WO2022176588A1 - 荷重センサ - Google Patents
荷重センサ Download PDFInfo
- Publication number
- WO2022176588A1 WO2022176588A1 PCT/JP2022/003600 JP2022003600W WO2022176588A1 WO 2022176588 A1 WO2022176588 A1 WO 2022176588A1 JP 2022003600 W JP2022003600 W JP 2022003600W WO 2022176588 A1 WO2022176588 A1 WO 2022176588A1
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- WIPO (PCT)
- Prior art keywords
- dielectric
- load
- load sensor
- elastic body
- capacitance
- Prior art date
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Images
Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
- G01L1/14—Measuring force or stress, in general by measuring variations in capacitance or inductance of electrical elements, e.g. by measuring variations of frequency of electrical oscillators
- G01L1/142—Measuring force or stress, in general by measuring variations in capacitance or inductance of electrical elements, e.g. by measuring variations of frequency of electrical oscillators using capacitors
- G01L1/148—Measuring force or stress, in general by measuring variations in capacitance or inductance of electrical elements, e.g. by measuring variations of frequency of electrical oscillators using capacitors using semiconductive material, e.g. silicon
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
- G01L1/14—Measuring force or stress, in general by measuring variations in capacitance or inductance of electrical elements, e.g. by measuring variations of frequency of electrical oscillators
- G01L1/142—Measuring force or stress, in general by measuring variations in capacitance or inductance of electrical elements, e.g. by measuring variations of frequency of electrical oscillators using capacitors
Definitions
- the present invention relates to a load sensor that detects an externally applied load based on changes in capacitance.
- Patent Literature 1 describes a force detection device that includes a main substrate, electrodes, an insulating layer, a displacement generator, and an elastic conductive layer.
- the electrodes are formed on the upper surface of the main substrate and covered with an insulating layer.
- the displacement generator includes a fixed portion, a flexible portion, and an action portion, and the action portion is connected to the fixed portion fixed to the main substrate via the flexible portion.
- the elastic conductive layer is formed on the bottom surface of the action portion, and has a rough surface having a large number of uneven structures on the bottom surface.
- the contact state between the upper surface of the insulating layer and the rough surface of the elastic conductive layer changes, and the capacitance based on the electrodes and the elastic conductive layer changes.
- the applied force (load) is detected by electrically detecting the magnitude of the capacitance.
- the capacitance-type load sensor In a capacitance-type load sensor, it is preferable that the capacitance changes linearly according to the load. That is, if the capacitance linearly changes according to the load, the process for calculating the load from the magnitude of the capacitance becomes extremely simple. For this reason, it is preferable that the capacitance-type load sensor can ensure as wide a range as possible in which the capacitance linearly changes according to the load.
- the range in which the capacitance based on the electrodes and the elastic conductive layer linearly changes according to the load is narrow. Therefore, with this configuration, it is difficult to detect the load with a simple process over a wide dynamic range.
- an object of the present invention is to provide a load sensor capable of expanding the range in which the capacitance linearly changes according to the load.
- a load sensor includes an electrode, a dielectric arranged on the surface of the electrode, and a conductive elastic body arranged to face the dielectric and having electrical conductivity.
- a plurality of protrusions are formed on the dielectric-side surface of the conductive elastic body, and the thickness of the dielectric decreases in the planar direction from the initial contact position with the conductive elastic body.
- the load sensor in the initial state where no load is applied, only some projections included in the initial contact position contact the dielectric. After that, when a load is applied, the protrusions come into contact with the dielectric in order from the initial contact position as the load increases, and the number of protrusions in contact with the dielectric increases. Also, the protrusion shrinks as the load increases after contacting the dielectric. Thereby, the contact area between the protrusion and the dielectric increases with increasing load.
- the number of projections in contact with the dielectric and the contact area between the projections and the dielectric change with the load, so that the capacitance between the electrode and the conductive elastic body changes with the load. Change.
- the thickness of the dielectric decreases in the planar direction from the initial contact position, the change in capacitance due to the thickness of the dielectric increases as the load increases.
- the range in which the relationship between the load and the capacitance is linear can be extended to a higher load range. Therefore, according to the load sensor according to this aspect, it is possible to widen the range in which the capacitance linearly changes according to the load.
- FIG. 1 is an exploded perspective view schematically showing the configuration of a load sensor according to the embodiment.
- FIG. 2(a) is a side view schematically showing the state of the load sensor in the initial state according to the embodiment.
- FIGS. 2B and 2C are side views schematically showing states of the load sensor when a load is applied, respectively, according to the embodiment.
- FIG. 3A is a diagram for explaining simulation conditions according to the embodiment.
- FIG. 3B is a graph showing simulation results according to the embodiment.
