JP6678939B2 - Deformation-sensitive fabric incorporating optical fiber, and detection device using the same - Google Patents

Description

  The present invention relates to a deformation-sensitive fabric incorporating an optical fiber, and a detection device using the same.

  In recent years, there has been a demand for a sensor device capable of detecting the deformation of a surface to be measured such as the surface of human skin.

  Patent Document 1 discloses a garment in which an optical fiber is woven into a fabric. By monitoring the light loss due to the breakage of the optical fiber, it is possible to detect the damage caused to the clothes and thus the wearer of the clothes.

  Patent Document 2 discloses an optical fiber type flat plate sensor in which an optical fiber is fixed or mixed in a flat plate such as a sheet, a floor cloth, a blanket, and a mat. By measuring the polarization fluctuation in the optical fiber, the uneven deformation of the flat plate due to the force applied to the flat plate in the direction perpendicular to its surface is detected.

Japanese Patent Publication No. 2002-517301 JP, 2007-61306, A

  However, with the garment disclosed in Patent Document 1 above, damage to the garment due to breakage of the optical fiber can be detected, but deformation such as uneven deformation and elastic deformation of the garment cannot be detected.

  In the optical fiber type flat plate sensor disclosed in the above-mentioned Patent Document 2, the uneven deformation of the flat plate due to the force in the direction perpendicular to the plane of the flat plate can be detected, but the uneven deformation is accompanied. It is not possible to detect deformations on the surface to be measured, such as elastic deformations.

  The present invention has been made in view of such a background, and a deformation-sensitive fabric incorporating an optical fiber capable of appropriately detecting deformation such as uneven deformation and expansion / contraction deformation of a measurement target surface, and a detection device using the same. The purpose is to provide.

In order to achieve the above-mentioned object, a deformation-sensitive fabric incorporating the optical fiber according to the first aspect of the present invention comprises cores of different diameters and a clad provided on the outer periphery of the core, and a part of the transmitted light is transmitted. Having a leaking hetero core part , an optical fiber that is incident from the incident end and passes through the hetero core part and is emitted from the emission end, consists of a woven fabric or a knitted fabric produced by weaving or knitting with a yarn, and the hetero core part and The yarn intersecting the optical fiber having the hetero core portion is in contact, and the propagation light intensity of the optical fiber is changed according to the expansion and contraction deformation of the yarn contacting the optical fiber having the hetero core portion. And

  According to the deformation-sensitive fabric incorporating the optical fiber according to the first aspect of the present invention, since the light transmitting portion and the yarn are in contact with each other, it is possible to change the state depending on whether or not tension is applied to the yarn. As a result, the hardness of the thread changes, and the degree of curvature (curvature) of the light transmitting section changes accordingly. Therefore, it is possible to appropriately detect the deformation such as the uneven deformation and the elastic deformation of the surface of the measurement object which the woven or knitted fabric contacts.

  In addition, since it is made of a woven fabric or a knitted fabric produced by weaving or knitting the optical fiber together with a yarn, it becomes a cloth such as clothes like a normal woven fabric or a knitted fabric made of only the yarn, and the surface of a detection target such as a human body. Can be covered without being overly restrained.

A deformation-sensitive fabric incorporating the optical fiber according to the second invention of the present invention includes cores of different diameters and clads provided on the outer periphery of the cores, and a hetero-core portion that leaks a part of transmitted light. It is produced by weaving or knitting with an optical fiber built-in twisted yarn in which an optical fiber that is incident from the incident end and passed through the hetero core portion is emitted from the emission end and is twisted with a yarn, and a twisted yarn in which only the yarn is twisted or a yarn consists woven or knitted fabric, in the hetero-core portion and the twisting or projection space is projected in the direction of the yarn, the twisting or crossing the optical fiber built-twisting containing the optical fiber having the hetero-core portion and the hetero-core portion in contact the with yarn, the twisting or the light-off in response to the expansion and contraction deformation of the thread in contact with the optical fiber built-twister Iba built-twisting
It is characterized in that the propagation light intensity of the optical fiber included in (1) changes .

  According to the deformation-sensitive cloth incorporating the optical fiber according to the second aspect of the present invention, as in the deformation-sensitive cloth incorporating the optical fiber according to the first aspect of the present invention, the unevenness of the surface of the measuring object with which the woven or knitted fabric comes into contact It is possible to appropriately detect deformation such as deformation and expansion / contraction deformation, and it is possible to cover the surface of a detection target such as a human body without excessively restraining it as a cloth for clothes or the like.

  In the deformation-sensitive fabric incorporating the optical fiber according to the first or second invention of the present invention, it is preferable that the woven fabric or the knitted fabric is configured to be attached to a detection target.

  In this case, it becomes possible to easily attach the deformation-sensitive fabric incorporating the optical fiber to the detection target in a state of being in contact with the surface of the detection target.

Further, in the deformation-sensitive cloth incorporating the optical fiber according to the first or second invention of the present invention, the hetero core portion is arranged such that a direction orthogonal to a variation direction of the detection target is a longitudinal direction. Is preferred.

  In this case, it becomes possible to detect the deformation of the surface of the measurement target, which is in contact with the woven or knitted material, such as unevenness, expansion and contraction, with higher accuracy.

  Further, in the deformation-sensitive fabric incorporating the optical fiber according to the first or second invention of the present invention, it is preferable that the detection target is a human body and the woven or knitted fabric is configured like a garment.

  In this case, it becomes possible to easily attach the deformation-sensitive cloth incorporating the optical fiber to the detected person while being in contact with the surface of the detected person's skin.

  In addition, in the deformation-sensitive fabric incorporating the optical fiber according to the first or second invention of the present invention, it is preferable that a coating layer is provided on the surface of the woven fabric or the knitted fabric.

  In this case, if the coating layer is made of an appropriate material, the surface of the woven or knitted fabric can be improved in waterproofness, cleanability, strength and the like.

