JP2003098205A - Field detecting optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a field detecting optical device used in a transceiver for a wearable computer without a wire, not radio-transmitting and basically independent of earth ground, and used for precisely performing data communication by an electric field. SOLUTION: The field induced and transmitted to a field transfer medium is connected to an electro-optic element 23 through a first electrode 25 to change the optical characteristic of the electro-optic element 23, whereby the polarization state of a laser beam entering the electro-optic element 23 changed in optical characteristic from a laser diode 21 is changed, the laser beam emitted from the electro-optic element is separated into P-wave and S-wave by a polarization beam splitter 39 to be converted to the intensity change of light, and the P-wave and S-wave are converted to electric signals by a first and second photodiodes 43a, 43b and outputted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transceiver used for data communication between wearable computers (computers worn on the body). The present invention relates to an electric field detection optical device that detects an incoming electric field and converts it into an electric signal.

[0002]

2. Description of the Related Art Wearable computers have been attracting attention due to the miniaturization and higher performance of portable terminals. FIG. 7 shows an example in which such a wearable computer is worn by a person and used. As shown in the figure, the wearable computer 1 is mounted on a human arm, shoulder, torso, etc. through the transceiver 3 to transmit and receive data to and from each other, and further, the transceivers 3a and 3b attached to the tips of the limbs are attached. Communication is performed via a cable with a personal computer (PC) 5 provided outside via the cable.

A data communication method between wearable computers is very important for putting such wearable computers into practical use. Conventionally, such data communication between wearable computers is performed as described above. A method of performing wired communication by connecting two transceivers connected to 1 with a data line and a ground line, a method of wirelessly connecting transceivers by wireless communication, and a method of using a living body as a signal line Using the earth ground that is in contact with as a ground line 2
Method to send and receive data over a line (PAN: Personal Are
a Network, IBMSYSTEMS JOURNAL, Vol.35, NOS, 3 & 4, pp.609
-See 617, 1996).

[0004]

Among the above-mentioned conventional techniques, the wired communication method requires that two transceivers be connected by an electric wire, so that data transmission between separate wearable computers or a plurality of wearable computers is not possible. When transmitting and receiving, there is a problem that it is not practical because the electric wire has to be routed around the body.

Further, the wireless communication method has a problem that it may interfere with other nearby systems depending on the radio frequency and power.

[0006] Furthermore, it is considered that most wearable computers are generally attached to the upper half of the body as a communication method using a living body as a signal path. For example, a transceiver of the wearable computer is placed on the head away from the ground. In this case, communication becomes impossible, which poses a serious problem in practical use.

The present invention has been made in view of the above,
Its purpose is to use for transceivers for wearable computers that do not require electric wires, are not wireless, and basically do not depend on the ground, and perform data communication properly using electric fields. An object of the present invention is to provide an electric field detection optical device used for this purpose.

[0008]

In order to achieve the above object, the present invention according to claim 1 is an electric field detecting optical device for detecting an electric field induced and transmitted in an electric field transmitting medium and converting the electric field into an electric signal. A light source for generating light of a single wavelength, a collimator lens for collimating the light from the light source, and the parallel light from the collimator lens,
And an electro-optical element whose optical characteristics change in response to an electric field to be coupled, a first electrode for coupling the electric field induced in the electric field transmission medium to the electro-optical element, and the electro-optical element. An analyzer that separates the parallel light into P waves and S waves and converts the parallel light into changes in light intensity, and a first converter that converts at least one of the P waves and S waves separated by the analyzer into an electrical signal. Opto-electrical conversion means, and the first electrode is disposed on one of opposite side surfaces of the electro-optical element positioned so as to sandwich the parallel light traveling in the electro-optical element. Use as a summary.

According to the first aspect of the present invention, the electric field induced and transmitted in the electric field transmission medium is coupled to the electro-optical element via the first electrode and is parallel to the electro-optical element. Light is made incident, and collimated light emitted from this electro-optical element is separated into P wave and S wave by an analyzer and converted into a change in light intensity, and at least one of P wave and S wave is converted into an electric signal. By applying it to a transceiver for wearable computers, for example, communication that does not use electric wires as in the past, communication that does not interfere with other systems by wireless, and communication that does not depend on the ground ground can be accurately performed between wearable computers. Can be done.

According to a second aspect of the present invention, there is provided an electric field detection optical device for detecting an electric field induced and transmitted in an electric field transmission medium and converting the electric field into an electric signal, which generates light of a single wavelength. Light source, a collimator lens that collimates the light from the light source, and the parallel light from the collimator lens is incident, multiple-reflected and emitted, and the optical characteristics change in response to the combined electric field. An electro-optical element, a first electrode for coupling an electric field induced in the electric field transmitting medium to the electro-optical element, and the parallel light emitted from the electro-optical element is separated into a P wave and an S wave. And a first photoelectric conversion means for converting at least one of the P wave and the S wave separated by the analyzer into an electric signal. The electrode is the electro-optical element In the subject matter to be placed on one of the opposite sides of the electro-optical element positioned so as to sandwich the parallel light that is multiple reflection.