- FIG. 4A is a diagram for explaining simulation conditions according to the embodiment.
- FIG. 4B is a graph showing simulation results according to the embodiment.
- FIG. 5A is a perspective view schematically showing the configuration of electrodes and dielectrics according to Modification 1.
- FIG. 5B is a perspective view schematically showing the configuration of electrodes and dielectrics according to Modification 2.
- FIG. 6A is a perspective view schematically showing the configuration of an electrode, a dielectric, and a conductive elastic body according to Modification 3.
- FIG. 6B is a side view schematically showing the state of the load sensor in the initial state according to Modification 3.
- FIG. 7A is a plan view schematically showing the configuration of a conductive elastic body according to Modification 4.
- FIG. 7(b) is a perspective view schematically showing the configuration of an electrode, a dielectric, and a conductive elastic body according to Modification 5.
- FIG. 8(a) is a side view schematically showing the configuration of a load sensor according to another modification.
- FIG. 8(a) is a side view schematically showing the configuration of a load sensor according to another modification.
- FIG. 8(b) is a graph showing simulation results according to a modification of FIG. 8(a).
- FIG. 9(a) is a side view schematically showing the configuration of a load sensor according to another modification.
- FIG.9(b) is a graph which shows the simulation result based on the modification of Fig.9 (a).
- FIG. 10(a) is a side view schematically showing the configuration of a load sensor according to another modification.
- FIG. 10(b) is a graph showing simulation results according to a modification of FIG. 10(a).
- FIG. 11(a) is a side view schematically showing the configuration of a load sensor according to another modification.
- FIG. 11(b) is a graph showing simulation results according to a modification of FIG. 11(a).
- FIG. 11(a) is a side view schematically showing the configuration of a load sensor according to another modification.
- FIG. 11(b) is a graph showing simulation results according to a modification of FIG. 11(a).
- FIG. 12(a) is a side view schematically showing the configuration of a load sensor according to another modification.
- FIG. 12(b) is a graph showing simulation results according to a modification of FIG. 12(a).
- FIG. 13(a) is a side view schematically showing the configuration of a load sensor according to another modification.
- FIG. 13(b) is a graph showing simulation results according to a modification of FIG. 13(a).
- the present invention can be applied to an input unit for performing input according to the applied load.
- the present invention includes an input unit of an electronic device such as a PC keyboard, an input unit of a game controller, a surface layer for a robot hand to detect an object, an input for inputting volume, wind volume, light intensity, temperature, etc. parts, input parts of wearable devices such as smartwatches, input parts of hearable devices such as wireless earphones, input parts of touch panels, input parts for adjusting the amount of ink in electronic pens, and adjusting the amount of light and colors in penlights.
- the present invention can be applied to an input unit for controlling the sound, an input unit for adjusting the amount of light in shining clothing, and an input unit for adjusting the volume of a musical instrument.
- the following embodiments are load sensors typically provided in such devices. Such a load sensor is called a “capacitive pressure sensor element”, a “capacitive pressure detection sensor element”, a “pressure sensitive switch element”, or the like.
- a load sensor is called a "capacitive pressure sensor element”, a “capacitive pressure detection sensor element”, a “pressure sensitive switch element”, or the like.
- the following embodiment is one embodiment of the present invention, and the present invention is not limited to the following embodiment.
- the Z-axis direction is the height direction of the load sensor 1 .
- FIG. 1 is an exploded perspective view schematically showing the configuration of the load sensor 1.
- the load sensor 1 includes substrates 10 and 20, a conductive elastic body 30, an electrode 40, and a dielectric 50.
- the substrates 10 and 20 are rectangular parallelepiped plates having flexibility and a predetermined thickness.
- the substrate 10 is a support member on which the conductive elastic body 30, the electrode 40 and the dielectric 50 are placed.
- Substrates 10 and 20 are, for example, at least one resin material selected from polyethylene terephthalate, polycarbonate, polyimide, and the like.
- the top and bottom surfaces of the substrates 10, 20 are parallel to the XY plane.
- the substrates 10 and 20 have the same shape and size in plan view.
- the conductive elastic body 30 is a conductive elastic member and has a rectangular shape in plan view.
- the conductive elastic body 30 is composed of a resin material and conductive filler dispersed therein, or a rubber material and conductive filler dispersed therein.
- the resin material is, for example, a styrene-based resin, a silicone-based resin (such as polydimethylpolysiloxane (PDMS)), an acrylic-based resin, a rotaxane-based resin, a urethane-based resin, or the like. .
- the rubber material is, for example, silicone rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, chloroprene rubber, nitrile rubber, polyisobutylene, ethylene propylene rubber, chlorosulfonated polyethylene, At least one rubber material selected from acrylic rubber, fluororubber, epichlorohydrin rubber, and urethane rubber.
