voltage signal output from the signal processing circuit;
The light attenuation amount of the optical variable attenuator in the electric field detection optical unit according to claim 1, based on detection data output from the noise detection unit, a resistance value of the variable resistor in the light receiving circuit according to claim 2, A control signal generator for generating a control signal for variably controlling the voltage value of the variable voltage source in the light receiving circuit according to claim 3 or the voltage amplification factor of the variable amplifying means according to claim 4;
A transceiver comprising:

Images