Pressure sensors and wearable sensors

Abstract

To provide a technology which can give off a sensor signal in which only the pressure to be truly detected is accurately reflected in a glove-type wearable sensor in which a film-like pressure sensor is assembled into a fingertip of a thin work glove.SOLUTION: A film-like pressure sensor is assembled into the fingertip of a glove-type wearable sensor and made by laminating in a vertical direction at least one or more flexible substrates and one sheet-like pressure-sensitive element one on top of another with the vertical direction, a pressure sensor longitudinal direction, and a pressure sensor lateral direction regarded as three coordinate axial directions in a three-dimensional orthogonal coordinate system, respectively. The film-like pressure sensor detects only the pressure applied to the fingertip of a wearer after the wearable sensor is worn.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a pressure sensor, and a glove-type wearable sensor in which the pressure sensor is incorporated at a fingertip portion.

Background Art

[0002] At the sites of the manufacturing industry today where automation of production lines is advancing, there are still no small number of work processes that require manual labor. These work processes requiring manual labor face challenges such as chronic labor shortage caused by the decline of the working-age population, as well as the retirement of skilled workers and the consequent shortage of successors. As part of efforts to solve these challenges, in recent years, the movements of skilled workers during work are converted into digital data, which is used as teaching materials in vocational training for successor development, or used as a reference for checking whether the work is accurate or not.

[0003] As a main method for converting the movements of a person during work into digital data, there is a method of having the worker wear various wearable sensors to directly sense the movements of the worker. As an example, when converting various manual operations including actions such as grasping and releasing an object into digital data, a method using a glove-type wearable sensor in which a film-shaped or sheet-shaped pressure sensor is incorporated at the fingertip of a work glove is known as an effective technique (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of Invention

Problems to be Solved by the Invention

[0005] In actual manufacturing environments, it is crucial that glove-type wearable sensors worn by workers have a comfortable fit that conforms well to the fingertips and does not hinder movement, so as not to interfere with work. Therefore, glove-type wearable sensors used for such applications are preferably those in which a film-like or sheet-like (hereinafter simply referred to as "film-like") pressure sensor is incorporated into the fingertips of a thin work glove.

[0006] However, when a wearable sensor is fabricated using thin work gloves to achieve a good fit, there is a problem in that various stresses act on the pressure-sensitive element inside the pressure sensor when the wearable sensor is attached or when the fingers are bent after attachment, causing the pressure sensor to react and acquiring unnecessary sensor values.

[0007] In view of the above problems, the present invention aims to provide a technology for a glove-type wearable sensor in which a film-like pressure sensor is incorporated into the fingertip of a thin work glove, which can emit a sensor signal that accurately reflects only the pressure that should truly be detected. [Means for solving the problem]

[0008] The pressure sensor according to the present invention is a film-like pressure sensor incorporated into the fingertip of a glove-type wearable sensor, in which at least one flexible substrate and one sheet-like pressure-sensitive element are stacked vertically, with the three coordinate axes in a three-dimensional Cartesian coordinate system being the vertical direction, the longitudinal direction of the pressure sensor, and the width direction of the pressure sensor, respectively, and it detects only the pressure applied to the wearer's fingertip after the wearer has attached the wearable sensor.

[0009] Furthermore, a glove-type wearable sensor in which the above-mentioned pressure sensor is incorporated into the fingertip is also within the scope of the present invention.

[0010] Furthermore, the problems disclosed in this application and their solutions will be made clear from the description in the section on embodiments for carrying out the invention and from the drawings. [Effects of the Invention]

[0011] According to the present invention, in a glove-type wearable sensor in which a film-like pressure sensor is incorporated into the fingertip of a thin work glove, it becomes possible to accurately detect only the pressure applied to the wearer's fingertip after the wearable sensor is attached. As a result, it becomes possible to emit a sensor signal that accurately reflects only the pressure that should truly be detected. [Brief explanation of the drawing]