- Conductive fillers used in the conductive elastic body 30 include, for example, Au (gold), Ag (silver), Cu (copper), C (carbon), ZnO (zinc oxide), In 2 O 3 (indium oxide (III) ) and SnO 2 (tin(IV) oxide).
- a plurality of projections 31 protruding in the Z-axis negative direction are formed in a grid pattern on the surface of the conductive elastic body 30 (surface on the Z-axis negative side). That is, on the surface of the conductive elastic body 30, a plurality of protrusions 31 are formed side by side in the Y-axis direction, and a plurality of such rows are arranged in the X-axis direction.
- the distance between the projections 31 in the Y-axis direction is constant, and the distance between the projections 31 in the X-axis direction is also constant.
- the thickness of the conductive elastic body 30 is constant except for the projection 31 portion.
- protrusion 31 decreases as it progresses in the Z-axis negative direction.
- protrusion 31 has a spherical shape.
- the shape and size of each protrusion 31 are the same as each other.
- a total of 200 projections 31 of 10 vertical and 20 horizontal are formed on the surface of the conductive elastic body 30 .
- Conductive wires (not shown) for electrically connecting a device outside the load sensor 1 and the conductive elastic body 30 are installed on the conductive elastic body 30 .
- the electrode 40 is made of a conductive metal material.
- the material of the electrode 40 is selected from, for example, In2O3 , ZnO and/or SnO2.
- the electrode 40 is a rectangular plate-like member in plan view.
- the electrodes are slightly smaller than the substrates 10 and 20 in plan view.
- the electrode 40 and the conductive elastic body 30 have the same shape and size in plan view.
- the dielectric 50 is made of an electrically insulating material.
- the material of dielectric 50 is selected from, for example, polypropylene resin, polyethylene terephthalate resin, polyimide resin, polyphenylene sulfide resin, Al 2 O 3 and Ta 2 O 5 .
- Dielectric 50 is formed on the surface of electrode 40 by insert molding, for example.
- the dielectric 50 has a shape whose thickness changes only in one direction (Y-axis direction). Specifically, the dielectric 50 has a cylindrical shape protruding toward the conductive elastic body 30 . The thickness of the dielectric 50 is greatest at an intermediate position in the Y-axis direction and gradually decreases toward both ends in the Y-axis direction.
- the conductive elastic body 30 is placed on the upper surface of the substrate 10, and the structure composed of the dielectric 50 and the electrode 40 is mounted on the conductive elastic body so that the dielectric 50 faces the conductive elastic body 30. 30 is overlaid on top. Then, the substrate 20 is put on the electrode 40, and the periphery of the substrate 20 is installed on the substrate 10 by the installation member. Thus, the load sensor 1 is completed.
- FIG. 2(a) is a side view schematically showing the state of the load sensor 1 in the initial state (state in which no load is applied).
- the number of projections 31 arranged in the Y-axis direction is seven.
- 2B and 2C are side views schematically showing the state of the load sensor 1 when a load is applied.
- the initial contact position P0 is the position at which the projection 31 and the dielectric 50 are in contact in the initial state where no load is applied.
- the thickness of the dielectric 50 is the largest at the middle position of the dielectric 50 in the Y-axis direction, and the heights of all the protrusions 31 are the same.
- the protrusion 31 and the dielectric 50 are in contact. That is, the intermediate position of the dielectric 50 in the Y-axis direction is the initial contact position P0.
- FIG. 2(c) shows a state in which the load is increased from that in FIG. 2(b).
- the projection 31 shrinks as the load increases after coming into contact with the dielectric 50 .
- the contact area S0 between the projection 31 and the dielectric 50 increases as the load increases.
- the number of protrusions 31 in contact with the dielectric 50 and the contact area S0 between the protrusions 31 and the dielectric 50 change with the load, so that the contact between the electrode 40 and the conductive elastic body 30 is increased. changes with load.
- This capacitance is proportional to the total contact area between protrusion 31 and dielectric 50 and inversely proportional to the thickness of dielectric 50 .
- the thickness of the dielectric 50 decreases in the planar direction from the initial contact position P0, the thickness of the dielectric 50 at the position where the protrusion 31 newly contacts gradually decreases as the load increases. Therefore, the more the load increases, the greater the increase in capacitance that occurs at the newly touched position. That is, the change in capacitance due to the thickness of the dielectric 50 increases as the load increases. As a result, the range in which the relationship between the load and the capacitance is linear can be extended to a higher load range.
- FIG. 3(a) is a diagram for explaining simulation conditions for Verification 1.
