JP2011102695A - Weight-measuring element and weighing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a weight-measuring element by which an inexpensive, high-precision weighing apparatus can be obtained, and the weighing apparatus. <P>SOLUTION: Light enters an entrance end of an optical fiber (20a, 20b) having a core and a clad formed at the periphery of the core and an optical transmission member allowing interaction between a part of light to be transmitted and an outside field, and the light passing through the optical transmission member (SP) exits from an exit end. A first substrate 1 is placed below the optical fiber so that at least the part of the optical transmission member and a part in the vicinity thereof are mounted. A second substrate 3 formed with an opening 3a is placed above the optical fiber so that the part of the optical transmission member is positioned within an area of the opening. A pressing member 4 formed of a material which is harder than the first substrate and the second substrate is fit into the opening. A load equalizing substrate 5 is provided on the second substrate and the pressing member. A part of the pressing member pressing the part of the optical transmission member of the optical fiber generates a bend in the vicinity of the optical transmission member of the optical fiber when a load is applied to the pressing member. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a weight measuring element for measuring weight and a weight scale using the same, and more particularly to a weight measuring element using an optical fiber sensor and a weight scale using the same.

As a scale for measuring the weight of an object to be weighed, for example, a method is widely used in which a compression spring is deformed when weight acts on a pedestal or the like.
Usually, the pointer is rotated or moved according to the magnitude of deformation of the compression spring, and the pointer indicates a weight value corresponding to the weight of the object to be weighed.

Further, a weight element that converts the deformation amount of the compression spring into an electrical signal and electrically measures the weight is widely used.
In this case, for example, a weight scale that converts the weight of an object to be weighed into an electric signal and measures the weight from the amount of change in the electric signal is also known.

On the other hand, as disclosed in Patent Documents 1 and 2, hetero-core type optical fiber sensors have been developed.
Patent Documents 3 and 4 disclose weight scales using optical fibers.
International Publication No. 97/48994 Pamphlet JP 2003-214906 A JP 2002-188952 A Japanese Patent Laid-Open No. 2002-168677

However, it is difficult to increase the accuracy of weight measurement with a conventional weighing scale. To achieve high accuracy, the structure is complicated and the manufacturing cost is expensive.
Furthermore, in conventional scales using electrical signals, etc., an electrical sensor is used, so there is a risk of electrical leakage even if a small amount of water is applied, and it was necessary to take all possible waterproofing measures. . Furthermore, since it electrically senses and sends and receives electrical signals, it cannot be used in explosion-proof facilities.

  The problem to be solved is that it is difficult to realize an inexpensive and highly accurate weighing scale.

  The weight measuring element of the present invention includes a core and a clad provided on the outer periphery of the core, and includes a light transmitting member that enables interaction with a part of the transmitted light, and light enters the incident end. An optical fiber that emits light that has passed through the light transmission member from an emission end, a first substrate that is disposed below the optical fiber so as to place at least a portion of the light transmission member and its vicinity, and an opening A second substrate disposed above the optical fiber so that at least a portion of the light transmitting member is located in the region of the opening, and is fitted into the opening, and the first substrate and A pressing member made of a material having a hardness higher than that of the second substrate; a load equalizing substrate provided on the second substrate and the pressing member; and the light transmitting member of the optical fiber of the pressing member. The part that presses the part The optical fiber has a shape that generates a bend in the vicinity of the light transmitting member of the optical fiber when a load is applied to the pressing member, and transmits the optical fiber when a load is applied to the load uniformizing substrate. It is the structure which generate | occur | produces the loss according to the said load with respect to the light to perform.

The weight measuring element of the present invention includes a core and a clad provided on the outer periphery of the core, and is provided at an incident end of an optical fiber having a light transmitting member that enables interaction with a part of the transmitted light. Light is incident and light passing through the light transmission member is emitted from the emission end, and the first substrate is disposed below the optical fiber so that at least the light transmission member portion and the vicinity thereof are placed, and an opening is provided. The second substrate is disposed above the optical fiber so that at least a portion of the light transmitting member is located in the region of the opening, and the pressing member is made of a material harder than the first substrate and the second substrate in the opening. Is inserted, and a load equalizing substrate is provided on the second substrate and the pressing member.
Here, the portion of the pressing member that presses the light transmitting member of the optical fiber has a shape that causes bending in the vicinity of the light transmitting member of the optical fiber when a load is applied to the pressing member, and the load is uniform. In this configuration, a loss corresponding to the load is generated with respect to light transmitted through the optical fiber when a load is applied to the substrate.