[0012] [Figure 1] This shows the appearance of the wearable sensor. [Figure 2] The configuration of the pressure sensor according to Example 1 is shown. [Figure 3A] A modified example of the pressure sensor configuration according to Example 1 is shown below. [Figure 3B] A modified example of the pressure sensor configuration according to Example 1 is shown below. [Figure 4A] The configuration of the pressure sensor according to Example 2 is shown. [Figure 4B] The configuration of the pressure sensor according to Example 2 is shown. [Figure 5] A modified example of the configuration of the flexible substrate of the pressure sensor according to Example 2 is shown. [Figure 6] A modified example of the configuration of the flexible substrate of the pressure sensor according to Example 2 is shown. [Figure 7] The configuration of the pressure sensor according to Example 3 is shown. [Figure 8A] The configuration of the upper substrate of the pressure sensor according to Example 3 is shown. [Figure 8B] The configuration of the lower substrate of the pressure sensor according to Example 3 is shown. [Figure 9A] A modified example of the configuration of the upper substrate of the pressure sensor according to Example 3 is shown. [Figure 9B] A modified example of the configuration of the lower substrate of the pressure sensor according to Example 3 is shown. [Figure 10] Figure 9 shows the relationship between the electrode terminals used and the acquired sensor signal in a pressure sensor using a flexible substrate. MODE FOR CARRYING OUT THE INVENTION

[0013] Hereinafter, several embodiments will be described.

[0014] The following description is performed on the assumption that the three coordinate axis directions in a three-dimensional orthogonal coordinate system are the vertical direction, the longitudinal direction of the pressure sensor, and the width direction of the pressure sensor, respectively. EXAMPLES

[0015] First, an outline of the wearable sensor will be described.

[0016] Figure 1 shows the external appearance of the wearable sensor 1.

[0017] As shown in Figure 1, the wearable sensor 1 is a glove-type wearable sensor, also referred to as a sensor glove or a sensor-integrated glove, in which a film-shaped pressure sensor 11 is incorporated at the fingertip of a thin work glove. The pressure sensor 11 is incorporated in a region centered on the palmar side of the fingertip of the wearable sensor 1, and when the wearable sensor 1 is worn on the wearer's hand, the pressure sensor deforms to conform to the shape of the wearer's fingertip. As a result, the wearable sensor 1 fits well on the wearer's hand. Consequently, the wearer of the wearable sensor 1 can obtain a good wearing comfort that does not interfere with work even at an actual manufacturing site.

[0018] Further, in the wearable sensor 1, the pressure sensor 11 incorporated in the fingertip has features to be described later, whereby various stresses acting on the pressure-sensitive element of the pressure sensor 11 incorporated in the fingertip can be alleviated when the wearable sensor 1 is worn or when the finger is bent after wearing. As a result, the wearable sensor 1 can appropriately detect only the pressure applied to the wearer's fingertip after wearing (details will be described later).

[0019] In other words, the wearable sensor 1, by possessing the above-mentioned features, fits well to the wearer's fingertip and can accurately detect only the pressure applied to the wearer's fingertip after wearing.

[0020] Note that the wearable sensor 1 illustrated in Figure 1 is shown with the pressure sensor 11 integrated into the fingertip of the index finger for ease of understanding, but of course, the pressure sensor 11 may be integrated into the fingertips of other fingers, or into the fingertips of multiple fingers. Furthermore, the specific position and orientation of the pressure sensor 11 integrated into the fingertip of the wearable sensor 1 should be determined appropriately according to the type of movements the wearer performs during work and the wearer's physical characteristics.

[0021] Next, we will describe the pressure sensor incorporated into the wearable sensor 1.

[0022] Figure 2 shows the configuration of the pressure sensor 11a according to Example 1.

[0023] The pressure sensor 11a shown in Figure 2 includes one flexible substrate 12a, one pressure-sensitive element 13, and one protective film 14. The flexible substrate 12a has a sheet-like electrode made of conductive metal foil, such as copper foil, inside a polymer thick film (PTF). When viewed from above, the electrode on the flexible substrate 12a is roughly comb-shaped. A sheet-like pressure-sensitive element 13 is provided on the upper surface of the flexible substrate 12a, roughly parallel to the flexible substrate 12a. This pressure-sensitive element 13 is electrically connected to the electrode on the flexible substrate 12a. A protective film 14 made of insulating resin is placed on the upper surface of the pressure-sensitive element 13, and the upper surface of the flexible substrate 12a and the lower surface of the protective film 14 are bonded and fixed at the periphery of the pressure sensor 11a.

[0024] In other words, the pressure-sensitive element 13 is enclosed in the internal space of the pressure sensor 11a, which is formed by the upper surface of the flexible substrate 12a and the lower surface of the protective film 14, with its lower surface facing the upper surface of the flexible substrate 12a and its upper surface facing the lower surface of the protective film 14. A double-sided non-adhesive film 15 is interposed between the lower surface of the pressure-sensitive element 13 and the upper surface of the flexible substrate 12a, and between the upper surface of the pressure-sensitive element 13 and the lower surface of the protective film 14.