- protrusions 31 were arranged in a row in the Y-axis direction. Only one row of protrusions 31 was set.
- the projection 31 was semicircular and the height H1 of the projection 31 was set to 0.06 mm.
- the pitch P1 of the protrusions 31 was set to 0.3 mm, and the length L1 of the conductive elastic body 30 in the Y-axis direction was set to 1.5 mm.
- the five protrusions 31 were evenly arranged so that the center of the central protrusion 31 was located at the intermediate position of the conductive elastic body 30 in the Y-axis direction.
- the length of the electrode 40 in the Y-axis direction was also set to 1.5 mm, like the length L1 of the conductive elastic body 30.
- the dielectric 50 has a cylindrical shape with a constant curvature and is set to extend from one end of the electrode 40 in the Y-axis direction to the other end.
- the cylindrical generatrix is parallel to the X-axis.
- the dielectric 50 was arranged so that the thickest position of the dielectric 50 coincided with the middle position of the electrode 40 in the Y-axis direction. Therefore, in the Y-axis direction, the middle position of the conductive elastic body 30 and the middle position of the electrode 40 match.
- the height H2 (maximum thickness) of the dielectric 50 is varied to obtain the load applied between the conductive elastic body 30 and the electrode 40 and the static electricity between the conductive elastic body 30 and the electrode 40.
- the relationship with electric capacity was determined by simulation.
- the curve shape (curvature) of the surface of the dielectric 50 was changed so that the dielectric 50 spreads over the entire upper surface of the electrode 40 according to the change in the height H2.
- As the height H2 of the dielectric 50 four types of 0 mm, 0.01 mm, 0.03 mm, and 0.06 mm are set.
- the case where the height H2 is 0 mm corresponds to the case where the surface of the dielectric 50 is flat.
- FIG. 3(b) is a graph showing the simulation results of Verification 1.
- the vertical and horizontal axes in FIG. 3B are each standardized by a predetermined value.
- FIG. 4(a) is a diagram for explaining simulation conditions for verification 2.
- FIG. 4(a) is a diagram for explaining simulation conditions for verification 2.
- the height H1 and pitch P1 of the protrusions 31 were set to 0.06 mm and 0.3 mm, respectively, as in Verification 1 above. Also, the length L1 of the conductive elastic body 30 and the electrode 40 was set to 1.5 mm, as in Verification 1 above. Other conditions were set in the same manner as in Verification 1 above.
- the height H2 (maximum thickness) of the dielectric 50 is varied to obtain the load applied between the conductive elastic body 30 and the electrode 40 and the static electricity between the conductive elastic body 30 and the electrode 40.
- the relationship with electric capacity was determined by simulation.
- the curve shape (curvature) of the surface of the dielectric 50 was changed so that the dielectric 50 spreads over the entire upper surface of the electrode 40 according to the change in the height H2.
- 0.09 mm was added in addition to 0.01 mm, 0.03 mm, and 0.06 mm as in Verification 1 above.
- FIG. 4(b) is a graph showing the simulation results of Verification 2.
- the vertical and horizontal axes in FIG. 4(b) are normalized by predetermined values.
- the characteristics when the height H2 of the dielectric 50 is 0.09 mm are substantially the same as when the height H2 of the dielectric 50 is 0.06 mm. Also, referring to the verification results in FIG. 3B, when the height H2 of the dielectric 50 is 0.06 mm and 0.09 mm, the characteristics are better than when the surface of the dielectric 50 is flat. It turns out that it decreases. From this, when the height H2 of the dielectric 50 is 0.06 mm or more, which is the same as the height H1 of the protrusion 31, the electrostatic capacitance with respect to the load is It was found that the change in
- At least the height H2 (maximum change in thickness) of the dielectric 50 should be equal to the height H1 (protrusion amount) of the protrusion 31. ) should be set smaller than More preferably, the height H2 (maximum change in thickness) of the dielectric 50 is half or less than the height H1 (protrusion amount) of the protrusion 31, as can be seen from the simulation results of FIG. 4(b). .
- the number of protrusions 31 in contact with the dielectric 50 and the contact area S0 between the protrusions 31 and the dielectric 50 change with the load, so that the contact between the electrode 40 and the conductive elastic body 30 is increased. changes with load.
- the thickness of the dielectric 50 is reduced in the planar direction from the initial contact position P0, the change in capacitance due to the thickness of the dielectric 50 increases as the load increases.
- the range in which the relationship between the load and the capacitance is linear can be extended to a higher load range. Therefore, the range in which the capacitance linearly changes according to the load can be widened.