According to a second aspect of the present invention, the electric field induced and transmitted in the electric field transmitting medium is coupled to the electro-optical element through the first electrode and is parallel to the electro-optical element. Light is made incident and multiple reflection is performed, and the parallel light emitted from this electro-optical element is separated into P wave and S wave by an analyzer and converted into intensity change of light, and at least one of P wave and S wave is converted. Since it is converted into an electrical signal and output, it can be applied to, for example, a transceiver for a wearable computer so that it can be used for communication that does not use electric wires as in the past, communication that does not interfere with other systems by wireless, and communication that does not depend on the ground. It can be performed accurately between computers, and since parallel light is reflected multiple times inside the electro-optical element, the optical path length affected by the electric field becomes long, and laser light Received many polarization change, it is possible to obtain a large signal, sufficient sensitivity can be obtained even if the electro-optical element in small size, and size and cost of the apparatus.

Further, the present invention according to claim 3 is the same as claim 1
Or the first wave plate provided between the collimator lens and the electro-optical element to adjust the polarization state of the parallel light from the collimator lens to enter the electro-optical element. A second electrode that is provided on the other of the opposite side surfaces of the optical element and functions as a ground electrode with respect to the first electrode, is provided between the electro-optical element and the analyzer, and A second wave plate that adjusts the polarization state of the transmitted parallel light and enters the analyzer, and a second optoelectric device that converts the other of the P wave and the S wave separated by the analyzer into an electric signal. The gist is to further include at least one or more of the conversion elements.

According to a fourth aspect of the present invention, in the invention according to the second aspect, the parallel light is multiply reflected in the electro-optical element by being provided on both side surfaces of the electro-optical element facing each other in the incident direction of the parallel light. The gist is to further include first and second reflective films for

According to a fifth aspect of the present invention, there is provided an electric field detection optical device for detecting an electric field induced and transmitted in an electric field transmission medium and converting the electric field into an electric signal, which generates light of a single wavelength. Light source, a collimator lens for collimating the light from the light source into parallel light, an electro-optical element which changes the optical characteristics in response to an electric field to which the parallel light is incident from the collimator lens and is coupled, A reflection film provided on the other end face of the optical element facing the end face on which the parallel light enters, and a reflection film for reflecting the parallel light, and a first for coupling an electric field induced in the electric field transmission medium to the electro-optical element. No. 1 electrode, and between the collimator lens and the electro-optical element, the parallel light from the collimator lens passes through and enters the electro-optical element, is reflected by the reflective film, and enters from the electro-optical element. The P-wave parallel light emitted in direction and S
An isolator that separates into waves and converts it into a change in light intensity,
A first photoelectric conversion means for converting at least one of the P wave and the S wave separated by the isolator into an electric signal, wherein the first electrode is parallel to the inside of the electro-optical element. The gist is that it is arranged on one of the opposite side surfaces of the electro-optical element positioned so as to sandwich light.

According to a fifth aspect of the present invention, the electric field induced and transmitted in the electric field transmitting medium is coupled to the electro-optical element via the first electrode and is parallel to the electro-optical element. Light is incident, reflected by a reflection film and emitted, and collimated light emitted from this electro-optical element is separated into a P wave and an S wave by an isolator and converted into a change in light intensity. Since one of them is converted into an electrical signal and output, by applying it to a transceiver for a wearable computer, for example, communication that does not use electric wires as in the past, communication that does not interfere with other systems by wireless, communication that does not depend on the ground Can be performed accurately between wearable computers, and since parallel light is reflected inside the electro-optical element, the optical path length affected by the electric field becomes longer. Received many polarization change laser beam,
A large signal can be obtained, sufficient sensitivity can be obtained even if the electro-optical element is downsized, and the device can be downsized and the cost can be reduced.

Further, the present invention according to claim 6 provides the invention according to claim 5.
In the invention described above, a second electrode that is provided on the other of the opposite side surfaces of the electro-optical element and functions as a ground electrode with respect to the first electrode, a P wave and an S wave separated by the isolator. It further has at least one or more of a second photoelectric conversion element for converting the other of them into an electric signal and a wave plate provided between the isolator and the electro-optical element for adjusting the polarization state of parallel light. That is the summary.