[0025] When various pressures are applied to the fingertip of the wearable sensor 1(1a) which incorporates the pressure sensor 11a, the pressure sensor 11a deforms, and the pressure-sensitive element 13 inside the pressure sensor 11a also deforms accordingly. Inside the pressure-sensitive element 13, when the wearable sensor 1(1a) is not attached, i.e., in the initial state, conductive microparticles are uniformly present at approximately equal intervals. However, when the pressure-sensitive element 13 deforms, the distance between the microparticles inside partially expands or contracts. As a result, the electrical resistance value inside the pressure-sensitive element 13 changes when power is applied. This allows the wearable sensor 1(1a) to detect various pressures applied to the fingertip.

[0026] Unlike the pressure sensor 11a, the conventional pressure sensor does not have a double-sided non-adhesive film 15 interposed between the lower surface of the pressure-sensitive element and the upper surface of the flexible substrate, nor between the upper surface of the pressure-sensitive element and the lower surface of the protective film. Instead, the lower surface of the pressure-sensitive element and the upper surface of the flexible substrate, and the upper surface of the pressure-sensitive element and the lower surface of the protective film are bonded together. Therefore, when the pressure sensor deforms, due to differences in the physical and mechanical properties of the flexible substrate, pressure-sensitive element, and protective film, in addition to (1) the stress acting on the pressure-sensitive element itself during deformation, (2) stress applied from the protective film and (3) stress applied from the flexible substrate act on the pressure-sensitive element. Consequently, the pressure detected by the conventional pressure sensor will be one of (1) to (3) above, or a combination of (1) to (3) above. Due to these problems, the conventional pressure sensor cannot accurately emit a sensor signal that reflects only the pressure that should truly be detected.

[0027] However, in the pressure sensor 11a, as described above, a double-sided non-adhesive film 15 is interposed between the lower surface of the pressure-sensitive element 13 and the upper surface of the flexible substrate 12a, and between the upper surface of the pressure-sensitive element 13 and the lower surface of the protective film 14. Therefore, the pressure-sensitive element 13 is positioned inside the pressure sensor 11a with its lower surface not adhered to the upper surface of the flexible substrate 12a, and its upper surface not adhered to the lower surface of the protective film 14. As a result, unnecessary stress that acted on the pressure-sensitive element in relation to the flexible substrate and protective film in the conventional technology is not applied to the pressure-sensitive element 13, so the pressure sensor 11a can emit a sensor signal that accurately reflects only the pressure that should truly be detected.

[0028] Furthermore, the pressure sensor may be protected by an adhesive film whose longitudinal side is divided into multiple sections, as shown in Figure 3. In this case, as shown in Figure 3A, the side of the pressure sensor 11b may be separately protected by an adhesive film 16 divided into multiple sections, or as shown in Figure 3B, the side of the protective film 14b protecting the side of the pressure sensor 11b may be divided into multiple sections. In this way, the stress on the side of the pressure sensor 11b can be alleviated by dividing the side of the adhesive film 16 or protective film 14b protecting the side of the pressure sensor 11b into multiple sections. [Examples]

[0029] The wearable sensor 1b of Example 2 is equivalent to the wearable sensor 1(1a) shown in Figure 1 in the description of Example 1, except that the structure of the pressure sensor incorporated in the fingertip is different.

[0030] Figure 4 shows the configuration of the pressure sensor 21 according to Example 2. Figure 4A is a vertical cross-sectional view, and Figure 4B is a top view.

[0031] The pressure sensor 21 shown in Figure 4 includes a flexible substrate 12a, a plurality of sheet-like pressure-sensitive elements 23 divided into strips with the width direction of the pressure sensor 21 as the longitudinal direction, and a protective film 14. The pressure-sensitive elements 23 are enclosed in the internal space of the pressure sensor 21, which is formed by the upper surface of the flexible substrate 12a and the lower surface of the protective film 14, with their lower surfaces facing the upper surface of the flexible substrate 12a and their upper surfaces facing the lower surface of the protective film 14. The pressure-sensitive elements 23 are arranged so as to be approximately parallel to each other, with a certain gap between each pressure-sensitive element 23. That is, the plurality of strip-shaped pressure-sensitive elements 23 are arranged at approximately equal intervals so that their respective width directions are in the longitudinal direction of the pressure sensor 21. As a result, the pressure sensor 21 bends at the positions of the gaps between the pressure-sensitive elements 23, so that the stress acting on each pressure-sensitive element 23 is only that which is truly caused by the pressure to be detected. As a result, the pressure sensor 21 can emit a sensor signal that accurately reflects only the pressure that should truly be detected.