- the dielectric 50 has a convex shape toward the conductive elastic body 30. As shown in FIG. As a result, it is possible to efficiently increase the number of protrusions 31 that start contacting the dielectric 50 by subsequent load application while limiting the number of protrusions 31 that come into contact at the initial contact position P0. Therefore, the change in capacitance at the start of load application can be smoothly increased.
- the surface of the dielectric 50 on the side of the conductive elastic body 30 is curved. That is, in the present embodiment, the dielectric 50 has a shape whose thickness changes only in one axial direction, and more specifically, the dielectric 50 has a cylindrical shape. As a result, the contact area S0 between the projection 31 and the dielectric 50 can be smoothly changed when a load is applied, and the thickness of the dielectric 50 at the contact position can be smoothly changed. Therefore, the relationship between the load and the capacitance can be brought closer to linearity more smoothly.
- the protrusion 31 protrudes in a curved shape.
- the contact area S0 between the projection 31 and the dielectric 50 can be smoothly changed when the load is applied. Therefore, the relationship between the load and the capacitance can be brought closer to linearity more smoothly.
- the maximum change amount (height H2) of the thickness of the dielectric 50 is preferably smaller than the protrusion amount (height H1) of the protrusion 31.
- the plurality of protrusions 31 are arranged in at least one row, and the dielectric 50 varies in thickness in the direction in which the protrusions 31 are arranged. Moreover, as shown in FIG. 3A, the plurality of protrusions 31 are arranged at regular intervals (pitch P1). Accordingly, the protrusions 31 can be brought into contact with the dielectric 50 sequentially in the alignment direction according to the application of the load, and the change in capacitance with respect to the load can be smoothly approximated to linear.
- the configuration of the load sensor 1 can be modified in various ways other than the configuration shown in the above embodiment.
- the dielectric 50 has a cylindrical shape whose thickness changes only in the Y-axis direction.
- the shape may be such that the thickness changes not only in the axial direction but also in the X-axis direction.
- the dielectric 50 may have a spherical shape with the maximum thickness at the center of the electrode 40 .
- the position where the thickness is maximum is the initial contact position P0 between the projection 31 and the dielectric 50 in the initial state where no load is applied, and the projection 31 and the dielectric 50 contact each other according to the application of the load. , radially spreads from the initial contact position P0.
- dielectric 50 may be divided into a plurality of regions, and the thickness of dielectric 50 may vary in the plane direction in each divided region.
- the dielectric 50 may be divided into two in the Y-axis direction, and the thickness of the dielectric 50 in each divided region A1 may vary in the Y-axis direction.
- the shape of the dielectric 50 in each divided area A1 is set to a cylindrical shape.
- the number of protrusions 31 in contact with the dielectric 50 and the contact area between the dielectric 50 and the protrusions 31 change according to the application of the load.
- the thickness of the dielectric 50 changes.
- the number of divisions of the dielectric 50 is not limited to two, and the dielectric 50 may be divided into other numbers.
- the thickness of the dielectric 50 may be set so as to vary in the planar direction in each divided region.
- the dielectric 50 may be divided not only in the Y-axis direction but also in the X-axis direction.
- the shape of the dielectric 50 set in each divided region is not limited to a cylindrical shape, and may be, for example, a shape in which the thickness changes in two directions as shown in FIG. 5(a). .
- the configuration of the dielectric 50 is not limited to the configuration in which the central thickness in the Y-axis direction is the thickest.
- the upper surface of the dielectric 50 is a plane parallel to the XY plane (a plane perpendicular to the direction in which the load is applied). good too.
- the upper surface of the dielectric 50 with which the central projection 31 in the Y-axis direction abuts may be a plane parallel to the XY plane.
- the range A1 can be set to a width that covers the contact area of the center projection 31 when the center projection 31 is most compressed by the load.
- Range A1 is, for example, circular in plan view.
- the top surface of the dielectric 50 other than the range A1 can be set to the same shape as in the above embodiment.
- FIG. 8(b) is a graph showing the results of verification by simulation of the relationship between the load and the capacitance for the configuration of FIG. 8(a).
- the height H1, pitch P1, and length L1 were set in the same way as Verification 1 in the above embodiment.
- the height H2 is defined as the height from the top surface of the electrode 40 (the bottom surface of the dielectric 50) to the plane of the range A1.
- the height H2 is set to 0.03 mm.
- Verification 1 above assuming a case where five protrusions 31 are arranged in one line in the Y-axis direction, only one line of protrusions 31 is set.
- the protrusions 31 are semicircular.
- the relationship between the load and the capacitance was obtained by simulation for the range of the load until the capacitance was substantially saturated in the configuration of FIG. 8(a).
- the relationship between the load and the capacitance was obtained by simulation when the entire range of the upper surface of the dielectric 50 was a plane parallel to the XY plane.