  A detection apparatus according to the present invention is a deformation-sensitive material incorporating the optical fiber according to the first or second invention of the present invention, a light source for outputting light incident on the optical fiber from the incident end, and an optical fiber for the optical fiber. And a photodetector for receiving the light emitted from the emission end.

  According to the detection device of the present invention, by using the deformation-sensitive cloth incorporating the optical fiber according to the first or second invention of the present invention having the above-described effects, the surface of the measurement object with which the cloth comes into contact It is possible to appropriately detect deformation such as uneven deformation and elastic deformation.

The photograph which shows the structure of the deformation-sensitive fabric which is the deformation-sensitive fabric which incorporated the optical fiber of 1st Embodiment of this invention, and its partial enlarged photograph. The schematic perspective view which shows the structure of a hetero core optical fiber. The schematic top view which shows the structure of a deformation sensitive textile. FIG. 4 is a schematic side view showing the deformation-sensitive fabric in a state where no tension is generated in the warp. FIG. 3 is a schematic side view showing a deformation-sensitive fabric in a state where tension is generated in a warp. The schematic diagram which shows the structure of a measurement system. The graph which shows the measurement data of the optical transmission characteristic of the optical fiber in the verification test of a pressure characteristic. The graph which shows the measurement data of the optical transmission characteristic of the optical fiber in the verification test of a bending characteristic. The graph which shows the measurement data of the optical transmission characteristic of the optical fiber in the verification test of the up-and-down expansion characteristic. The graph which shows the measurement data of the optical transmission characteristic of the optical fiber in the verification test of the expansion-contraction characteristic of a horizontal direction. The photograph which shows the mounting state of the deformation-sensitive fabric in the pulse measurement test. The graph which shows the measurement data of the optical transmission characteristic of the optical fiber in a pulse measurement test. The photograph which shows the mounting state of the deformation sensitive textile in the hand open / close measurement test. The graph which shows the measurement data of the optical transmission characteristic of the optical fiber in the hand open / close measurement test. The schematic side view which shows the deformation sensitive textiles which are the deformation sensitive textiles which incorporated the optical fiber of a 2nd embodiment of the present invention in the state where tension has not arisen in a warp. FIG. 3 is a schematic side view showing a deformation-sensitive fabric in a state where tension is generated in a warp. The graph which shows the measurement data of the optical transmission characteristic of the optical fiber in the verification test of expansion-contraction characteristic.

[First Embodiment]
A first embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the deformation-sensitive fabric incorporating the optical fiber of the present embodiment is configured as a deformation-sensitive fabric 100 including a fabric 3 in which the optical fiber 1 is woven together with the thread 2.

  In the present embodiment, as shown in FIG. 2, the optical fiber 1 is an optical fiber having a hetero core portion 1a corresponding to the light transmitting portion of the present invention having a predetermined length (for example, several mm) in the middle of its entire length. is there. The hetero core part 1a has a smaller diameter than the core 1b1 of each of the optical fibers 1b and 1b (hereinafter, the optical fiber 1b is referred to as a transmission line optical fiber 1b) that constitutes an optical transmission line connected to both sides in the axial direction. It is a part having 1a1.

  Incidentally, around the core 1a1 of the hetero core portion 1a and around the core 1b1 of each of the transmission line optical fibers 1b, claddings 1a2 and 1b2 having a constant outer diameter are formed, respectively, similarly to a normal optical fiber. . Further, the optical fiber forming the hetero core part 1a and each transmission line optical fiber 1b may be either a single mode optical fiber or a multimode optical fiber.

  As described above, the optical fiber 1 having the hetero core portion 1a (hereinafter referred to as the hetero core optical fiber 1) has, for example, a core diameter larger than that of the optical fiber forming the hetero core portion 1a on both end faces in the axial direction. It can be manufactured by splicing the transmission path optical fibers 1b and 1b having a large diameter to a coaxial core by fusion or the like.

  For example, by using a single mode fiber having a core diameter of 9 μm as the transmission path optical fiber 1b, cutting this, and inserting 2 mm of a single mode fiber having a core diameter of 5 μm as the hetero core portion 1a and fusing the connection portion, The hetero core optical fiber 1 may be manufactured.

  In such a hetero core optical fiber 1, when light is incident from the incident end which is one side of the transmission path optical fiber 1b, a part of the light that enters the hetero core portion 1a from the transmission path optical fiber 1b on the one side is , Is not transmitted to the transmission path optical fiber 1b on the other side through the core 1a1 of the hetero core portion 1a, and leaks to the outside of the hetero core portion 1a. The amount of light leakage in this case has a high correlation with the degree of curvature (average curvature) of the hetero core optical fiber 1 in the hetero core portion 1a, and the higher the degree of curvature, the greater the amount of light leakage (leak amount). Will increase.

  Therefore, when measuring the transmission loss of light in the hetero core optical fiber 1, the transmission loss increases as the degree of curvature of the hetero core optical fiber 1 in the hetero core portion 1a increases.

  Supplementally, although FIG. 2 exemplifies a case where the core diameter of the hetero core portion 1a is constant, the core 1a1 is arranged so that the core diameter of the hetero core portion 1a changes in the axial direction of the hetero core portion 1a. It may be formed. For example, the core 1a1 may be formed such that the core diameter of the hetero core portion 1a gradually decreases from both ends in the axial direction of the hetero core portion 1a toward the center side.

  The yarn 2 is a long continuous filament. The yarn 2 may be spun short fibers such as cotton yarn or wool, may be made of one long fiber such as raw yarn or synthetic fiber, or may be twisted long fibers. The yarn 2 may be a twisted yarn formed by twisting a plurality of yarns.

  The yarn 2 may be made of natural fibers such as wool, hemp, silk and wool, or synthetic fibers such as polyester.