  The weight measuring element of the present invention preferably includes a protective sheet for protecting the optical fiber between the second substrate, the pressing member, and the optical fiber.

  The weight measuring element according to the present invention preferably communicates with the opening in a side wall portion in a direction orthogonal to the direction in which the optical fiber is arranged in the vicinity of the light transmitting member of the opening. A cut portion is formed.

  In the weight measuring element of the present invention, preferably, the height of the pressing member is substantially equal to the thickness of the second substrate.

  In the weight measuring element of the present invention, preferably, a portion of the pressing member that presses the light transmitting member of the optical fiber is rounded or pointed.

  In the weight measuring element of the present invention, preferably, the pressing member is made of metal or silicone rubber, and the first substrate and the second substrate are made of silicone rubber.

  In the weight measuring element of the present invention described above, preferably, the light transmitting member is a hetero-core portion having a core diameter different from the core diameter of the optical fiber. Alternatively, preferably, the light transmitting member is a light transmitting member having a refractive index equivalent to a refractive index of a core of the optical fiber or a refractive index of a clad.

  The weighing scale according to the present invention includes a gravity measuring element including an optical fiber, a light source provided at an incident end of the optical fiber, and a light receiving unit provided at an output end of the optical fiber. The weight measuring element includes a core and a clad provided on the outer periphery of the core, and includes a light transmitting member that enables interaction with a part of the transmitted light, and light is incident on the incident end. An optical fiber that emits light that has passed through the light transmission member from an emission end, a first substrate that is disposed below the optical fiber so as to place at least a portion of the light transmission member and its vicinity, and an opening A second substrate disposed above the optical fiber so that at least a portion of the light transmitting member is located in the region of the opening, and is fitted into the opening, and the first substrate and Harder than the second substrate A pressing member made of a material, and a load uniformizing substrate provided on the second substrate and the pressing member, and the portion of the pressing member that presses the portion of the light transmitting member of the optical fiber is Light that generates a bend in the vicinity of the light transmitting member of the optical fiber when a load is applied to the pressing member, and transmits the optical fiber when a load is applied to the load equalizing substrate In contrast, a loss corresponding to the load is generated.

The weight meter of the present invention described above includes a light source at the incident end of the optical fiber and a light receiving portion at the output end of the gravity measuring element including the optical fiber. Is provided with a light transmitting member that enables interaction with the outside of a part of the transmitted light in the middle of the optical fiber including the core and the cladding provided on the outer periphery of the core. The first substrate is disposed below the optical fiber so that the member portion and the vicinity thereof are placed, and the second substrate provided with the opening is positioned so that at least the light transmissive member portion is located in the region of the opening. A pressing member made of a material harder than the first substrate and the second substrate is inserted into the opening, and a load equalizing substrate is provided on the second substrate and the pressing member.
Here, in the weight measuring element, the portion of the pressing member that presses the light transmitting member of the optical fiber has a shape that causes bending of the light transmitting member of the optical fiber when a load is applied to the pressing member. There is a configuration in which a loss corresponding to the load is generated for light transmitted through the optical fiber when a load is applied to the load uniformizing substrate.

  In the weighing scale according to the present invention, preferably, the light source is a semiconductor light emitting diode, a semiconductor laser, or white light.

  The weight measuring element of the present invention is configured to generate a loss for the light transmitted through the optical fiber in accordance with the load applied to the load uniformizing substrate, and to realize an inexpensive and highly accurate weighing scale. Can do.

  In addition, the weight scale of the present invention is configured to generate a loss for light transmitted through the optical fiber according to the load applied to the load uniformizing substrate, and is a cheap and highly accurate weight scale.

  Hereinafter, embodiments of a weight measuring element and a weight scale using the same according to the present invention will be described with reference to the drawings.