- ranges A2 and A3 of the upper surface of the dielectric 50 with which the projections 31 other than the central projection 31 in the Y-axis direction are in contact are further defined as a plane parallel to the XY plane. It may be. Also in this case, the ranges A2 and A3 can be set to a width that covers the contact area of the opposing protrusions 31 when the protrusions 31 are most compressed by the load.
- the top surface of the dielectric 50 other than the ranges A1, A2, A3 can be set to the same shape as in the above embodiment.
- FIG. 9(b) is a graph showing the results of verification by simulation of the relationship between the load and the capacitance for the configuration of FIG. 9(a).
- the simulation conditions other than the height H2 were set in the same way as in FIG. 8(b).
- the height H2 is defined as the height from the upper surface of the electrode 40 (the lower surface of the dielectric 50) to each plane of the ranges A1, A2, and A3.
- the height H2 to the plane of the range A1 is set to 0.03 mm
- the height H2 to the plane of the range A2 is set to 0.02 mm
- the height H2 to the plane of the range A3 is It was set to 0.01 mm.
- the upper surface of the dielectric 50 may be formed in a concave shape with the largest thickness at both ends in the Y-axis direction and the smallest thickness at the intermediate position in the Y-axis direction.
- the top surface of the dielectric 50 can be formed in a cylindrical plane with the generatrix parallel to the X-axis.
- FIG. 10(b) is a graph showing the results of verification by simulation of the relationship between the load and the capacitance for the configuration of FIG. 10(a).
- the simulation conditions other than the height H2 were set in the same way as in FIG. 8(b).
- the height H2 is defined with reference to the upper surface of the electrode 40 (the lower surface of the dielectric 50).
- the height H2 of the dielectric 50 from both ends in the Y-axis direction to the upper surface was set at 0.03 mm, and the height H2 from the center of the dielectric 50 in the Y-axis direction to the upper surface was set at 0.0009 mm.
- the range A1 of the upper surface of the dielectric 50 with which the central protrusion 31 in the Y-axis direction abuts may be a plane parallel to the XY plane. Also in this case, the range A1 can be set to a width that covers the contact area of the opposing protrusions 31 when the protrusions 31 are most compressed by the load.
- the upper surface of the dielectric 50 other than the range A1 can be set to the same cylindrical surface as in FIG. 10(a).
- FIG. 11(b) is a graph showing the results of verification by simulation of the relationship between the load and the capacitance for the configuration of FIG. 11(a).
- the simulation conditions other than the height H2 were set in the same way as in FIG. 8(b).
- the height H2 is defined with reference to the upper surface of the electrode 40 (the lower surface of the dielectric 50).
- the height H2 to the upper surface of both ends of the dielectric 50 in the Y-axis direction was set to 0.03 mm, and the height H2 to the upper surface of the range A1 was set to 0.0009 mm.
- ranges A2 and A3 of the upper surface of the dielectric 50 with which the projections 31 other than the central projection 31 in the Y-axis direction abut are also planes parallel to the XY plane.
- the ranges A2 and A3 can be set to a width that covers the contact area of the opposing protrusions 31 when the protrusions 31 are most compressed by the load.
- the upper surface of the dielectric 50 other than the ranges A1, A2, A3 can be set to the same cylindrical surface as in FIG. 10(a).
- FIG. 12(b) is a graph showing the results of verification by simulation of the relationship between the load and the capacitance for the configuration of FIG. 12(a).
- the simulation conditions other than the height H2 were set in the same way as in FIG. 8(b).
- the height H2 is defined as the height from the upper surface of the electrode 40 (the lower surface of the dielectric 50) to each plane of the ranges A1, A2, and A3.
- the height H2 to the plane of range A1 is set to 0.0009 mm
- the height H2 to the plane of range A2 is set to 0.01 mm
- the height H2 to the plane of range A3 is set to It was set to 0.02 mm.
- the height H3 to the upper surface of the dielectric 50 at both ends in the Y-axis direction was set to 0.03 mm.
- a protrusion 51 is formed on the upper surface of the dielectric 50 facing the protrusion 31.
- the thickness of the dielectric 50 can be changed to It may decrease in the planar direction from the initial contact position between the dielectric 50 and the conductive elastic body 30 .
- Projection 51 is, for example, hemispherical. In this case, the protrusion 51 may not be formed at a position facing the predetermined protrusion 31 . In FIG. 13(a), no protrusion 51 is formed at a position facing the center protrusion 31 in the Y-axis direction.
- FIG. 13(b) is a graph showing the results of verification by simulation of the relationship between the load and the capacitance for the configuration of FIG. 13(a).
- the simulation conditions other than the height H2 were set in the same way as in FIG. 8(b).