[0032] Furthermore, the electrodes of the flexible substrate used in the pressure sensor 21 may have a wiring pattern formed such that the positions where each pressure-sensitive element 23 is placed overlap with the positions of the wires, as shown in Figure 5 of the flexible substrate 12b. In this case, the pressure sensor 21 can detect the stress acting on each pressure-sensitive element 23 with greater accuracy. Also, in this case, the pressure sensor 21 becomes more flexible at the gaps between the pressure-sensitive elements 23 because the wires of the flexible substrate 12b are not placed at the gaps between the pressure-sensitive elements 23. Moreover, in this case, when manufacturing the pressure sensor 21, it is possible to place each pressure-sensitive element 23 according to the wiring pattern of the flexible substrate 12b, making it easier to position each pressure-sensitive element 23.

[0033] Furthermore, the flexible substrate used in the pressure sensor 21 may be made more flexible, such as the flexible substrate 12c shown in Figure 6, where the position overlapping with the above-mentioned gap is made thinner than other positions, or where it is made of a more flexible material than other positions. In this case, the pressure sensor 21 can be made more flexible at the position of the gap provided between the pressure-sensitive elements 23. [Examples]

[0034] The wearable sensor 1c of Example 3 is equivalent to the wearable sensor 1(1a) shown in Figure 1 in the description of Example 1, except that the structure of the pressure sensor incorporated in the fingertip is different.

[0035] Figure 7 shows the configuration of the pressure sensor 31 according to Example 3.

[0036] The pressure sensor 31 shown in Figure 7 includes two different flexible substrates (32a, 32b) and a sheet-like pressure-sensitive element 33. The pressure-sensitive element 33 is equivalent to the pressure-sensitive element 13 of Embodiment 1 and is sealed in the internal space of the pressure sensor 31, which is formed by the upper surface of the upper flexible substrate 32a and the lower surface of the lower flexible substrate 32b, with its upper surface 51 facing the lower surface of the upper flexible substrate 32a and its lower surface 52 facing the upper surface of the lower flexible substrate 32b.

[0037] The upper surface 51 of the pressure-sensitive element 33 is bonded and fixed to the lower surface of the upper flexible substrate 32a. Therefore, tensile stress acts on the upper surface 51 of the pressure-sensitive element 33 in relation to the upper flexible substrate 32a.

[0038] Furthermore, the lower surface 52 of the pressure-sensitive element 33 is bonded and fixed to the upper surface of the lower flexible substrate 32b. Therefore, compressive stress acts on the lower surface 52 of the pressure-sensitive element 33 in relation to the lower flexible substrate 32b.

[0039] Unlike the flexible substrates (12a, 12b, 12c) of Examples 1 and 2, which are provided with both positive and negative electrodes 17, the upper flexible substrate 32a shown in Figure 8A and the lower flexible substrate 32b shown in Figure 8B are each provided with only one of either positive or negative electrodes. The upper flexible substrate 32a shown in Figure 8A is provided with the positive electrode, and the lower flexible substrate 32b shown in Figure 8B is provided with the negative electrode. Therefore, in the pressure sensor 31, current flows from the lower flexible substrate 32b through the pressure-sensitive element 33 to the upper flexible substrate 32a. As a result, the tensile stress acting on the upper surface 51 of the pressure-sensitive element 33 in relation to the upper flexible substrate 32a and the compressive stress acting on the lower surface 52 of the pressure-sensitive element 33 in relation to the lower flexible substrate 32b cancel each other out, so that the pressure sensor 31 can eliminate the influence of these stresses. As a result, the pressure sensor 31 can emit a sensor signal that accurately reflects only the pressure that should truly be detected.

[0040] As shown in Figures 8A and 8B, the orientation of the stripes on the electrodes of the upper flexible substrate 32a and the lower flexible substrate 32b, which are arranged in a roughly striped pattern, may be set to different directions. By making the electrodes of the flexible substrates (32a, 32b) roughly striped, the pressure sensor 31 can be easily bent in the direction of the stripes. In addition, if the orientation of the stripes on the electrodes of the upper flexible substrate 32a and the lower flexible substrate 32b are set to different directions, the change in resistance value when pressure is applied to each location of the pressure sensor 31 can be made uniform.

[0041] Furthermore, the flexible substrates used in the pressure sensor 31 may have different numbers of electrodes, as shown in Figure 9A (flexible substrate 42a) and Figure 9B (flexible substrate 42b). The upper flexible substrate 42a shown in Figure 9A has two electrodes formed in a roughly comb-like shape. The lower flexible substrate 42b shown in Figure 9B has one electrode formed in a roughly striped shape. In this case, the pressure sensor 31 can appropriately separate the pressure applied to the finger from other miscellaneous pressures by devising the wiring, as shown in Figure 10. As a result, the pressure sensor 31 can eliminate the influence of unwanted pressures that were detected in conventional pressure sensors when the wearer of the wearable sensor 1c performs a finger bending motion.