  As shown in FIG. 3, the woven fabric 3 is obtained by weaving the hetero-core optical fiber 1 together with the yarn 2, and is configured as a deformation-sensitive woven fabric 100 having deformation sensitivity. The woven fabric 3 is produced by intersecting at least one hetero-core optical fiber 1 as a warp (warp) or a weft, a plurality of yarns 2 as a warp and a weft, and intersecting the warp and the weft. That is, the woven fabric 3 is woven by using the hetero core optical fiber 1 instead of the yarn 2 which becomes the warp yarn or the weft yarn.

  In this way, since the hetero-core optical fiber 1 is woven into the woven fabric 3, the woven fabric 3 becomes a cloth such as a garment like a normal woven fabric composed of only the thread 2, and the surface of a detection target such as a human body is excessively exposed. It can be covered without being bound to.

  Although the hetero core optical fiber 1 is used instead of the weft yarn 2 in FIG. 3, the hetero core optical fiber 1 may be used instead of the warp yarn 2.

  Further, although FIG. 3 shows an example in which the warp yarns and the weft yarns are woven together with a gap therebetween, they may be woven together without any gaps, and FIG. 3 shows an example in which they are woven with plain weave. However, the weave is not limited to this, and other known weaves such as twill weave and satin weave may be used.

  As shown in the cross-sectional view of the woven fabric 3 in FIG. 4A, when the hetero core optical fiber 1 is used as the weft yarn, the hetero core portion 1a of the hetero core optical fiber 1 is in contact with one of the warp yarns 2. At this time, it is preferable that the axial center part of the hetero core part 1a is in contact with the yarn 2.

  When the hetero-core optical fiber 1 and the yarn 2 are compared, the material of the hetero-core optical fiber 1 is harder than the material of the yarn 2, so that no tension is applied to the fabric 3 as shown in FIG. 4A. In the state, the curvature with respect to the hetero core portion 1a is very small. As described above, in the woven fabric 3, the yarn 2 made of a flexible fiber is used as a raw material to impart an appropriate degree of curvature to the hetero core portion 1a.

  From this state, when the woven fabric 3 is pulled in the direction in which the warp yarn extends, tension is also applied to the yarn 2, which is the warp yarn that contacts the hetero core portion 1a, and the yarn 2 decreases in diameter and becomes hard. As a result, as shown in FIG. 4B, the degree of curvature of the hetero core portion 1a increases as the hardness of the yarn 2 increases, and the propagation light intensity decreases due to leakage.

  Further, even when pressure, wrinkles, or folds are applied to the woven fabric 3, the degree of curvature of the hetero core portion 1a changes, so that these changes can be measured.

  The sensitivity differs depending on the position where the hetero core portion 1a and the thread 2 come into contact with each other. However, in general, the length of the hetero core portion 1a is about 1 mm to 2 mm, which is longer than the diameter of the yarn 2 and the distance between the yarns 2, so that the dependence on the position is not sensitive. Then, some individual changes in sensitivity may be individually calibrated at the time of use.

  In addition, the woven fabric 3 may be woven by plural hetero core optical fibers 1 instead of one. Furthermore, the hetero-core optical fiber 1 may be woven as warp threads or weft threads, or may be woven as warp threads and weft threads. However, in this case, it is not preferable that the hetero core parts 1a of the hetero core optical fiber 1 contact each other.

  As described above, since the deformation-sensitive fabric 100 includes the hetero-core optical fiber 1 woven into the flexible yarn 2 as a part of the material of the fabric 3, external deformation such as bending caused by the fabric 3 is applied. , Physical quantities such as expansion and contraction, pressure can be detected in real time as changes in light intensity without impairing the flexibility.

  If a single-mode fiber is used as the transmission line optical fiber 1b as the hetero-core optical fiber 1, the transmission line optical fiber 1b is resistant to disturbance such as bending and temperature change. Since it is not necessary to perform temperature compensation, versatility is enhanced.

  Further, when the deformation-sensitive fabric 100 is used as a fabric for clothing, physical movement due to body information such as arm and leg joints or biological information such as pulse and heartbeat is measured without a sense of restraint by the wearer. It becomes possible. Therefore, the deformation-sensitive fabric 100 can be brought into close contact with any measurement target surface such as the skin surface of the wearer.

  In addition, when the deformation-sensitive fabric 100 is formed into a sheet shape, the deformation-sensitive fabric 100 can be fixed to the skin surface of the measurement subject by sticking or the like so that a person does not feel a sense of incongruity such as a sense of restraint. Is.

  In this way, since the deformation-sensitive fabric 100 is deformed with high followability along with the deformation of the surface to be measured, it is possible to perform measurement with high accuracy.

  Next, a measurement method for detecting the deformation of an arbitrary measurement target surface using the deformation-sensitive fabric 100 will be described with reference to FIG.

  The deformation-sensitive fabric 100 is attached to the measurement object so that the deformation-sensitive fabric 100 is deformed along with the deformation of the surface of the measurement object (not shown). In this case, the deformation-sensitive fabric 100 can be attached to the measurement target by, for example, when the measurement target is a human body, by putting the deformation-sensitive fabric 100 in the shape of clothes or the like on the human body. Further, the deformation-sensitive fabric 100 may be formed into a band shape and attached to a human body's arm, wrist, leg, ankle or the like. In addition, the deformation-sensitive fabric 100 may be used as a fabric and sewn into various shapes.

  Further, the deformation-sensitive fabric 100 may be formed into a sheet shape and placed on the surface of the object to be measured or temporarily fixed by adhesion or the like.

  Then, for example, as shown in FIG. 5, measurement is performed using the detection device 10 to detect the deformation of the surface of the measurement target.

  The detection device 10 includes a deformation-sensitive fabric 100, a light source 11 that outputs light that enters the heterocore optical fiber 1 through an incident end, and a photodetector 12 that receives light emitted from the exit end of the heterocore optical fiber 1. , A data processing device 13 for taking in the output of the photodetector 12 via an AD converter (not shown).