- the height H2 is defined with reference to the upper surface of the electrode 40 (the lower surface of the dielectric 50).
- the height H2 to the apex of the protrusions 51 on both ends in the Y-axis direction was set to 0.03 mm, and the height H2 to the apex of the inner protrusions 51 was set to 0.02 mm.
- the height H2 to the upper surface of the dielectric 50 at the position facing the central protrusion 31 was set to 0.01 mm.
- the simulation result of FIG. 8B was compared with the simulation result of FIG. 9B, the simulation result of FIG. It had a wide dynamic range. It is considered that this is because the protrusion 31 deforms more efficiently in the Z-axis direction when pressed against a plane parallel to the XY plane. From this, it can be said that the upper surface of the dielectric 50 at the position facing the projection 31 is preferably not a plane perpendicular to the load application direction in order to secure a wider dynamic range.
- the simulation result of FIG. 10A was remarkably wide. It was found that this is because, in the structure of FIG. 10A, the upper surfaces of the dielectrics 50 at both ends in the Y-axis contact the lower surfaces of the conductive elastic bodies 30 other than the projections 31 due to the increased load. From this, it can be said that the upper surface of the dielectric 50 preferably has a shape in which the center in the Y-axis direction is high and both ends in the Y-axis direction are low in order to ensure a wider dynamic range.
- the five protrusions 31 are arranged in the Y-axis direction.
- a plurality of electrodes 40 and dielectrics 50 may be arranged and spread in the X-axis direction accordingly.
- the configurations of Modifications 1 to 4 may be applied to the modifications shown in FIGS. 8(a) to 13(b).
- the dielectric 50 may have a configuration in which the thickness is greatest at one end in the Y-axis direction and the thickness gradually decreases toward the other end in the Y-axis direction.
- the surface of the dielectric 50 is not limited to a curved surface, and may be a plane inclined at a predetermined angle with respect to the plane of the electrode 40 on the dielectric 50 side.
- the plurality of projections 31 are arranged on the surface of the conductive elastic body 30 so as to be arranged at regular intervals in the X-axis direction and the Y-axis direction.
- a plurality of protrusions 31 are arranged at regular intervals in the X-axis direction and the Y-axis direction. May be omitted.
- the positions of the columns on both sides of the omitted column are the initial contact positions P0.
- the positions of the projections 31 are shifted by half a pitch on the Y axis. direction may be shifted.
- projections 31 may be arranged radially from the center of conductive elastic body 30 .
- the protrusion 31 has a hemispherical shape, but the shape of the protrusion 31 is not limited to this.
- the shape of the protrusion 31 may be a shape in which the apex of a hemispherical surface is notched in a plane parallel to the XY plane.
- the shape of the protrusion 31 may be a cone or a pyramid, or a shape in which the apex of the cone or pyramid is cut in a plane parallel to the XY plane. It is preferable that the protrusion 31 has a shape in which the cross-sectional area decreases toward the tip.
- the projection 31 may be a long ridge in the X-axis direction.
- the projection 31 may be a semi-cylindrical projection. Also in this case, the same effects as in the above embodiment can be obtained.
- the projections 31 may have different shapes and heights, and the pitch of the projections 31 may not be constant.
- the height and pitch of the projections 31 may be adjusted so that the change in capacitance with respect to load is more linear.
- the change in thickness of dielectric 50 may be adjusted so that the change in capacitance with respect to load is more linear.
- one conductive elastic body 30 is arranged for one electrode 40, but this is not restrictive. may be arranged side by side in the XY plane with a spacing of .
- the external device detects changes in capacitance based on the plurality of conductive elastic bodies 30, adds the obtained plurality of capacitances, and detects changes in the overall capacitance. . Then, the external device detects the load applied to the load sensor 1 based on the change in the overall capacitance.