First Embodiment FIG. 1 is a schematic configuration diagram of a weigh scale according to the present embodiment.
For example, the weight measuring element WM is provided in the middle of the optical fiber (20a, 20b).
Further, for example, a light source 11 such as a semiconductor light emitting diode or a semiconductor laser that emits sensor light is provided at the light incident end of the optical fiber 20a, and sensor light emitted from the light emitting end is provided at the light emitting end of the optical fiber 20b. A light receiving unit 12 such as an optical multimeter for detection is provided.
The weighing scale according to the present embodiment is configured as described above.

FIG. 2 is a perspective view of the weight measuring element of the present embodiment constituting the weighing scale according to the present embodiment, and FIG. 3 is a configuration explanatory view for explaining the structure of the weight measuring element shown in FIG.
4A is a plan view of the weight measuring element, FIG. 4B is a cross-sectional view taken along the line XX ′ in FIG. 4A, and FIG. 4C is FIG. It is sectional drawing in YY 'in the inside.

For example, the sensor fiber is placed on the first substrate 1 made of silicone rubber having a thickness of about 2 to 4 mm.
The sensor fiber is, for example, a light transmission member that enables interaction with a part of the transmitted light in the middle part of the optical fiber (20a, 20b) including a core and a clad provided on the outer periphery of the core. The at least sensor part SP (light transmissive member part) and the vicinity thereof are arranged on the first substrate 1.
In the optical fibers (20a, 20b) constituting the sensor fiber, the light source 11 is provided at the light incident end of the optical fiber 20a as described above, and the light receiving unit 12 is provided at the light emitting end of the optical fiber 20b.

Further, for example, a protective sheet 2 for protecting a sensor fiber made of a urethane sheet having a thickness of 0.5 mm is disposed on the sensor fiber, and a silicone rubber having a thickness of about 2 to 4 mm is disposed on the upper layer. The 2nd board | substrate 3 which consists of is arrange | positioned.
In the second substrate 3, for example, a rectangular opening 3 a having one side (a) of about 2 to 4 mm and the other side (b) of about 10 mm (see FIG. 4A) is provided.
The sensor fiber and the second substrate 3 are arranged so that the sensor part SP of the sensor fiber is located in the region of the opening 3a.

  Further, for example, the bottom surface is a circle having a diameter of about 2 to 4 mm, the columnar shape has a height of about 10 mm, and is made of metal or silicone rubber, which is a material harder than the first substrate 1 and the second substrate 3. The pressing member 4 is inserted into the opening 3 a so that the side surface which is a cylindrical curved surface is in contact with the protective sheet 2. That is, the opening 3a is shaped such that the cylindrical pressing member 4 is just inserted. As will be described later, the pressing member 4 has a shape that causes bending in the vicinity of the sensor portion SP of the sensor fiber when a load is applied to the pressing member 4.

  Further, for example, in the vicinity of the sensor part SP of the fiber sensor, a notch 3b communicating with the opening 3a is formed in a side wall portion in a direction orthogonal to the direction in which the fiber sensor of the opening 3a of the second substrate 3 is arranged. Is formed. For example, the cut portion 3b has a length s = 2 to 4 mm and a width t = 2 to 4 mm (see FIG. 4A).

  Further, for example, a load uniformizing substrate 5 made of an acrylic plate having a thickness of about 2 to 4 mm is provided on the second substrate 3 and the pressing member 4.

For example, the portion that presses the sensor portion SP of the fiber sensor of the pressing member 4 has a shape that causes bending in the vicinity of the sensor portion SP of the fiber sensor when a load is applied to the pressing member 4. . In this embodiment, it arrange | positions so that the side surface which is a curved surface of the column-shaped press member 4 may correspond to the part of sensor part SP of a fiber sensor via the protection sheet 2. FIG.
The weight measuring element WM is configured as described above.

FIG. 5A is a perspective view of the vicinity of the sensor part SP of the fiber sensor constituting the weight measuring element according to the present embodiment, and FIG. 5B is a longitudinal sectional view of the vicinity of the sensor part SP.
For example, the optical fiber sensor used in the measurement apparatus of the present embodiment has a configuration in which the sensor unit SP is provided between one optical fiber 20a and the other optical fiber 20b, which are multimode fibers having a core diameter of 50 μm. .
The sensor unit SP includes, for example, a hetero core unit 30 that is a light transmitting member that enables interaction of a part of transmitted light with the outside world.