  The light source 11 is composed of, for example, a light emitting diode (LED), a laser diode (LD), or the like, and is connected to one end of the transmission path optical fibers 1b, 1b of the hetero core optical fiber 1.

  The photodetector 12 is composed of, for example, a photodiode (PD) or the like, and is connected to the other end of the transmission path optical fibers 1b and 1b of the hetero core optical fiber 1.

  The data processing device 13 is composed of, for example, a computer such as a personal computer or an electronic circuit unit including a CPU and the like.

  Light is incident on the hetero core optical fiber 1 from the light source 11 of the detection device 10 having such a configuration, and the light emitted from the hetero core optical fiber 1 is detected by the photodetector 12.

  Then, the data processing device 13 measures the intensity of the emitted light indicated by the output of the photodetector 12, and the ratio of the measured value of the intensity of the emitted light and the predetermined intensity of the incident light is used as an index value, The transmission loss of light in the hetero core optical fiber 1 (hereinafter, simply referred to as optical loss) is measured. The optical loss of the hetero-core optical fiber 1 increases as the ratio of the intensity of emitted light to the intensity of incident light decreases.

  Here, when the surface of the measurement target is deformed, the surface of the measurement target is bulged or submerged, or the surface of the measurement target is elongated or shortened, which changes the degree of curvature of the hetero core 1a. For example, when the surface of the measurement object is raised, the hetero core portion 1a along the surface of the measurement object is lifted and the degree of curvature of the hetero core portion 1a is increased. The amount of light leakage in the hetero core portion 1a changes according to the change in the degree of curvature of the hetero core portion 1a. Therefore, it is possible to detect the deformation of the surface of the measurement object based on the measured value of the optical loss of the hetero core optical fiber 1.

  For example, when the surface of the measurement object is raised, the hetero core portion 1a is lifted, so that the degree of curvature of the hetero core portion 1a is increased, and the measured value of the optical loss of the hetero core optical fiber 1 is increased.

  On the contrary, when the surface of the measurement object sinks, the hetero core portion 1a lowers, so that the degree of curvature of the hetero core portion 1a decreases and the measured value of the optical loss of the hetero core optical fiber 1 decreases.

  Further, for example, when the yarn 2 that comes into contact with the hetero core portion 1a extends in the longitudinal direction due to the deformation of the surface of the measurement object, tension is generated in the yarn 2. When tension is applied to the yarn 2 in this manner, the yarn 2 becomes thin and hard, so that the degree of curvature of the hetero core portion 1a that contacts the yarn 2 increases. The amount of light leakage in the hetero core portion 1a changes according to the change in the degree of curvature of the hetero core portion 1a. Therefore, it is possible to detect the deformation of the surface of the measurement object based on the measured value of the optical loss of the hetero core optical fiber 1.

  For example, when the yarn 2 in contact with the hetero core portion 1a is elongated in the longitudinal direction due to the deformation of the surface of the object to be measured, the yarn 2 in contact with the hetero core portion 1a becomes thin and hard, so that the degree of curvature of the hetero core portion 1a increases. And the measured value of the optical loss of the hetero core optical fiber 1 increases.

  On the contrary, when the yarn 2 in contact with the hetero core portion 1a returns and shortens in the longitudinal direction due to the deformation of the surface of the measurement object, the yarn 2 in contact with the hetero core portion 1a returns and becomes thicker and softer. The degree of bending of the portion 1a decreases, and the measured value of the optical loss of the hetero core optical fiber 1 decreases.

  As described above, based on the measured value of the optical loss of the hetero core optical fiber 1, it is possible to detect the deformation of the surface of the measurement object, for example, the bulge or sink of the surface and the expansion and contraction.

[Verification test]
Next, a verification test of the operational characteristics of the embodiment of the deformation-sensitive fabric 100 will be described.

(Example)
The specifications of the embodiment of the produced deformation-sensitive fabric 100 used in the verification test are as follows.

  That is, a single-mode optical fiber having a core diameter of 9 μm and a single-mode optical fiber having a core diameter of 5 μm are used as the optical fibers of the transmission path optical fiber 1b and the hetero-core portion 1a, respectively, and the hetero-core optical structure shown in FIG. Fiber 1 was produced. The length of the hetero core portion 1a is 2 mm, and the outer diameters of the claddings 1a2 and 3b2 of the hetero core portion 1a and the transmission line optical fiber 1b are 125 μm. The transmission line optical fiber 1b and the optical fiber of the hetero core part 1a were joined by fusion.

  A yarn having an average diameter of 2 mm was used as the yarn 2. One heterocore optical fiber 1 is woven into this thread 2 as a weft thread, and a plain weave 3 having a size of 110 mm × 200 mm is formed by a plain weave with a gap of about 1.5 to 2.0 mm provided between the warp thread and the weft thread. It was made. The yarn 2 as one warp yarn is configured so as to be in contact with the center of the hetero core portion 1a of the hetero core optical fiber 1 in the radial direction directly above the center portion in the axial direction.

(Pressure characteristics)
A verification test for verifying the pressure characteristics of the deformation-sensitive fabric 100 will be described. In this verification test, the relationship between the pressure applied to the example of the woven fabric 3 and the optical loss of the hetero core optical fiber 1 was measured.

  The woven fabric 3 was placed on a flat metal stand that was sufficiently hard compared to the yarn 2. Then, pressure was applied to the woven fabric 3 from above by a load applying device having a circular load applying portion having a diameter of 13 mm at the tip with the hetero core portion 1a as the center. Then, the optical loss of the hetero core optical fiber 1 each time the applied pressure was increased by 1 N from 0 N to 20 N was measured using the detection device 10.

  FIG. 6 shows measurement data obtained by the verification test. The horizontal axis of FIG. 6 represents the pressure [N] applied to the woven fabric 3, and the vertical axis represents the relative optical loss [dB] based on the optical loss of the hetero core optical fiber 1 in the initial state of the woven fabric 3. ] Is represented.