According to a seventh aspect of the present invention, in the invention according to the fifth aspect, the isolator allows the parallel light from the collimating lens to pass therethrough and also generates the P wave or the S wave from the reflected light from the electro-optical element. A first analyzer that separates and converts it into a change in the intensity of light; a wave plate that adjusts the polarization state of the parallel light from the collimator lens that has passed through the first analyzer and the reflected light from the electro-optical element; A Faraday element that rotates the polarization plane of the parallel light whose polarization state is adjusted by the wave plate and the reflected light from the electro-optical element, and the parallel light from the Faraday element that is provided between the Faraday element and the electro-optical element. And a second analyzer that separates the S wave or the P wave from the reflected light from the electro-optical element and converts it into a change in light intensity.

The present invention according to claim 8 is any one of claims 1 to 4.
Alternatively, in the present invention according to any one of claims 7 to 10, the analyzer or the first and second analyzers is
The gist is that it is a polarization beam splitter.

Furthermore, the present invention according to claim 9 is the same as claim 1.
In the invention described in any one of 1 to 8, it is preferable that two non-opposing side surfaces of the electro-optical element have an inclined portion formed by being obliquely processed with respect to a traveling direction of the parallel light. And

According to a tenth aspect of the present invention, in the present invention according to any one of the first to ninth aspects, the electro-optical element has an electric field in a direction perpendicular to a traveling direction of the parallel light, or substantially the same. The gist is that the optical characteristics change in response to an electric field in the perpendicular direction.

The present invention according to claim 11 is the invention according to any one of claims 1 to 10, wherein the light source is a light emitting diode which emits light of a single wavelength or a laser which emits laser light. The main point is that it is a light source.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the configuration of an electric field detection optical device according to the first embodiment of the present invention. In order to enable the electric field detection optical device 11 shown in the same figure to wear the wearable computer 1 on the living body 100 which is an electric field transmission medium as shown in FIG. 6, to enable data communication with other wearable computers and data communication devices. It is used as the electric field detection optical unit 110 in the transceiver 3 used.

Specifically, the transceiver 3 shown in FIG.
Is for inducing an electric field in the living body 100 based on transmission data input from the wearable computer 1, and transmitting and receiving data using the induced electric field. Input / output (I / I) of transmission data from the wearable computer 1 is performed.
O) When received via the circuit 101, this transmission data is supplied to the transmission electrode 105 via the transmission circuit 103, an electric field is induced in the living body 100 via the transmission electrode 105, and this electric field is transmitted via the living body 100. The information is transmitted to other parts of the living body 100.

Further, in the transceiver 3 shown in FIG. 6, the receiving electrode 107 detects an electric field which is induced in the living body 100 and transmitted from another transceiver mounted on another part of the living body 100, and this electric field is detected. It is coupled to the electric field detection optical unit 110 and converted into an electric signal. This electric signal is subjected to signal processing such as amplification, noise removal, and waveform shaping in the signal processing circuit 109, and is output to the wearable computer 1 via the input / output circuit 101.

In the transceiver 3 described above, FIG.
The electric field detection optical device 11 according to the first embodiment of the present invention shown in FIG.
The electric field detection optical unit 110 configured from detects an electric field that is induced and transmitted to the living body 100 and is coupled through the receiving electrode 107, converts the electric field into an electric signal, and converts the electric signal.
It functions to output to 9.

When the wearable computer 1 is attached to a living body as shown in FIG. 7 by using the transceiver 3 having the electric field detecting optical unit 110, the transceiver 3 is transferred to the living body based on the transmission information from the wearable computer 1. An electric field is induced and transmitted to the transceiver 3 of the other party as shown by a wavy line with an arrow in FIG. 7, whereby each wearable computer 1 performs data communication via the transceiver 3. Further, in FIG. 7, the transceivers 3 a and 3 b provided at the hands and feet are connected to the wearable computer 1 via another transceiver 3.
When the electric field transmitted from the computer is detected, the electric field is converted into an electric signal, transmitted to the personal computer (PC) 5 via the cable, and the transmission information received from the personal computer 5 via the cable is induced as an electric field in the living body. Then, the signal is transmitted to another transceiver 3.

Next, referring to FIG. 1, the first part of the electric field detecting optical section 110 used in the transceiver 3 of FIG.
The electric field detection optical device 11 of the embodiment will be described in detail.

An electric field detecting optical device 11 shown in FIG. 1 detects an electric field by an electro-optical method using a laser beam and an electro-optical crystal, and is composed of a laser diode 21 and an electro-optical crystal which constitute a laser light source. It has an electro-optical element 23. The electro-optical element 23 of the present embodiment
Has a sensitivity only to an electric field coupled in a direction perpendicular to the traveling direction of the laser light from the laser diode 21, and the optical characteristic, that is, the birefringence is changed by the electric field strength, and the birefringence is changed. Due to this, the polarization of the laser light is changed. In the present embodiment, the laser light output from the laser diode 21 is used.
The present invention is not limited to laser light, and may be any one that can generate a single wavelength light, such as a light emitting diode (L
ED), which is applicable to all other embodiments described later.