For example, the optical fiber (20a, 20b) has a core 21 and a clad 22 provided on the outer periphery thereof, and the hetero-core part 30 has a core diameter different from the core diameter of the optical fiber (20a, 20b). It has the core 31 and the clad 32 provided in the outer peripheral part.
Further, for example, the diameter bl of the core 31 in the hetero-core portion 30 is smaller than the diameter al of the core 21 of the optical fiber (20a, 20b), for example, al = 9 μm and bl = 5 μm. Moreover, the length cl of the hetero core part 30 is about 1-2 mm, for example.
The hetero-core part 30 and the optical fibers (20a, 20b) constituting the sensor part SP are, for example, substantially coaxial so that the cores are bonded to each other at the interface 40 orthogonal to the longitudinal direction, for example, fusion by discharge that has been widely used. Etc. are joined together.

  As the optical fiber (20a, 20b) and the hetero core part 30, for example, any of a single mode optical fiber and a multimode optical fiber can be used, and these may be used in combination.

  In the configuration in which the hetero core type sensor part SP is joined to the middle part of the optical fiber (20a, 20b), the diameter bl of the core 31 in the hetero core part 30 and the diameter al of the core 21 of the optical fiber (20a, 20b). Are different at the interface 40, and due to the difference in the core diameter, as shown in FIG. 5A, a leak W to the clad 32 of the hetero-core portion 30 of a part of the light occurs.

When the combination of the diameters of the core 21 and the core 31 is set so that the leak W becomes small, most of the light enters the core 21 again and is transmitted. Depending on the combination of the diameters of the core 21 and the core 31, the leak W increases and the loss of transmitted sensor light also increases. If the leak W is reduced, the loss is also reduced.
In the hetero-core type sensor unit, the magnitude of the leak W, that is, the loss amount of the sensor light changes sharply due to the change in the bending of the optical fiber near the sensor unit.

Next, the operation of the weight measuring element WM will be described.
For example, in the above-described weight measuring element WM, when a measurement target is placed on the load uniformizing substrate 5, a load corresponding to the weight of the measurement target is applied to the load uniformizing substrate 5. As a result, the load is transmitted to the pressing member 4 and the second substrate 3 arranged on the load uniformizing substrate 5. At this time, even if the load applied to the upper surface of the load uniformizing substrate 5 is non-uniform, the load transmitted to the lower portion is made more uniform and evenly transmitted to the pressing member 4 and the second substrate 3. The

The pressing member 4 is made of a material that is harder than the second substrate 3, and when the second substrate 3 receives a load, the pressing member 4 is more crushed than the pressing member 4, and the pressing member 4 is less crushed. . In addition, the first substrate 1 made of a material having a lower hardness than the pressing member 4 is disposed under the second substrate 3 with the protective sheet 2 interposed therebetween. Therefore, when a load is applied to the upper surface of the load equalizing substrate 5, the pressing member 4 sinks deeper than the second substrate 3 and presses the sensor portion SP of the fiber sensor, causing bending in the vicinity of the sensor portion SP. Let
Loss occurs in the sensor light transmitted to the fiber sensor due to the bending that occurs near the sensor portion SP of the fiber sensor. That is, when a load is applied to the load equalizing substrate 5, a loss is generated with respect to the light transmitted through the fiber sensor.

In the above, by setting the bending magnitude of the sensor part SP portion of the fiber sensor to change according to the magnitude of the load in a certain weight range, the loss of the sensor light according to the magnitude of the load. It can be configured to change.
Therefore, the weight measuring element is configured as described above, and the relationship between the magnitude of the load and the magnitude of the loss of the sensor light is examined in advance, so that the sensor light generated when the weight measuring object is placed is placed. The weight of the weight measurement object can be calculated from the magnitude of the loss.
Calculation of the weight of the weight measurement object from the data indicating the relationship between the magnitude of the load and the loss of the sensor light and the loss data of the sensor light at the time of measurement is, for example, a predetermined program for converting the loss data into a weight value. It can be realized by a computer incorporating

The weight measuring element of the present embodiment and the weight scale configured using the weight measuring element are configured to generate a loss with respect to the light transmitted through the fiber sensor according to the load applied to the load uniformizing substrate 5. Therefore, an inexpensive and highly accurate weighing scale can be realized.
Since the above scale is not electrically measured, it can be applied to, for example, a scale used in an explosion-proof facility.

