Displacement sensor and displacement measurement system using the displacement sensor

Abstract

A displacement sensor comprising: a first light-emitting particle layer which is provided so as to be capable of making contact with an object to be measured, and in which first light-emitting particles that emit light at a first wavelength in response to excitation energy are distributed across at least a one-dimensional span; a second light-emitting particle layer in which second light-emitting particles that emit light at a second wavelength different from the first wavelength in response to the excitation energy are distributed across the span; and a spacer layer by which the first light-emitting particle layer and the second light-emitting particle layer are separated from each other along a direction orthogonal to the span, and which includes an excitation energy absorbing material for absorbing the excitation energy.

Description

[Technical Field]

[0001] The present disclosure relates to a displacement sensor and a surface shape measuring device using the displacement sensor, and in particular to a displacement measurement system using a displacement sensor that measures minute displacements or minute pressures. [Background technology]

[0002] Conventionally, a known system for measuring displacement or pressure is one that combines a pressure-sensitive resin with a large number of thin-film transistors. Pressure-sensitive resin is made by dispersing conductive particles in an insulating resin such as silicone rubber. When pressure is applied to the pressure-sensitive resin, the conductive particles come into contact with each other within the insulating resin, causing a decrease in resistance. This makes it possible to detect the pressure applied to the pressure-sensitive resin. The large number of thin-film transistors are arranged in a matrix and function as electrodes.

[0003] There is also known a pressure sensor in which a pressure-sensitive layer and multiple electrodes are arranged facing each other with a predetermined gap between them (see, for example, Patent Document 1). For example, the technology described in Patent Document 1 has a wide pressure measurement range and can measure a large area by arranging individual electrodes with different gaps between the pressure-sensitive layer and the electrodes in a matrix. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6322247 Summary of the Invention

[0005] A displacement sensor according to one embodiment of the present disclosure is configured by stacking a first light-emitting particle layer that is provided so as to be in contact with an object to be measured, in which first light-emitting particles that emit light at a first wavelength in response to excitation energy are distributed over at least one-dimensional extent; a second light-emitting particle layer that has second light-emitting particles that emit light at a second wavelength different from the first wavelength in response to excitation energy distributed over the extent; and a spacer layer that separates the first light-emitting particle layer and the second light-emitting particle layer in a direction intersecting the extent and that includes an excitation energy absorbing material that absorbs the excitation energy.

[0006] A displacement sensor according to another aspect of the present disclosure is provided in contact with an object to be measured, and includes: a first light-emitting particle layer in which first light-emitting particles that emit light at a first wavelength in response to excitation energy are distributed over at least one-dimensional extent; a second light-emitting particle layer in which second light-emitting particles that emit light at a second wavelength different from the first wavelength in response to excitation energy are distributed over the extent; a first spacer layer that separates the first light-emitting particle layer and the second light-emitting particle layer in a direction intersecting the extent and includes an excitation energy absorber that absorbs the excitation energy; and a third light-emitting particle layer in which third light-emitting particles that emit light at a third wavelength different from the first and second wavelengths in response to excitation energy are distributed over the extent. the fourth light-emitting particle layer in which fourth light-emitting particles that emit light at a fourth wavelength different from the first, second, and third wavelengths due to excitation energy are distributed over the extent; a second spacer layer that separates the third light-emitting particle layer from the fourth light-emitting particle layer in a direction intersecting the extent; and an energy transfer prevention layer that separates the second light-emitting particle layer from the third light-emitting particle layer in a direction intersecting the extent, and is configured by laminating the first light-emitting particle layer, the first spacer layer, the second light-emitting particle layer, the energy transfer prevention layer, the third light-emitting particle layer, the second spacer layer, and the fourth light-emitting particle layer in this order. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic diagram showing the configuration of a displacement sensor according to a first embodiment and a displacement measurement system using the same. [Figure 2]2 is a schematic cross-sectional view showing a state in which the displacement sensor of FIG. 1 is brought into contact with the surface of an object to be measured along the surface by a pressure member. FIG. [Figure 3] 10 is a graph showing an emission spectrum from a recess of an object to be measured. [Figure 4] 10 is a graph showing an emission spectrum from a convex portion of an object to be measured. [Figure 5] FIG. 10 is a schematic diagram showing the configuration of a displacement sensor according to a second embodiment and a displacement measurement system using the same. [Figure 6] 10 is a graph showing an emission spectrum from a recess of an object to be measured. [Figure 7] 10 is a graph showing an emission spectrum from a convex portion of an object to be measured. DETAILED DESCRIPTION OF THE INVENTION

[0008] In conventional configurations, arranging individual electrodes with different gaps requires a constant pressing area, making it difficult to measure minute areas. In addition, because individual electrodes are arranged in an array, there is the problem that the circuit becomes complicated when measuring samples with a large measurement area.