  As shown in FIG. 6, when the applied pressure is increased in the range of 0 N to about 15 N, the relative optical loss of the hetero core optical fiber 1 monotonically increases as the pressure increases. It is considered that this is because as the pressure increases, the warp threads become thinner and the degree of bending of the hetero core portion 1a increases.

  On the other hand, in the range where the applied pressure exceeds about 15 N, it can be seen that the relative optical loss of the hetero core optical fiber 1 is almost constant and the increase is saturated even if the pressure is increased. It is considered that this is because when the pressure exceeds a predetermined value, the warp yarns that come into contact with the hetero core portion 1a change in shape flatly and the degree of curvature of the hetero core portion 1a does not substantially change.

  From the results of the above verification test, it was found that the deformation-sensitive fabric 100 has the ability to uniquely detect a minute change in the applied pressure. Therefore, the deformation-sensitive fabric 100 is considered to be useful for capturing a minute pressure change due to a pulse, a heartbeat, or the like that occurs on the surface of the human body.

(Bending property)
A verification test for verifying the bending characteristics of the deformation-sensitive fabric 100 will be described. In this verification test, the relationship between the bending applied to the example of the deformation-sensitive fabric 100 and the optical loss of the hetero core optical fiber 1 was measured.

  The experimenter grips the upper and lower ends of the woven fabric 3 (both ends in the direction in which the warp extends) with the fingers of the left and right hands, and bends the woven fabric 3 to have a roundness. At this time, bending was also given to the hetero core portion 1a. The optical loss of the hetero core optical fiber 1 in this state was measured for 3 seconds using the detection device 10.

  Line A in FIG. 7 shows the measurement data obtained by such a verification test. The horizontal axis of FIG. 7 represents the elapsed time [second], and the vertical axis represents the relative optical loss [dB] based on the optical loss of the hetero core optical fiber 1 in the initial state of the fabric 3. There is.

  As shown by the line A in FIG. 7, the relative optical loss of the hetero core optical fiber 1 was about 2.0 dB. It is considered that this is because the hetero core portion 1a is curved.

  The optical loss of the hetero core optical fiber 1 slightly changes with time. It is considered that this is a detection of a slight vertical shaking of the experimenter's hand.

  On the other hand, the experimenter grips the left and right ends of the woven fabric 3 (both ends in the direction in which the weft extends) by bending the woven fabric 3 so as to have a roundness. At this time, no bending is applied to the hetero core portion 1a. Then, the optical loss of the hetero core optical fiber 1 in this state was measured for 3 seconds using the detection device 10.

  Line B in FIG. 7 shows the measurement data obtained by such a verification test. As shown by the line B in FIG. 7, the relative optical loss of the hetero core optical fiber 1 was constant at 0 dB. It is considered that this is because the degree of bending of the hetero core portion 1a did not change. The optical loss of the hetero core optical fiber 1 does not change with time. It is considered that this is because a slight up-and-down tremor of the experimenter's hand was not detected because the hetero core 1a was not curved.

  From the results of the above verification test, it was found that the deformation-sensitive fabric 100 has a capability of detecting the bending deformation applied according to the bending direction. Therefore, the deformation-sensitive fabric 100 is considered useful because it can detect the magnitude of bending deformation according to the bending direction. Furthermore, by not only weaving the hetero-core optical fiber 1 in place of the weft of the fabric 3 but also weaving the hetero-core optical fiber 1 in the warp, it is possible to detect the magnitude of bending deformation in the two-dimensional direction. To be

(Stretchability)
A verification test for verifying the stretchability of the deformation-sensitive fabric 100 will be described. In this verification test, the relationship between the expansion and contraction applied to the example of the deformation-sensitive fabric 100 and the optical loss of the heterocore optical fiber 1 was measured.

  The fabric 3 was placed on a flat platform made of plastic that was sufficiently hard compared to the yarn 2. Then, the experimenter reciprocates vertically while pressing both upper and lower ends (both ends in the extending direction of the warp threads) of the woven fabric 3 against the base with fingers of the left and right hands. The optical loss of the hetero core optical fiber 1 in this state was measured for 6 seconds using the detection device 10.

  FIG. 8A shows measurement data obtained by the verification test. The horizontal axis of FIGS. 8A and 8B represents elapsed time [seconds], and the vertical axis represents relative optical loss [dB] based on the optical loss of the hetero core optical fiber 1 in the initial state of the fabric 3. Is represented.

  As shown in FIG. 8A, the relative optical loss of the hetero core optical fiber 1 periodically changed between 0 dB and about 0.5 dB. This is because when the warp yarn extends, the degree of curvature of the hetero core portion 1a increases and the light loss increases, and when the warp yarn shortens, the degree of curvature of the hetero core portion 1a decreases and the light loss decreases. It is believed that there is.

  On the other hand, the experimenter reciprocates vertically while pressing the left and right ends (the ends in the extending direction of the weft) of the fabric 3 placed on the table with the fingers of the left and right hands on the table. The optical loss of the hetero core optical fiber 1 in this state was measured for 6 seconds using the detection device 10.

  FIG. 8B shows measurement data obtained by the verification test. As shown in FIG. 8B, the relative optical loss of the hetero core optical fiber 1 was constant at 0 dB. It is considered that this is because the degree of bending of the hetero core portion 1a of the hetero core optical fiber 1 woven in place of the weft did not change due to the lateral expansion and contraction of the woven fabric 3.

  From the results of the above verification test, it was found that the deformation-sensitive fabric 100 has the ability to detect the applied expansion and contraction according to the direction of expansion and contraction. Therefore, the deformation-sensitive fabric 100 is considered useful because it can detect the amount of expansion and contraction according to the direction of expansion and contraction. Furthermore, by not only weaving the hetero core optical fiber 1 in place of the weft yarn of the deformation-sensitive fabric 100 but also weaving the hetero core optical fiber 1 in the warp yarn, it becomes possible to detect the magnitude of expansion and contraction in the two-dimensional direction. Conceivable.