  As described above, the weight measuring element of the present embodiment is preferably provided with the protective sheet 2 that protects the fiber sensor between the second substrate 3 and the pressing member 4 and the fiber sensor. It is possible to prevent the sensor from being damaged or destroyed when pressed by the pressing member 4.

Further, the weight measuring element of the present embodiment described above is provided in the opening 3a on the side wall portion in the direction orthogonal to the direction in which the fiber sensor is disposed in the vicinity of the sensor portion SP of the opening 3a of the second substrate 3. It is preferable that the notch part 3b which connects is formed. Thereby, the variation in the value of the loss obtained when the weight is light can be suppressed.
In FIG. 4, a + 2s, which is the distance from the end to the end of the cut portion 3b, is, for example, about 10 mm when a = 2 to 4 mm, and this size is reduced, that is, the length s is shortened. The effect of providing the cut portion is reduced. For example, by setting a + 2s to 6 mm or more, the effect of suppressing variation in the loss value obtained when the weight is light can be sufficiently obtained.

In the weight measuring element of the present embodiment, the height of the pressing member 4 is preferably substantially equal to the thickness of the second substrate 3. If they are equivalent, the loss of the sensor light can be sensed from when the weight is light.
If the height of the pressing member 4 is lower than the thickness of the second substrate 3, the loss of sensor light is not sensed by the weight until the pressing member 4 actually sinks until it presses the vicinity of the sensor portion SP of the fiber sensor. .
In addition, if the height of the pressing member 4 is higher than the thickness of the second substrate 3, a loss has already occurred at the time of zero weight, which may narrow the dynamic range of weight measurement.

  In the weight measuring element of the present embodiment, it is preferable that the pressing member 4 is made of metal, and the first substrate 1 and the second substrate 3 are made of silicone rubber. As described above, by constituting from materials having a high difference, the depression of the pressing member 4 when a load is applied can be realized, and a stable bend can be generated in the vicinity of the sensor portion of the sensor fiber. .

Second Embodiment FIGS. 6 and 7 are sectional views of a weight measuring element constituting a weighing scale according to this embodiment, and are sectional views corresponding to FIG. 4B of the first embodiment.
The weight measuring element according to the present embodiment is different from the pressing member 4 according to the first embodiment in the shape of the pressing member. Except for the above, the second embodiment is substantially the same as the first embodiment.

In the form shown in FIG. 6, the shape of the part which presses the part of the sensor part SP of the fiber sensor of the pressing member 4a is rounded like the first embodiment.
On the other hand, in the form shown in FIG. 7, the shape of the part which presses the part of sensor part SP of the fiber sensor of the press member 4b becomes a sharp shape.

  In addition to the above, the shape of the portion of the pressing member 4 that presses the portion of the sensor portion SP of the fiber sensor is a shape that causes bending in the vicinity of the sensor portion SP of the sensor fiber when a load is applied to the pressing member 4. There is no particular limitation.

  The weight measuring element of the present embodiment and the weight scale configured using the weight measuring element are configured to generate a loss with respect to the light transmitted through the fiber sensor according to the load applied to the load uniformizing substrate 5. Therefore, an inexpensive and highly accurate weighing scale can be realized.

Third Embodiment FIG. 8 is a cross-sectional view of a weight measuring element constituting a weigh scale according to the present embodiment, and is a cross-sectional view corresponding to FIG. 4C of the first embodiment.
The weight measuring element according to the present embodiment is different from the first embodiment in that the space of the opening 3a above the pressing member 4 is embedded with a sealant 6 made of silicone resin or the like. Except for the above, the second embodiment is substantially the same as the first embodiment.

  As described above, since the space of the opening 3 a above the pressing member 4 is embedded with the sealant 6, for example, when the pressing member 4 has a cylindrical shape, the load transmitted to the pressing member 4 is more uniform. The operation can be further stabilized.