The electro-optical element 23 preferably has, for example, a prism shape, but is not limited to the prism shape, and may have another shape such as a cylinder shape.

First and second electrodes 25 and 27 are provided on both side surfaces of the electro-optical element 23 which face each other in the vertical direction in the figure. The first and second electrodes 25, 2
As will be described later, 7 is configured to sandwich the traveling direction of the laser light from the laser diode 21 in the electro-optical element 23 from both sides and couple the electric field to the laser light at a right angle.

The electric field detecting optical device 11 has a signal electrode 29 constituting the receiving electrode 107 shown in FIG. 6, and the signal electrode 29 is connected to the first electrode 25. Further, the second electrode 27 facing the first electrode 25 is connected to the ground electrode 31 and is configured to function as a ground electrode for the first electrode 25. In addition,
The ground electrode 31 functions as a ground by being connected to, for example, the battery of the transceiver 3 or connecting to a large metal or the like, and improves the coupling of the electric field from the first electrode 25 to the electro-optical element 23. However, the ground electrode 31 is not always necessary. This is applicable to all the other embodiments described later.

The signal electrode 29 is the receiving electrode 10 shown in FIG.
When the electric field induced and transmitted in the living body 100 is detected, this electric field is transmitted to the first electrode 25, and the electro-optical element 2 is transmitted through the first electrode 25.
It is designed to combine with 3.

The laser light output from the laser diode 21 is collimated through the collimator lens 33,
The polarization state of the laser light that has become parallel light is adjusted by the first wave plate 35 and is incident on the electro-optical element 23. The laser light incident on the electro-optical element 23 propagates between the first and second electrodes 25 and 27 in the electro-optical element 23, and during the propagation of the laser light, the signal electrode 29 is generated as described above. When the electric field induced and transmitted to the living body 100 is detected and the electric field is coupled to the electro-optical element 23 via the first electrode 25, the electric field is connected from the first electrode 25 to the ground electrode 31. The laser diode 21 formed toward the second electrode 27 that is formed.
Since it is perpendicular to the traveling direction of the laser light incident on the electro-optical element 23, the birefringence, which is an optical characteristic of the electro-optical element 23, changes as described above, and thereby the polarization of the laser light changes.

Thus, in the electro-optical element 23, the first
The laser light whose polarization is changed by the electric field from the electrode 25 of which the polarization state is adjusted by the second wave plate 37 enters the polarization beam splitter 39. Polarizing beam splitter 3
Reference numeral 9 denotes an analyzer, which is also called a polarizer or a polarizer, separates the laser light incident from the second wave plate 37 into P-waves and S-waves and converts them into intensity changes of light. . The laser beams separated into the P-wave component and the S-wave component by the polarization beam splitter 39 are first and
After being condensed by the second condenser lenses 41a and 41b, the light is supplied to the first and second photodiodes 43a and 43b which constitute the photoelectric conversion means, and the first and second photodiodes 43a and 43b The P-wave optical signal and the S-wave optical signal are converted into respective electric signals and output. In the above embodiment, the polarization beam splitter 3
The P-wave component and the S-wave component separated by 9 are both converted into electric signals by the first and second photodiodes 43a and 43b, and are output.
Only one of the first and second photodiodes 43a and 43b and the first and second condenser lenses 41a and 41b is provided, and only one of the P wave component and the S wave component is converted into an electric signal. Can be output. This is applicable to all the other embodiments described later.

As described above, the electric signals output from the first and second photodiodes 43a and 43b are subjected to signal processing such as amplification, noise removal and waveform shaping in the signal processing circuit 109 shown in FIG. Is supplied to the wearable computer 1 via the input / output circuit 101.

Next, an electric field detecting optical device according to the second embodiment of the present invention will be described with reference to FIG.

The electric field detecting optical device 12 shown in FIG.
In the electric field detection optical device 11 shown in FIG.
The two different side surfaces 23a and 23b that do not face each other are obliquely processed with respect to the traveling direction of the laser beam to form an inclined portion, and the other configurations and operations are the same.

When the electric field is applied to the electro-optical element 23, a phenomenon called an inverse piezoelectric effect occurs in which a crystal forming the electro-optical element 23 is physically distorted. The polarization due to the inverse piezoelectric effect changes the polarization of the laser light, but this change is usually small. However, if the electric field changes at a certain frequency,
The physical distortion of the electro-optical element 23 also changes with frequency, and when this change resonates with the distance of the facing surface of the crystal, a great effect occurs and the polarization change becomes extremely large. When such resonance occurs, the waveform is distorted and a communication error occurs.