(Pulse measurement test)
A pulse measurement test using the deformation-sensitive fabric 100 will be described.

  In this test, as shown in FIG. 9, the deformation-sensitive fabric 100 was placed on the right wrist of the subject. At this time, it was arranged so that the center of the hetero core portion 1a was in contact with the skin almost directly above the pulse measurement position. The woven fabric 3 was merely placed on the wrist and not fixed. Then, the optical loss of the hetero core optical fiber 1 in this state was measured for 10 seconds using the detection device 10.

  FIG. 10 shows measurement data obtained by such a pulse measurement test. The horizontal axis of FIG. 10 represents the elapsed time [seconds], and the vertical axis represents the optical loss [dB] of the hetero core optical fiber 1.

  As shown in FIG. 10, it can be seen that the optical loss of the hetero core optical fiber 1 periodically changes with the passage of time. It is considered that this is because the degree of curvature of the hetero core portion 1a periodically changes due to the pressure caused by the subtle vertical movement that occurs on the surface of the skin at the pulse measurement position due to the pulsation of the subject.

  The optical loss of the hetero-core optical fiber 1 has a periodic fluctuation of 11 times in 10 seconds, and it has been found that the pulse rate per a predetermined time can be obtained.

  From the results of the pulse measurement test described above, it was found that the deformation-sensitive fabric 100 has a capability of detecting a change over time in minute pressure due to pulsation at the pulse measurement position. Therefore, the deformation-sensitive fabric 100 can measure the pulse rate generated on the body surface of the human body and is considered to be useful.

  It is also understood that the optical loss of the hetero-core optical fiber 1 is approximately constant at about 0.04 dB in each cycle, and there is a possibility that pressure fluctuation due to pulsation, that is, pulse pressure can also be measured.

  The optical loss of the hetero-core optical fiber 1 increased slightly but increased with time. It is considered that this is because the position of the hetero core portion 1a with respect to the wrist of the subject slightly deviated with the passage of time. In order to prevent such a situation, the deformation-sensitive fabric 100 may be fixed to the wrist of the subject by a known fixing means such as an adhesive tape or a rubber band.

(Hand open / close measurement test)
A hand open / close measurement test using the deformation-sensitive fabric 100 will be described.

  In this test, as shown in FIG. 11, the fabric 3 was wrapped around the tip of the right forearm of the subject. At this time, the woven fabric 3 was arranged so that the center of the hetero-core part 1a was in contact with the skin located directly above the muscle that operates according to the opening and closing of the hand. Then, in this state, the subject repeatedly measured the optical loss of the hetero-core optical fiber 1 for 7 seconds using the detection device 10 while repeatedly opening and closing the hand.

  FIG. 12 shows measurement data obtained by such a hand opening / closing test. The horizontal axis of FIG. 12 represents the elapsed time [second], and the vertical axis represents the optical loss [dB] of the hetero core optical fiber 1.

  As shown in FIG. 12, the optical loss of the hetero core optical fiber 1 was about 0.1 dB when the hand was opened. This is because the hetero-core optical fiber 1 is bent in the circumferential direction of the forearm. Also, it can be seen that when the hand is closed, it is as large as about 0.6 to 0.8 dB. It is considered that this is because the muscle at the measurement position operates due to the opening and closing of the hand of the subject, and a slight vertical fluctuation occurs on the surface of the skin, and the resulting pressure changes the degree of bending of the heterocore portion 1a.

  From the results of the hand opening / closing test described above, it was found that the deformation-sensitive fabric 100 has a capability of detecting a minute change in pressure due to a minute movement of a muscle accompanying opening / closing of the hand. Therefore, it is considered that the deformation-sensitive fabric 100 can measure the movement of the muscle generated on the body surface of the human body and can detect the movement of the joints at various places.

  Further, the optical loss of the hetero core optical fiber 1 may be able to measure the joint angle.

  The maximum value of the optical loss of the hetero-core optical fiber 1 increased slightly with the passage of time. It is considered that this is because the position of the hetero core portion 1a with respect to the wrist of the subject slightly deviated with the passage of time. In order to prevent such a situation, the deformation-sensitive fabric 100 may be fixed to the wrist of the subject by a known fixing means such as an adhesive tape or a rubber band.

[Second Embodiment]
Next, a second embodiment of the present invention will be described below with reference to the drawings. The present embodiment is different from the first embodiment only in the structure of the woven fabric 6 in which the hetero core optical fiber 1 is woven. Therefore, description of the same items as those in the first embodiment will be omitted.

  As shown in FIGS. 13A and 13B, in the deformation-sensitive fabric 100A that is the second embodiment of the optical fiber type sensor device of the present invention, the hetero-core optical fiber 1 has a yarn over at least a part in the longitudinal direction. A plurality of yarns or fibers that have been unwound from 2 are twisted together to form an optical fiber incorporated twisted yarn 4. Then, the plurality of threads 2 are woven as warp threads or weft threads, and the whole is woven into a woven fabric or cloth. A plurality of heterocore optical fibers 1 may be twisted together with one or a plurality of yarns 2 in one optical fiber incorporated twisted yarn 4, and one optical fiber incorporated twisted yarn 4 may be twisted into a plurality of heterocore optical fibers 1. You may form only by twisting.

  When the optical fiber incorporated twisted yarn 4 is used as a weft yarn, the optical fiber incorporated twisted yarn is produced in a projection space in which the hetero core portion 1a of the hetero core optical fiber 1 is projected in the direction of the yarn 2 which is a warp yarn in contact with the hetero core optical fiber 1. 4 and the thread 2 are in contact with each other. At this time, it is preferable that the optical fiber incorporated twisted yarn 4 and the yarn 2 are in contact with each other in a projection space in which the axial center of the hetero core portion 1a is projected in the direction of the yarn 2. In FIG. 13A, the optical fiber incorporating twisted yarn 4 and the yarn 2 are in contact with each other below the hetero core portion 1a.