  The weight measuring element of the present embodiment and the weight scale configured using the weight measuring element are configured to generate a loss with respect to the light transmitted through the fiber sensor according to the load applied to the load uniformizing substrate 5. Therefore, an inexpensive and highly accurate weighing scale can be realized.

A configuration other than the configuration described in the first embodiment may be employed as the sensor unit SP in the fourth embodiment .
9A and 9B are cross-sectional views in the longitudinal direction in the vicinity of the sensor part SP of the weight measuring element according to the present embodiment.
In FIG. 9A, the diameter bl of the core 31 of the hetero-core part 30 which is a light transmitting member constituting the sensor part SP is larger than the diameter al of the core 21 of the optical fiber (20a, 20b). .
In FIG. 9B, as the sensor part SP, a light transmitting member 30a which is not a hetero core part and is made of a material having a refractive index equivalent to the refractive index of the core 21 or the refractive index of the cladding 22 of the optical fiber (20a, 20b). Is joined to the middle part of the optical fiber (20a, 20b).

Other configurations are substantially the same as those in the first embodiment. Moreover, it is applicable to each of the above embodiments.
The weight measuring element of the above-described embodiment and the weight scale configured using the weight measuring element are configured to generate a loss with respect to the light transmitted through the fiber sensor according to the load applied to the load uniformizing substrate. Therefore, an inexpensive and highly accurate weighing scale can be realized.

Fifth Embodiment FIG. 10 is a schematic configuration diagram showing the configuration of a weighing scale according to the present embodiment.
For example, the weight measuring element WM is provided in the middle of the optical fiber (20a, 20b).
The optical fiber 20a is configured to branch the optical fiber 20c in the optical coupler 16, and a reflection part (mirror) 15 formed by vapor deposition of silver is provided at the end of the optical fiber 20b. The portion becomes the light incident end, and the end portion of the optical fiber 20c becomes the light emitting end.
A light source 11 such as a semiconductor light emitting diode or a semiconductor laser that emits sensor light is provided at the light incident end of the optical fiber 20a, and an optical multimeter that detects sensor light emitted from the light emitting end at the light emitting end of the optical fiber 20c. A light receiving unit 12 such as is provided.

Other configurations are substantially the same as those in the first embodiment. Moreover, it is applicable to each of the above embodiments.
The weight measuring element of the above-described embodiment and the weight scale configured using the weight measuring element are configured to generate a loss with respect to the light transmitted through the fiber sensor according to the load applied to the load uniformizing substrate. Therefore, an inexpensive and highly accurate weighing scale can be realized.

  In particular, since the sensor light reflected by the reflecting portion 15 passes through the sensor portion SP again, more light including information on mutual interference is measured as compared with light that has only passed in one direction. Weighing can be performed with high sensitivity.

Sixth Embodiment FIG. 11 is a schematic configuration diagram showing the configuration of a weighing scale according to the present embodiment.
For example, the weight measuring element WM is provided in the middle of the optical fiber (20a, 20b).
An OTDR (Optical time-domain reflectometer) device 70 is connected to the optical fiber 20a. The OTDR device 70 itself detects Rayleigh scattered light behind the sensor light incident from the OTDR device 70.

Other configurations are substantially the same as those in the first embodiment. Moreover, it is applicable to each of the above embodiments.
The weight measuring element of the above-described embodiment and the weight scale configured using the weight measuring element are configured to generate a loss with respect to the light transmitted through the fiber sensor according to the load applied to the load uniformizing substrate. Therefore, an inexpensive and highly accurate weighing scale can be realized.

Seventh Embodiment FIG. 12 is a schematic configuration diagram showing the configuration of a weighing scale according to the present embodiment.
For example, the first weight measuring element WM ₁ is provided in the middle of the optical fiber (20a, 20b), the second weight measuring element WM ₂ is provided in the middle of the optical fiber (20b, 20c), and the optical fiber ( 20c, the third weight measuring device WM ₃ is provided in the middle portion of the 20d). In other words, a plurality of weight measuring elements (WM _{1 to} WM ₃ ) are connected in series on one optical fiber.
An OTDR device 70 is connected to the optical fiber 20a. When sensor light is incident from the OTDR device 70, backward Rayleigh scattered light is generated in each of the plurality of weight measuring elements (WM _{1 to} WM ₃ ), and the OTDR device 70 detects this.