[0009] Furthermore, when measuring minute surface irregularities or pressure, the additional provision of an optical film causes the measurement to be affected by the physical properties of the optical film, resulting in a problem of reduced accuracy.

[0010] The present disclosure aims to solve the above-mentioned conventional problems, and to provide a displacement sensor that can improve measurement accuracy and simplify displacement measurement in a microscopic area, as well as a displacement measurement system that uses the displacement sensor.

[0011] A displacement sensor according to a first aspect is provided so as to be in contact with an object to be measured, and includes: a first light-emitting particle layer in which first light-emitting particles that emit light at a first wavelength in response to excitation energy are distributed across at least one-dimensional extent; a second light-emitting particle layer in which second light-emitting particles that emit light at a second wavelength different from the first wavelength in response to the excitation energy are distributed across the extent; and a spacer layer that separates the first light-emitting particle layer and the second light-emitting particle layer in a direction intersecting the extent and includes an excitation energy absorption material that absorbs the excitation energy.

[0012] In the displacement sensor according to the second aspect, in the above-mentioned first aspect, the first luminescent particles and the second luminescent particles may have an overlap between the emission spectrum of one type of luminescent particle and the absorption spectrum of the other type of luminescent particle.

[0013] A displacement sensor according to a third aspect is the same as that of the first or second aspect, and may use at least one of semiconductor nanoparticles and organic dyes as the first and second phosphor particles.

[0014] In a displacement sensor according to a fourth aspect, in any one of the first to third aspects, the second light-emitting particles that are separated from the first light-emitting particles on the contact surface with the object to be measured by a spacer layer may have a shorter emission peak wavelength.

[0015] A displacement sensor according to a fifth aspect is provided so as to be in contact with an object to be measured, and includes: a first light-emitting particle layer in which first light-emitting particles that emit light at a first wavelength in response to excitation energy are distributed over at least one-dimensional extent; a second light-emitting particle layer in which second light-emitting particles that emit light at a second wavelength different from the first wavelength in response to the excitation energy are distributed over the extent; a first spacer layer that separates the first light-emitting particle layer and the second light-emitting particle layer in a direction intersecting the extent and includes an excitation energy absorber that absorbs the excitation energy; and a third light-emitting particle layer that emits light at a third wavelength different from the first and second wavelengths in response to the excitation energy and is distributed over the extent. the fourth light-emitting particle layer in which fourth light-emitting particles that emit light at a fourth wavelength different from the first, second, and third wavelengths due to the excitation energy are distributed across the spread; a second spacer layer that separates the third light-emitting particle layer from the fourth light-emitting particle layer in a direction intersecting the spread; and an energy transfer prevention layer that separates the second light-emitting particle layer from the third light-emitting particle layer in a direction intersecting the spread, and is configured by laminating the first light-emitting particle layer, the first spacer layer, the second light-emitting particle layer, the energy transfer prevention layer, the third light-emitting particle layer, the second spacer layer, and the fourth light-emitting particle layer in this order.

[0016] A displacement sensor according to a sixth aspect is the fifth aspect, wherein the first and second luminescent particles have an overlap between the emission spectrum of one type of luminescent particle and the absorption spectrum of the other type of luminescent particle.

[0017] A displacement sensor according to a seventh aspect is the fifth or sixth aspect, wherein the first and second phosphor particles may be at least one of semiconductor nanoparticles and organic dyes.

[0018] The displacement sensor according to the eighth aspect is any one of the fifth to seventh aspects, wherein the second luminescent particles, which are separated from the first luminescent particles on the contact surface with the object to be measured by sandwiching the first spacer layer therebetween, may have a short emission peak wavelength.

[0019] A displacement measuring system according to a ninth aspect uses the displacement sensor according to any one of the first to eighth aspects.

[0020] A pressure measurement system according to a tenth aspect uses the displacement sensor according to any one of the first to eighth aspects.

[0021] A displacement measurement system according to an eleventh aspect includes a displacement sensor according to any one of the first to eighth aspects, an excitation energy source that causes two or more types of first and second luminescent particles contained in the displacement sensor to emit light, and a light receiving unit that receives the light emitted from the displacement sensor.

[0022] As described above, the displacement sensor according to one aspect of the present disclosure and the displacement measurement system using the displacement sensor can measure displacement or pressure in a minute area with high accuracy.

[0023] A displacement sensor and a displacement measurement system using the same according to an embodiment will be described below with reference to the accompanying drawings. In the drawings, substantially identical components are designated by the same reference numerals.

[0024] (Embodiment 1) 1 is a schematic diagram showing the configuration of a displacement sensor 200 according to embodiment 1 and a displacement measurement system 10 using the same. For convenience, in the drawing, the plane showing the extent of the displacement sensor 200 is shown as an XY plane, the right side of the paper is shown as the X direction, and the vertically upward is shown as the Z direction.