[0042] It should be noted that the present invention is not limited to the embodiments described above, and can be implemented using any components without departing from the spirit of the invention.

[0043] The embodiments and modifications described above are merely examples, and the present invention is not limited to these, as long as the features of the invention are not impaired. Furthermore, although various embodiments and modifications have been described above, the present invention is not limited to these. Other embodiments conceivable within the scope of the technical idea of ​​the present invention are also included within the scope of the present invention. [Explanation of Symbols]

[0044] 1: Wearable Sensors 11,11a,11b,21,31: Pressure sensors 12, 12a, 12b, 12c: Flexible substrate 13, 23, 33: Pressure-sensitive material 14,14b: Protective film 15: Double-sided non-adhesive film 16: Protective film 17,37a,37b,47a,47b: Electrodes (wiring patterns) 18: Areas that are prone to bending 32a, 42a: Flexible substrate (upper side) 32b, 42b: Flexible circuit board (lower side) 51: Surface under tensile stress 52: Surface under compressive stress

Claims

1. A glove-type wearable sensor, Gloves and Film-type pressure sensor and Equipped with, The pressure sensor is incorporated into the fingertip of the glove. The three coordinate axis directions in the three-dimensional Cartesian coordinate system include the vertical direction of the sensor layer of the pressure sensor, the longitudinal direction of the pressure sensor, and the width direction of the pressure sensor in the same plane as the longitudinal direction. The wearable sensor detects only the pressure applied to the wearer's fingertips after the sensor is attached. The pressure sensor includes a flexible substrate, a sheet-shaped pressure-sensitive element, and a protective film, which are stacked in the vertical direction. A first double-sided non-adhesive film is interposed between the upper surface of the flexible substrate and the lower surface of the pressure-sensitive element, and a second double-sided non-adhesive film is interposed between the upper surface of the pressure-sensitive element and the lower surface of the protective film. A glove-shaped wearable sensor.

2. A glove-type wearable sensor according to claim 1, wherein the longitudinal side surface of the pressure sensor is protected by a portion of the protective film which is divided into multiple parts.

3. A glove-type wearable sensor, Gloves and Film-type pressure sensor and Equipped with, The pressure sensor is incorporated into the fingertip of the glove. The three coordinate axis directions in the three-dimensional Cartesian coordinate system include the vertical direction of the sensor layer of the pressure sensor, the longitudinal direction of the pressure sensor, and the width direction of the pressure sensor in the same plane as the longitudinal direction. The wearable sensor detects only the pressure applied to the wearer's fingertips after the sensor is attached. The pressure sensor includes a flexible substrate, a pressure-sensitive element, and a protective film, which are stacked in the vertical direction. The pressure-sensitive elements are arranged at approximately equal intervals within the internal space of the pressure sensor, which is formed by the upper surface of the flexible substrate and the lower surface of the protective film, such that their respective width directions are aligned with the longitudinal direction of the pressure sensor. The flexible substrate is formed to be easily bent in the area that overlaps with the gap provided between the pressure-sensitive elements. A glove-shaped wearable sensor.

4. A glove-type wearable sensor according to claim 3, The flexible substrate has a wiring pattern formed such that the positions where each of the pressure-sensitive elements is placed overlap with the positions of the wires. A glove-shaped wearable sensor.

5. A glove-type wearable sensor according to claim 1 or 3, The pressure-sensitive element is sandwiched between two of the flexible substrates. Each of the two flexible substrates is provided with either a positive or negative electrode, A glove-shaped wearable sensor.

6. A glove-type wearable sensor according to claim 5, Each of the two flexible substrates is provided with electrodes formed in a roughly striped pattern. The orientation of the electrode stripes on the upper flexible substrate and the orientation of the electrode stripes on the lower flexible substrate are in different directions. A glove-shaped wearable sensor.

7. A glove-type wearable sensor according to claim 5, The upper flexible substrate is provided with two or more electrodes formed in a roughly comb-like shape. The lower flexible substrate is provided with a single electrode formed in a roughly striped pattern. A glove-shaped wearable sensor.

8. A glove-type wearable sensor according to claim 1, The side surface of the pressure sensor is protected by an adhesive film that is divided into multiple parts in the longitudinal direction. A glove-shaped wearable sensor.

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