The configuration other than the above is substantially the same as that of the first embodiment, and the weight measuring elements (WM _{1 to} WM ₃ ) can be the same as those of the first embodiment, respectively. Moreover, it is applicable to each of the above embodiments.
The weight measuring element of the above-described embodiment and the weight scale configured using the weight measuring element are configured to generate a loss with respect to the light transmitted through the fiber sensor according to the load applied to the load uniformizing substrate. Therefore, an inexpensive and highly accurate weighing scale can be realized.
In particular, it is possible to simultaneously measure the weight with a plurality of weight measuring elements (WM _{1 to} WM ₃ ).

Eighth Embodiment FIG. 13 is a schematic configuration diagram showing the configuration of a weighing scale according to the present embodiment.
For example, the weight measuring element WM is provided in the middle of the optical fiber (20a, 20b).
A light source 11a that emits sensor light such as white light is provided at the light incident end of the optical fiber 20a, and a light receiving device such as an optical multimeter that detects sensor light emitted from the light emitting end at the light emitting end of the optical fiber 20b. A portion 12 is provided.
As sensor light, white light or the like can be used in addition to light of a single wavelength or a narrow wavelength region emitted from a semiconductor light emitting diode or a semiconductor laser.

Other configurations are substantially the same as those in the first embodiment. Moreover, it is applicable to each of the above embodiments.
The weight measuring element of the above-described embodiment and the weight scale configured using the weight measuring element are configured to generate a loss with respect to the light transmitted through the fiber sensor according to the load applied to the load uniformizing substrate. Therefore, an inexpensive and highly accurate weighing scale can be realized.

<Example>
The weighing scale according to the first embodiment was created, and the relationship between the load applied to the load uniformizing substrate and the loss generated in the sensor light was measured.
The results are shown in FIG. In the figure, the horizontal axis represents load (kg), and the vertical axis represents loss (dB).
As shown in FIG. 14, it can be configured to change so that the loss increases as the load increases.
Therefore, if the sensor light loss data is obtained when the measurement object is placed on the load uniformizing substrate, the load value can be calculated from FIG.

The present invention is not limited to the above description.
For example, the light source and the light receiving unit used are not limited to those described above, and various types can be used.
The optical fiber can be a multimode fiber or a single mode fiber.
In addition, various modifications can be made without departing from the scope of the present invention.

  The weight measuring element of the present invention and the weight scale using the same can be applied to, for example, a weight scale used in an explosion-proof facility.

FIG. 1 is a schematic configuration diagram of a weigh scale according to a first embodiment of the present invention. FIG. 2 is a perspective view of the weight measuring element of the present embodiment constituting the weighing scale according to the first embodiment of the present invention. FIG. 3 is an explanatory diagram illustrating the configuration of the weight measuring element shown in FIG. 4A is a plan view of the weight measuring element, FIG. 4B is a cross-sectional view taken along the line XX ′ in FIG. 4A, and FIG. 4C is the view in FIG. It is sectional drawing in YY '. FIG. 5A is a perspective view of the vicinity of the sensor part SP of the fiber sensor constituting the weight measuring element according to the first embodiment of the present invention, and FIG. 5B is a longitudinal sectional view of the vicinity of the sensor part SP. It is. FIG. 6 is a cross-sectional view of a weight measuring element constituting a weigh scale according to the second embodiment of the present invention. FIG. 7 is a cross-sectional view of a weight measuring element constituting a weigh scale according to the second embodiment of the present invention. FIG. 8 is a cross-sectional view of a weight measuring element constituting a weight scale according to the third embodiment of the present invention. FIGS. 9A and 9B are cross-sectional views in the longitudinal direction in the vicinity of the sensor portion SP of the weight measuring element according to the fourth embodiment of the present invention. FIG. 10 is a schematic configuration diagram showing the configuration of a weighing scale according to the fifth embodiment of the present invention. FIG. 11 is a schematic configuration diagram showing the configuration of a weighing scale according to a sixth embodiment of the present invention. FIG. 12 is a schematic configuration diagram showing the configuration of a weighing scale according to the seventh embodiment of the present invention. FIG. 13 is a schematic configuration diagram showing the configuration of a weighing scale according to the eighth embodiment of the present invention. FIG. 14 is a diagram illustrating the relationship between the load applied to the load uniformizing substrate and the loss generated in the sensor light according to the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... 1st board | substrate 2 ... Protection sheet 3 ... 2nd board | substrate 3a ... Opening part 3b ... Notch part 4 ... Pressing member 5 ... Load equalization board | substrate 6 ... Sealant 11, 11a ... Light source 12, 12a ... Light-receiving part 15 ... Reflection part DESCRIPTION OF SYMBOLS 16 ... Optical coupler 20a, 20b, 20c, 20d ... Optical fiber 21, 31 ... Core 22, 32 ... Cladding 30 ... Hetero core part 30a ... Light transmissive member 40 ... Interface 70 ... OTDR apparatus SP ... Sensor part W ... Leak WM, WM ₁ , WM ₂ , WM ₃ ... Weight measuring element