  Since the material of the hetero-core optical fiber 1 is harder than the material of the thread 2, as shown in FIG. 13A, the curvature to the hetero-core portion 1a is very high in the state where no tension is applied in the warp direction of the fabric 5. small.

  From this state, when the woven fabric 6 is pulled in the extending direction of the warp yarn, tension is also applied to the yarn 2 as the warp yarn which comes into contact with the optical fiber incorporated twisted yarn 4, and the yarn 2 has a reduced diameter and becomes hard. As a result, as shown in FIG. 13B, the curvature degree (average curvature) of the hetero core portion 1a increases as the hardness of the yarn 2 increases, and the propagation light intensity decreases due to leakage.

(Verification test)
Next, a verification test of operation characteristics of the embodiment of the deformation-sensitive fabric 100A will be described.

(Example)
The specifications of the example of the deformation-sensitive fabric 100A produced for use in the verification test are as follows.

  That is, a single-mode optical fiber having a core diameter of 9 μm and a single-mode optical fiber having a core diameter of 5 μm are used as the optical fibers of the transmission line optical fiber 1b and the hetero-core portion 1a, respectively, and the hetero-core optical structure shown in FIG. Fiber 1 was produced. The length of the hetero core portion 1a is 2 mm, and the outer diameters of the claddings 1a2 and 3b2 of the hetero core portion 1a and the transmission line optical fiber 1b are 125 μm. The transmission line optical fiber 1b and the optical fiber of the hetero core part 1a were joined by fusion.

  A yarn having an average diameter of 2 mm was used as the yarn 2.

  Then, one yarn 2 was unraveled and divided into four yarns, and the hetero-core optical fiber 1 was incorporated and twisted in the center of the four yarns to prepare an optical fiber incorporated twisted yarn 4. Then, the yarn 2 was woven into the warp yarn and the weft yarn, and the single twisted yarn 4 incorporating the optical fiber was woven as the weft yarn, and a plain weave 6 having a size of 50 mm × 90 mm was produced by plain weaving with no gap between the warp yarn and the weft yarn. The yarn 2 as one warp yarn is configured so as to be in contact with the center of the hetero core portion 1a of the hetero core optical fiber 1 in the radial direction directly above the center portion in the axial direction.

(Stretchability)
A verification test for verifying the stretchability of the deformation-sensitive fabric 100A will be described. In this verification test, the relationship between the expansion and contraction applied to the example of the deformation-sensitive fabric 100A and the optical loss of the heterocore optical fiber 1 was measured.

  One end of the fabric 6 in the up-down direction (the direction in which the warp extends) was fixed with a metal and a plastic on a flat fixing base made of a metal sufficiently harder than the yarn 2. Then, the other end in the vertical direction of the woven fabric 6 was fixed with a metal and a plastic on a flat movable stage made of the same material as that of the fixed base. Then, the movable stage was reciprocally moved in steps of 0.1 mm in a direction away from the fixed base to 1 mm. The optical loss of the hetero core optical fiber 1 in such a state was measured using the detection device 10.

  The measurement data by the verification test concerning the lines A and B of FIG. 14 are shown. The horizontal axis of FIG. 14 represents the displacement amount [mm], and the vertical axis represents the relative optical loss [dB] based on the optical loss of the hetero core optical fiber 1 in the initial state of the fabric 6. There is.

  As shown by the line A in FIG. 14, the optical loss of the hetero core optical fiber 1 monotonically increased as the woven fabric 6 extended in the vertical direction. This is because when the woven fabric 6 stretches, the warp yarn 2 also stretches and becomes thin and hard, so that the degree of curvature of the hetero core portion 1a of the hetero core optical fiber 1 in the optical fiber built-in twisted yarn 4 that comes into contact with this becomes large. It is considered that this is because the optical loss increased.

  On the other hand, when the fabric 6 was shortened in the vertical direction, as shown by the line B in FIG. 14, the optical loss of the hetero core optical fiber 1 decreased monotonically as it shortened. This is because when the woven fabric 6 is shortened, the warp yarn 2 is also shortened and becomes thicker and softer, so that the degree of curvature of the hetero core portion 1a of the hetero core optical fiber 1 in the optical fiber built-in twisted yarn 4 which is in contact therewith is reduced. It is considered that this is because the light loss is reduced.

  It was also confirmed that the change in the optical loss of the hetero core optical fiber 1 has a hysteresis characteristic when the fabric 6 is stretched in the vertical direction and when it is shortened. In the measurement data shown by the lines A and B in FIG. 14, the optical loss of the hetero core optical fiber 1 is different between the case where the woven fabric 6 is stretched in the vertical direction and the case where the woven fabric 6 is shortened, even if the stretch amount of the fabric 6 is the same. Are slightly different.

  Next, one end portion of the woven fabric 6 in the left-right direction (the direction in which the weft extends) was fixed on the fixing base with metal and plastic. Then, the other end of the fabric 6 in the left-right direction was fixed on the movable stage with metal and plastic. Then, the movable stage was reciprocally moved in steps of 0.1 mm in a direction away from the fixed base to 1 mm. The optical loss of the hetero core optical fiber 1 in such a state was measured using the detection device 10.

  Line C in FIG. 14 shows the measurement data obtained by the verification test.

  As shown by the line C in FIG. 14, the optical loss of the hetero core optical fiber 1 was the same regardless of the extension amount of the fabric 6 in the left-right direction. This is because even if the fabric 6 is stretched or contracted in the left-right direction, the warp yarns are not stretched or contracted, so that the degree of curvature of the hetero core portion 1a of the hetero core optical fiber 1 in the twisted yarn 4 incorporating the optical fiber is also the same. This is probably because the light loss did not change.

(Stretch sensitivity depending on the material)
A verification test for verifying the stretch sensitivity of the deformation-sensitive fabric 100A due to the difference in material will be described.