Therefore, in the electric field detecting optical device 12 of the second embodiment shown in FIG. 2, in order to prevent the resonance due to such an inverse piezoelectric effect, the electro-optical element 23 does not face each other.
The two side surfaces 23a and 23b are obliquely processed so that resonance does not occur. The oblique angle with respect to the traveling direction of the laser light is 0.5 ° to 1.0 °.
Is preferred. Thus, the side surface 23 of the electro-optical element 23
By diagonally machining a and 23b to prevent resonance,
The frequency characteristic can be flattened, and it is possible to appropriately prevent the occurrence of a communication error due to the waveform being distorted.

Next, an electric field detecting optical device according to the third embodiment of the present invention will be described with reference to FIG.

The electric field detecting optical device 13 of the third embodiment shown in FIG. 3 has a laser diode 21 and an electro-optical element 23 like the electric field detecting optical device 11 of the first embodiment shown in FIG. Although the electric field is detected by the electro-optical method, the electric field detecting optical device 11 of FIG. 1 is of a type in which the laser light is transmitted through the electro-optical element 23. The electric field detection optical device 13 is provided with a reflection film 51 on the end surface opposite to the end surface of the electro-optical element 23 on which the laser light from the laser diode 21 is incident, whereby the laser light that has proceeded into the electro-optical element 23 is reflected by the reflection film 5.
1 is different from the electric field detection optical device 11 in FIG. 1 in that the reflection type electric field detection optical device is reflected by 1 and emitted from the incident end surface.

That is, the electric field detecting optical device 13 of the third embodiment shown in FIG. 3 is provided on the opposite side surfaces of the collimating lens 33 and the electro-optical element 23, which collimate the laser light from the laser diode 21 into parallel light. The first and second electrodes 25 and 27, the signal electrode 29 and the ground electrode 31 connected to the first and second electrodes 25 and 27, and the first and second electrodes for condensing the P wave component and the S wave component of the laser light. The first and second condensing lenses 41a and 41b, and the first and second P-wave optical signals and the S-wave optical signals condensed by the first and second condensing lenses 41a and 41b are converted into electric signals, respectively. It is the same as the electric field detection optical device 11 shown in FIG. 1 in that it has the photodiodes 43a and 43b.

In addition to these components, the electric field detecting optical device 13 shown in FIG. 3 is provided between the collimating lens 33 and the electro-optical element 23, and the laser light incident from the collimating lens 33 is applied to the electro-optical element 23. Is an isolator 61 that separates the laser light, which is reflected by the reflection film 51 of the electro-optical element 23 and is returned to the P-wave and the S-wave, and converts it into a change in the intensity of the light. A beam splitter 53, a first wave plate 55 including a λ / 2 wave plate, an Faraday element 57, an isolator 61 including a second polarization beam splitter 59, and a second wave plate 63 for adjusting the polarization state of laser light. Further has.

The first polarization beam splitter 53 which constitutes the isolator 61 allows the laser light from the collimator lens 33 to pass therethrough, and separates the P or S wave from the reflected light from the electro-optical element 23 so that the intensity of the light is increased. The first wavelength plate 55, which is converted into a change and enters the first condensing lens 41a, and which constitutes a λ / 2 wavelength plate, receives the laser light from the collimator lens 33 that has passed through the first polarization beam splitter 53 and the electric power. The Faraday element 57 adjusts the polarization state of the reflected light from the optical element 23, and the Faraday element 57 rotates the polarization planes of the laser light whose polarization state is adjusted by the first wave plate 55 and the reflected light from the electro-optical element 23. The second polarization beam splitter 59 allows the laser light from the Faraday element 57 to pass through the electro-optical element, and at the same time reflects the reflected light from the electro-optical element 23 into an S wave or To be incident on the second condensing lens 41b converts the intensity change of the light separates the P-wave.

More specifically, the isolator 61 allows the laser light from the collimator lens 33 to pass therethrough, adjusts the polarization state of the laser light with the second wave plate 63, and causes the laser light to enter the electro-optical element 23. When the light propagates between the first and second electrodes 25 and 27 in the electro-optical element 23, the signal electrode 29 detects the electric field induced and transmitted by the living body 100, and this electric field is the first electric field. Assuming that the electric field is coupled to the electro-optical element 23 via the electrode 25, this electric field is formed from the first electrode 25 toward the second electrode 27 connected to the ground electrode 31, and the electric field is generated from the laser diode 21. Since the laser light incident on the element 23 is perpendicular to the traveling direction, the birefringence, which is an optical characteristic of the electro-optical element 23, changes, which changes the polarization of the laser light. The same applies when the laser light whose polarization state has changed passes through the electro-optical element 23 whose optical characteristics have been changed by the electric field to reach the reflection film 51, is reflected by the reflection film 51, and returns in the electro-optical element 23 in the opposite direction. The laser light whose polarization state has changed and which is emitted from the electro-optical element 23 enters the isolator 61 and is separated into P-waves and S-waves by the first and second polarization beam splitters 53 and 59 of the isolator 61. Is converted into an intensity change and emitted.