Claims (10)

A core and a clad provided on the outer periphery of the core, having a light transmission member that enables interaction with a part of the transmitted light to the outside, and light is incident on the incident end and the light is transmitted from the emission end An optical fiber that emits light that has passed through the member;
A first substrate disposed below the optical fiber so as to place at least a portion of the light transmitting member and a portion in the vicinity thereof;
A second substrate disposed above the optical fiber so that an opening is provided and at least a portion of the light transmitting member is located in a region of the opening;
A pressing member inserted into the opening and made of a material having a higher hardness than the first substrate and the second substrate;
A load uniformizing substrate provided on the second substrate and the pressing member,
The portion of the pressing member that presses the portion of the optical transmission member of the optical fiber has a shape that generates a bend in the vicinity of the optical transmission member of the optical fiber when a load is applied to the pressing member. The weight measuring element is configured to generate a loss corresponding to the load with respect to light transmitted through the optical fiber when a load is applied to the load uniformizing substrate. The weight measuring element according to claim 1, wherein a protective sheet for protecting the optical fiber is provided between the second substrate, the pressing member, and the optical fiber. The notch part connected to the said opening part is formed in the side wall part of the direction orthogonal to the direction where the said optical fiber is arrange | positioned in the vicinity of the part of the said light transmissive member of the said opening part. The weight measuring element described. The weight measuring element according to claim 1, wherein a height of the pressing member is substantially equal to a thickness of the second substrate. The weight measuring element according to claim 1, wherein a portion of the pressing member that presses the light transmitting member of the optical fiber is rounded or pointed. The weight measuring element according to claim 1, wherein the pressing member is made of metal or silicone rubber, and the first substrate and the second substrate are made of silicone rubber. The weight measuring element according to claim 1, wherein the light transmitting member is a hetero core portion having a core diameter different from a core diameter of the optical fiber. The weight measuring element according to claim 1, wherein the light transmissive member is a light transmissive member having a refractive index equivalent to a refractive index of a core of the optical fiber or a refractive index of a clad. A gravity measuring element comprising an optical fiber;
A light source provided at an incident end of the optical fiber;
A light receiving portion provided at the output end of the optical fiber,
The weight measuring element is
A core and a clad provided on the outer periphery of the core, having a light transmission member that enables interaction with a part of the transmitted light to the outside, and light is incident on the incident end and the light is transmitted from the emission end An optical fiber that emits light that has passed through the member;
A first substrate disposed below the optical fiber so as to place at least a portion of the light transmitting member and a portion in the vicinity thereof;
A second substrate disposed above the optical fiber so that an opening is provided and at least a portion of the light transmitting member is located in a region of the opening;
A pressing member inserted into the opening and made of a material having a higher hardness than the first substrate and the second substrate;
A load uniformizing substrate provided on the second substrate and the pressing member,
The portion of the pressing member that presses the portion of the optical transmission member of the optical fiber has a shape that generates a bend in the vicinity of the optical transmission member of the optical fiber when a load is applied to the pressing member. The weight scale is configured to generate a loss corresponding to the load with respect to the light transmitted through the optical fiber when a load is applied to the load equalizing substrate. The weighing scale according to claim 9, wherein the light source is a semiconductor light emitting diode, a semiconductor laser, or white light.

Images