  The material of the yarn 2 was changed, and the above-described twisted yarn 4 incorporating the optical fiber was produced. Then, for each of these materials, a verification test for verifying the expansion and contraction characteristics was performed for the case where the fabric 6 was stretched in the vertical direction.

  As shown by the lines A and B in FIG. 14, when the yarn 2 is a yarn having a diameter of 2 mm, the relative increase in the optical loss of the hetero core optical fiber 1 at the displacement amount of 1 mm was about 0.2 dB. .

  When the yarn 2 is made of cotton and has a diameter of 0.7 mm, the relative increase in the optical loss of the hetero core optical fiber 1 at the displacement of 1 mm was about 1.31 dB.

  When the thread 2 is made of silk and has a diameter of 0.7 mm, the relative increase of the optical loss of the hetero core optical fiber 1 at the displacement amount of 0.5 mm was about 0.88 dB.

  When the thread 2 is made of polyester and has a diameter of 0.5 mm, the relative increase in the optical loss of the hetero core optical fiber 1 at the displacement amount of 1 mm was about 1.29 dB.

  From these results, it has been found that the harder the material of the yarn 2, the more the stretch sensitivity increases.

[Modification]
Next, a modification of the present invention will be described.

  In the deformation-sensitive fabrics 100 and 100A shown in the first and second embodiments, the case where the hetero-core optical fiber 1 or the optical fiber-embedded twisted yarn 4 is woven into the fabrics 3 and 6 as warps or wefts has been described. . However, the deformation-sensitive fabric incorporating the optical fiber of the present invention is not limited to this.

  For example, the deformation-sensitive fabric incorporating the optical fiber of the present invention may be configured as a knitted fabric in which the hetero core optical fiber 1 or the optical fiber incorporating twisted yarn 4 is knitted together with the yarn 2. The knitting method is, for example, flat knitting or rubber knitting, but is not limited to these.

  A coating layer may be provided on the surface of the woven fabric 3, 6 or the knitted fabric. For example, a layer made of a material such as vinyl or polyurethane used for clothing or the like can be used as the coating layer. This makes it possible to give the woven fabric 3, 6 or the knitted fabric an effect corresponding to the coating layer.

  Furthermore, the deformation-sensitive fabrics 100 and 100A shown in the first and second embodiments are configured using the heterocore optical fiber 1 having the heterocore portion 1a. However, the deformation-sensitive fabric incorporating the optical fiber of the present invention is not limited to the hetero-core optical fiber 1 as long as it can change the light transmission characteristics with a relatively high correlation in accordance with the degree of curvature of the light transmitting portion. Optical fibers can also be used.

  For example, a long-period optical fiber grating may be used as the optical fiber other than the hetero core optical fiber 1. In this case, since the resonance wavelength shifts depending on the degree of curvature of the optical fiber, it is possible to detect the degree of curvature of the optical fiber based on the spectrum of the transmitted light in the optical fiber.

  100, 100A ... Deformation sensitive fabric, deformation sensitive fabric incorporating optical fiber, 1 ... Hetero core optical fiber (optical fiber), 1a ... Hetero core part, 1a1 ... Core, 1a2 ... Clad, 1b ... Transmission line optical fiber, 1b1 ... Core , 1b2 ... Clad, 2 ... Yarn, 3,6 ... Woven fabric, 4 ... Optical fiber incorporated twisted yarn, 5 ... Twisted yarn, 10 ... Detection device, 11 ... Light source, 12 ... Photodetector, 13 ... Data processing device.

Claims (7)

It has cores of different diameters and clads provided on the outer periphery of the cores, and has a hetero core part that leaks part of the transmitted light, and the light that is incident from the incident end and passes through the hetero core part is emitted from the emission end. Consisting of a woven or knitted fabric made by weaving or knitting optical fibers with threads,
The hetero core portion and the yarn crossing the optical fiber having the hetero core portion are in contact with each other,
A deformation-sensitive fabric incorporating an optical fiber, wherein the propagation light intensity of the optical fiber changes according to the expansion and contraction deformation of the yarn that comes into contact with the optical fiber having the hetero core portion . It has cores of different diameters and clads provided on the outer periphery of the cores, and has a hetero core part that leaks part of the transmitted light, and the light that is incident from the incident end and passes through the hetero core part is emitted from the emission end. An optical fiber incorporating twisted yarn in which an optical fiber is twisted with a yarn, and a woven fabric or a knitted fabric produced by weaving or knitting together only a twisted yarn or a yarn
In the hetero-core portion and the twisting or projection space is projected in the direction of the yarn, the twisting or the yarn and the contacts intersecting with the optical fiber built-twisting containing the optical fiber having the hetero-core portion and the hetero-core portion and,
Deformation-sensitive fabric incorporating an optical fiber, characterized in that the propagating light intensity of the optical fiber included in the twisted yarn incorporating the optical fiber changes according to the expansion and contraction deformation of the twisted yarn or the yarn that comes into contact with the twisted yarn incorporating the optical fiber. .   The deformation-sensitive fabric incorporating the optical fiber according to claim 1 or 2, wherein the woven or knitted fabric is configured to be attached to a detection target. The deformation sensitive fabric incorporating the optical fiber according to claim 3, wherein the hetero core portion is arranged such that a direction orthogonal to a variation direction of the detection target is a longitudinal direction.   The deformation-sensitive fabric incorporating an optical fiber according to claim 3 or 4, wherein the object to be detected is a human body, and the woven or knitted fabric is configured like a garment.   A deformation-sensitive fabric incorporating the optical fiber according to any one of claims 1 to 5, comprising a coating layer on the surface of the woven or knitted fabric. A deformation-sensitive fabric incorporating the optical fiber according to any one of claims 1 to 6,
A light source that outputs light incident on the optical fiber from the incident end,
And a photodetector that receives light emitted from the emission end of the optical fiber.