Thus, the first and second isolator 61 are
The P-wave component and S-wave component laser beams emitted from the polarization beam splitters 53 and 59, respectively, are condensed by the first and second condenser lenses 41a and 41b, and the first and second photodiodes 43a and 43a, 43b is made incident, converted into an electric signal and outputted.

In the present embodiment, the laser light is reflected by the reflection film 51 and reciprocates in the electro-optical element 23, so that the optical path length affected by the electric field becomes long, and the laser light undergoes many polarization changes and a large signal. Can be obtained. Therefore, even if the electro-optical element is downsized, sufficient sensitivity can be obtained, so that the size and cost of the device can be reduced.

Next, an electric field detecting optical device according to the fourth embodiment of the present invention will be described with reference to FIG.

The electric field detecting optical device 14 shown in FIG.
Similar to the embodiment of FIG. 2 for the embodiment of FIG. 2, in the electric field detection optical device 13 shown in FIG. And thus, the electro-optical element 2
The third configuration is the same as the third configuration except that the resonance due to the inverse piezoelectric effect of 3 is prevented, the frequency characteristics are flattened, and the waveform is distorted to prevent a communication error. . Note that, in FIG. 4, only the portion where the upper side surface of the electro-optical element 23 is obliquely processed is shown, but the non-opposing side surfaces adjacent to this upper side surface are also obliquely processed.

Next, an electric field detecting optical device according to the fifth embodiment of the present invention will be described with reference to FIG.

The electric field detecting optical device 15 of the fifth embodiment shown in FIG. 5 has a laser diode 21 and an electro-optical element 23 like the electric field detecting optical device 11 of the first embodiment shown in FIG. Although the electric field is detected by the electro-optical method in the same manner, the electric field detecting optical device 11 of FIG. 1 is of a type in which the laser light passes straight through the electro-optical element 23. The electric field detection optical device 15 shown in FIG. 5 is different from the electric field detection optical device 11 of FIG. 1 in that it is a multiple reflection transmission type electric field detection optical device through which laser light is transmitted while undergoing multiple reflection in the electro-optical element 23. The electro-optical element 23 has sensitivity to an electric field at right angles to the traveling direction of the laser light, and basically changes the optical characteristics depending on the strength of the combined electric field. The directions need not be exactly right angles, but may be substantially right angles as shown in FIG. 5, that is, they may be slightly deviated from right angles.

As described above, in order to multiple-reflect the laser light in the electro-optical element 23 and to couple the electric field almost at right angles to the traveling direction of the multiple-reflected laser light, the electric field detecting optical device 15 of FIG. Is the first and second reflection films 71 on the other side surfaces facing each other in the direction perpendicular to the facing direction of the facing side surfaces of the electro-optical element 23 provided with the first and second electrodes 25 and 27. , 73 are provided,
The laser light is multiply reflected between the first and second reflection films 71 and 73. The rest of the configuration is basically the same as that of the embodiment shown in FIG.

The laser light from the laser diode 21 is collimated by the collimator lens 33, and then,
The polarization state is adjusted by the first wave plate 35, and the first and second electrodes 2 are arranged between the second reflection film 73 and the first electrode 25.
The light is incident on the electro-optical element 23 toward the first reflection film 71 so as to be substantially perpendicular to the electric field between 5 and 27, and is reflected by the first reflection film 71 in a direction substantially perpendicular to the electric field. The reflected laser light is further reflected by the second reflection film 73 in a direction substantially perpendicular to the electric field, and is repeatedly reflected as shown in the figure. Finally, the second reflection film 73 and the second electrode 2 are repeatedly reflected.
Light is emitted from between 7 and the outside.

As described above, while the laser light is multiply reflected in the electro-optical element 23, the signal electrode 29 detects an electric field induced and transmitted to the living body 100, and the electric field is transmitted through the first electrode 25. When coupled to the electro-optical element 23, this electric field is formed from the first electrode 25 toward the second electrode 27 connected to the ground electrode 31,
Since the laser light is incident on the electro-optical element 23 from the laser diode 21 and is multiple-reflected at right angles to the multiple-reflecting direction, which is the traveling direction, the birefringence, which is an optical characteristic of the electro-optical element 23, changes, and as a result, The polarization of the reflected laser light changes.