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Abstract
Description
発明者らは、上記実施形態の構成による効果を、シミュレーションにより検証した。
次に、発明者らは、荷重に対する静電容量の変化の線形性および感度を効果的に高め得る誘電体50の高さH2の範囲を、シミュレーションにより検証した。
本実施形態によれば、以下の効果が奏される。
荷重センサ1の構成は、上記実施形態に示した構成以外に、種々の変更が可能である。
30 導電弾性体
31 突起
40 電極
50 誘電体
A1 分割領域
P0 初期接触位置
Claims (12)
- 電極と、
前記電極の表面に配置された誘電体と、
前記誘電体に対向して配置され、導電性を有する導電弾性体と、を備え、
前記導電弾性体の前記誘電体側の表面には、複数の突起が形成され、
前記誘電体は、前記導電弾性体との初期接触位置から平面方向に厚みが減少している、
ことを特徴とする荷重センサ。
- 請求項1に記載の荷重センサにおいて、
前記誘電体は、前記導電弾性体に向かって凸の形状である、
ことを特徴とする荷重センサ。
- 請求項1に記載の荷重センサにおいて、
前記誘電体は、前記導電弾性体から離れる方向に凹んだ形状である、
ことを特徴とする荷重センサ。
- 請求項1ないし3の何れか一項に記載の荷重センサにおいて、
前記導電弾性体側の前記誘電体の表面は、曲面形状である、
ことを特徴とする荷重センサ。
- 請求項1ないし4の何れか一項に記載の荷重センサにおいて、
前記誘電体は、一軸方向のみに厚みが変化する形状である、
ことを特徴とする荷重センサ。
- 請求項5に記載の荷重センサにおいて、
前記誘電体は、シリンドリカル形状である、
ことを特徴とする荷重センサ。
- 請求項1ないし3の何れか一項に記載の荷重センサにおいて、
前記導電弾性体側の前記誘電体の表面には、前記突起に対向する位置に、荷重の付与方向に垂直な平面が形成されている、
- 請求項1ないし7の何れか一項に記載の荷重センサにおいて、
前記誘電体は、複数に分割され、
各分割領域において、前記誘電体の厚みが平面方向に変化している、
ことを特徴とする荷重センサ。
- 請求項1ないし8の何れか一項に記載の荷重センサにおいて、
前記突起は、曲面状に突出している、
ことを特徴とする荷重センサ。
- 請求項1ないし9の何れか一項に記載の荷重センサにおいて、
前記誘電体の厚みの最大変化量は、前記突起の突出量より小さい、
ことを特徴とする荷重センサ。
- 請求項1ないし10の何れか一項に記載の荷重センサにおいて、
前記複数の突起は、少なくとも一列に並んで配置され、
前記誘電体は、前記突起の並び方向に厚みが変化している、
ことを特徴とする荷重センサ。
- 請求項11に記載の荷重センサにおいて、
前記複数の突起は、一定間隔で並んでいる、
ことを特徴とする荷重センサ。
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CN202280015411.0A CN116917706A (zh) | 2021-02-17 | 2022-01-31 | 负荷传感器 |
JP2023500692A JPWO2022176588A1 (ja) | 2021-02-17 | 2022-01-31 | |
US18/233,638 US20230384174A1 (en) | 2021-02-17 | 2023-08-14 | Load sensor |
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JP2021-023571 | 2021-02-17 | ||
JP2021023571 | 2021-02-17 |
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US18/233,638 Continuation US20230384174A1 (en) | 2021-02-17 | 2023-08-14 | Load sensor |
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WO2022176588A1 true WO2022176588A1 (ja) | 2022-08-25 |
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US (1) | US20230384174A1 (ja) |
JP (1) | JPWO2022176588A1 (ja) |
CN (1) | CN116917706A (ja) |
WO (1) | WO2022176588A1 (ja) |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005003531A (ja) * | 2003-06-12 | 2005-01-06 | Nitta Ind Corp | 静電容量型センサ |
US20130047747A1 (en) * | 2011-08-25 | 2013-02-28 | Samsung Electro-Mechanics Co., Ltd. | Capacitive pressure sensor and input device including the same |
JP2015187561A (ja) * | 2014-03-26 | 2015-10-29 | 株式会社日本自動車部品総合研究所 | 圧力センサ |
WO2018096901A1 (ja) * | 2016-11-25 | 2018-05-31 | パナソニックIpマネジメント株式会社 | 感圧素子および操舵装置 |
-
2022
- 2022-01-31 CN CN202280015411.0A patent/CN116917706A/zh active Pending
- 2022-01-31 WO PCT/JP2022/003600 patent/WO2022176588A1/ja active Application Filing
- 2022-01-31 JP JP2023500692A patent/JPWO2022176588A1/ja active Pending
-
2023
- 2023-08-14 US US18/233,638 patent/US20230384174A1/en active Pending
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005003531A (ja) * | 2003-06-12 | 2005-01-06 | Nitta Ind Corp | 静電容量型センサ |
US20130047747A1 (en) * | 2011-08-25 | 2013-02-28 | Samsung Electro-Mechanics Co., Ltd. | Capacitive pressure sensor and input device including the same |
JP2015187561A (ja) * | 2014-03-26 | 2015-10-29 | 株式会社日本自動車部品総合研究所 | 圧力センサ |
WO2018096901A1 (ja) * | 2016-11-25 | 2018-05-31 | パナソニックIpマネジメント株式会社 | 感圧素子および操舵装置 |
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JPWO2022176588A1 (ja) | 2022-08-25 |
CN116917706A (zh) | 2023-10-20 |
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