The laser light emitted from the electro-optical element 23, whose polarization state is changed while undergoing multiple reflections in this way, is adjusted in polarization state by the second wave plate 37 and is incident on the polarization beam splitter 39. The polarization beam splitter 39 splits the laser light incident from the second wave plate 37 into P-waves and S-waves, and converts the laser light into intensity changes. The laser light separated into the P-wave component and the S-wave component is condensed by the first and second condenser lenses 41a and 41b, respectively, and then supplied to the first and second photodiodes 43a and 43b. The first and second photodiodes 43a and 43b convert the P-wave optical signal and the S-wave optical signal into respective electric signals and output the electric signals.

In this embodiment, the laser light is multiply reflected in the electro-optical element 23 and the optical path length affected by the electric field is long, and the laser light undergoes many polarization changes.
You can get a big signal. Therefore, even if the electro-optical element is downsized, sufficient sensitivity can be obtained, so that the size and cost of the device can be reduced.

In addition, for the electric field detecting optical device 15 of the embodiment shown in FIG. 5, two side surfaces of the electro-optical element 23 that do not face each other are irradiated with laser light as in the embodiments of FIGS. 2 and 4 described above. Of the electro-optical element 23 to prevent resonance due to the inverse piezoelectric effect, flatten the frequency characteristic, and distort the waveform to cause a communication error. It can also be configured to prevent.

[0058]

As described above, according to the present invention,
The electric field induced and transmitted in the electric field transmission medium is coupled to the electro-optical element via the first electrode, parallel light is made incident on the electro-optical element, and the P wave and S wave are separated by the analyzer. Since it is converted into a change in the intensity of light, and at least one of the P wave and the S wave is converted into an electric signal and then output, it can be applied to, for example, a transceiver for a wearable computer, so that an electric wire is not used unlike the prior art It is possible to appropriately perform communication, wireless communication without interference with other systems, and communication that does not depend on the ground, between wearable computers.

Further, according to the present invention, the electric field induced and transmitted in the electric field transmitting medium is coupled to the electro-optical element via the first electrode, and parallel light is incident on the electro-optical element. The parallel light emitted from this electro-optical element is separated into P waves and S waves and converted into a change in light intensity, and at least one of the P waves and S waves is converted into an electric signal. Since it is output as, by applying to a transceiver for wearable computer,
It is possible to accurately perform communication without using electric wires, wireless communication without interference with other systems, and communication that does not depend on the ground as between conventional wearable computers, as well as parallel light, as well as electro-optical elements. Since the light is reflected or multiple-reflected inside the optical path, the optical path length affected by the electric field becomes long, the laser light undergoes many polarization changes, and a large signal can be obtained. The sensitivity can be obtained, and the device can be downsized and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an electric field detection optical device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of an electric field detection optical device according to a second embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of an electric field detection optical device according to a third embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of an electric field detection optical device according to a fourth embodiment of the present invention.

FIG. 5 is a diagram showing a configuration of an electric field detection optical device according to a fifth embodiment of the present invention.

FIG. 6 is a block diagram showing a circuit configuration of a transceiver for mounting a wearable computer on a living body, to which the electric field detecting optical device of the present invention is applied.

FIG. 7 is an explanatory diagram showing an example of a case in which a wearable computer is attached to a human and used via a transceiver.

[Explanation of symbols]

1 wearable computer 3 transceivers 11, 12, 13, 14, 15 Electric field detection optical device 21 Laser diode 23 Electro-optical element 25,27 First and second electrodes 29 signal electrode 31 ground electrode 33 Collimating lens 35 First Wave Plate 37 Second Wave Plate 39 Polarizing beam splitter 41a, 41b First and second condenser lenses 43a, 43b First and second photodiodes 51 Reflective film 53 First Polarizing Beam Splitter 55 First Wave Plate (λ / 2 Wave Plate) 57 Faraday element 59 Second polarization beam splitter 61 Isolator 71, 73 First and second reflective films 100 living body 110 Electric field detection optical unit

Claims (11)

[Claims] 1. An electric field detection optical device for detecting an electric field induced and transmitted in an electric field transmission medium and converting the electric field into an electric signal, wherein the light source generates light of a single wavelength, and light from the light source. A collimating lens for converting the collimated light into parallel light, an electro-optical element that changes the optical characteristics in response to an electric field to which the parallel light from the collimator lens is incident and is coupled, A first electrode for coupling to the electro-optical element; an analyzer for separating the parallel light passing through the electro-optical element into P-waves and S-waves and converting the change into light intensity change; A first photoelectric conversion means for converting at least one of the P wave and the S wave separated into the electric signal into an electric signal, and the first electrode converts the parallel light propagating in the electro-optical element. The electricity located to sandwich Field detecting optical system, characterized in that disposed on one of opposite sides of the academic elements. 2. An electric field detection optical device for detecting an electric field induced and transmitted in an electric field transmission medium and converting the electric field into an electric signal, the light source generating light of a single wavelength, and the light from the light source. A collimating lens for converting the parallel light into parallel light, an electro-optical element that receives the parallel light from the collimator lens, multiple-reflects the parallel light, and outputs the parallel light, and changes the optical characteristics in response to an electric field to be coupled, A first electrode for coupling an electric field induced in a medium to the electro-optical element, and a detector for separating the parallel light emitted from the electro-optical element into P-waves and S-waves and converting the light into intensity changes. A photon and a first photoelectric conversion means for converting at least one of the P wave and the S wave separated by the analyzer into an electric signal; and the first electrode in the electro-optical element. Multiple reflections Field detecting optical system, characterized in that disposed on one of opposite sides of the electro-optical element positioned so as to sandwich the line light. 3. A first wave plate which is provided between the collimator lens and the electro-optical element, adjusts the polarization state of parallel light from the collimator lens and enters the electro-optical element, A second electrode that is provided on the other of the facing side surfaces and that functions as a ground electrode with respect to the first electrode, is provided between the electro-optical element and the analyzer, and is parallel to the electro-optical element. A second wave plate that adjusts the polarization state of light and enters the analyzer, and a second opto-electric conversion element that converts the other of the P wave and the S wave separated by the analyzer into an electric signal 3. The electric field detecting optical device according to claim 1, further comprising at least one of them. 4. Further comprising first and second reflecting films provided on both side surfaces of the electro-optical element facing each other in the incident direction of the parallel light, for multiple-reflecting the parallel light in the electro-optical element. The electric field detecting optical device according to claim 2, characterized in that: 5. An electric field detection optical device for detecting an electric field induced and transmitted in an electric field transmission medium and converting the electric field into an electric signal, wherein the light source emits light of a single wavelength, and light from the light source. Collimating lens for converting the collimated light into parallel light, an electro-optical element that receives the parallel light from the collimator lens, and changes optical characteristics in response to an electric field coupled thereto, and the parallel light of the electro-optical element enters A reflecting film provided on the other end face opposite to the end face, for reflecting the parallel light, a first electrode for coupling an electric field induced in the electric field transmitting medium to the electro-optical element, and the collimating lens. The collimated light from the collimator lens, which is provided between the electro-optical element and the collimator lens, is incident on the electro-optical element, reflected by the reflective film, and emitted from the electro-optical element in the incident direction. An isolator for separating the P wave and the S wave and converting into a change in light intensity, and a first photoelectric conversion means for converting at least one of the P wave and the S wave separated by the isolator into an electric signal are provided. The first electrode is arranged on one of opposite side surfaces of the electro-optical element that is positioned so as to sandwich the parallel light traveling in the electro-optical element. 6. A second electrode provided on the other of the facing side surfaces of the electro-optical element, the second electrode functioning as a ground electrode with respect to the first electrode, the P wave and the S wave separated by the isolator. A second opto-electrical conversion element for converting the other of the two into an electric signal, and at least one or more of a wave plate provided between the isolator and the electro-optical element for adjusting the polarization state of the parallel light. The electric field detection optical device according to claim 5, characterized in that it has. 7. The first analyzer, wherein the isolator allows the parallel light from the collimator lens to pass therethrough and separates the P wave or the S wave from the reflected light from the electro-optical element to convert it into a change in light intensity. A wavelength plate that adjusts the polarization states of the parallel light from the collimator lens that has passed through the first analyzer and the reflected light from the electro-optical element, and the parallel light and the electro-optic that have their polarization states adjusted by the wavelength plate. A Faraday element that rotates the plane of polarization of the reflected light from the element, and is provided between the Faraday element and the electro-optical element, allows parallel light from the Faraday element to pass through the electro-optical element, and reflects from the electro-optical element. S wave or P from light
The electric field detecting optical device according to claim 5, further comprising a second analyzer that separates a wave and converts the wave into a change in light intensity. 8. The electric field detection optics according to claim 1, wherein the analyzer or the first and second analyzers is a polarization beam splitter. apparatus. 9. The two side surfaces of the electro-optical element that do not face each other have an inclined portion formed by being obliquely processed with respect to the traveling direction of the parallel light.
9. The electric field detection optical device according to any one of items 8 to 8. 10. The electro-optical element according to claim 1, wherein the optical characteristics change in response to an electric field in a direction perpendicular to the traveling direction of the parallel light or an electric field in a direction substantially perpendicular to the traveling direction of the parallel light. The electric field detection optical device according to any one of claims. 11. The electric field detecting optical device according to claim 1, wherein the light source is a light emitting diode that emits light of a single wavelength or a laser light source that emits laser light. .