[0025] <Displacement sensor> 1, the displacement sensor 200 is provided so as to be able to come into contact with the object to be measured 001, and includes a first light-emitting particle layer 21, a spacer layer 212a, and a second light-emitting particle layer 22. In the first light-emitting particle layer 21, first light-emitting particles 211 that emit light at a first wavelength in response to excitation energy are distributed across at least a one-dimensional spread (XY plane). In the second light-emitting particle layer 22, second light-emitting particles 213 that emit light at a second wavelength different from the first wavelength in response to excitation energy are distributed across the spread. The spacer layer 212a separates the first light-emitting particle layer 21 and the second light-emitting particle layer 22 in a direction (Z direction) intersecting the spread. The spacer layer 212a includes an excitation energy absorber 212b that absorbs excitation energy. The excitation energy causes the second luminescent particles 213 to emit light (16a: FIGS. 3 and 4), and the first luminescent particles 211 emit light (16b: FIGS. 3 and 4) depending on the distance between the first luminescent particles 211 and the second luminescent particles 213. The emission wavelength distribution makes it possible to detect changes in the distance (Z direction) between the two types of first luminescent particle layers 21 and second luminescent particle layers 22, and to measure displacement or pressure in a microscopic area with high precision. The displacement sensor 200 may be supported by a support 220.

[0026] Each of the components that make up this displacement sensor 200 will be described below.

[0027] The displacement sensor 200 is provided so as to be able to come into contact with the object to be measured 001. The displacement sensor 200 has a layer structure in which a first light-emitting particle layer 21 and a second light-emitting particle layer 22 are arranged opposite each other with a spacer layer 212a interposed therebetween. The spacer layer 212a includes an excitation energy absorbing material 212b that absorbs excitation energy, and the first light-emitting particle layer 21 is provided on the contact surface side with the object to be measured 001.

[0028] <Luminescent particles> The first light-emitting particle layer 21 and the second light-emitting particle layer 22 respectively contain two types of first light-emitting particles 211 and second light-emitting particles 213 which emit light 14 in response to excitation energy at different wavelengths. In the first light-emitting particle layer 21 and the second light-emitting particle layer 22, the first light-emitting particles 211 and the second light-emitting particles 213 are distributed over at least a one-dimensional extent. Specifically, in the case of Fig. 1, the first light-emitting particles 211 and the second light-emitting particles 213 are distributed over the XY plane, i.e., over a two-dimensional extent. However, the present invention is not limited to this, and the first light-emitting particles 211 and the second light-emitting particles 213 may be distributed only in the X direction, i.e., over a one-dimensional extent.

[0029] The emission wavelengths of the first and second light-emitting particles 211 and 213 are selected by selecting a combination of materials such that the second light-emitting particles 213 emit light at a shorter wavelength than the first light-emitting particles 211 (FIGS. 2 and 3). The first and second light-emitting particles 211 and 213 may be semiconductor nanoparticles having a core of cadmium sulfide, cadmium selenide, cadmium telluride, zinc sulfide, zinc selenide, zinc telluride, copper indium sulfide, silver indium sulfide, indium phosphide, or mixed crystal materials thereof; perovskite-type semiconductor nanoparticles such as cesium lead halide; semiconductor nanoparticles having a core of silicon, carbon, or the like; or organic dyes such as merocyanine and perylene.

[0030] The particle size of the two or more types of first and second light-emitting particles 211, 213 of semiconductor nanoparticles may be any particle size that can obtain the quantum size effect, and is preferably 1 nm to 100 nm, more preferably 1 nm to 50 nm. The particle size of the organic dye powder is not an influence even if the raw material is in powder form.

[0031] <Support> The support 220 is not particularly limited as long as it is a material that is easy to handle and does not inhibit the light emission 14 from the first light-emitting particles 211 and the second light-emitting particles 213. For example, polyethylene terephthalate, polyacrylamide, polycarbonate, etc. can be used. However, if there is no problem with handling of the displacement sensor 200, the support 220 is not necessarily a necessary component.

[0032] <Spacer layer> The spacer layer 212a is not particularly limited as long as it is a material that can be compressed by pressure and does not inhibit the light emission 14 from the first and second phosphor particles 211, 213, but is partially limited by the manufacturing method described below.

[0033] The thickness of the spacer layer 212a is preferably 1 nm or more and 1000 nm or less. More preferably, it is 1 nm or more and 500 nm or less, and even more preferably, it is 3 nm or more and 300 nm or less. If it is 1 nm or more, it is possible to ensure the change in the distance between the first light-emitting particles 211 and the second light-emitting particles 213 necessary for detection. If it is 1000 nm or less, it becomes easier for the change in the distance between the first and second light-emitting particles 211, 213 to occur due to the displacement of the contacting object to be measured 001, thereby improving the accuracy of the sensor.

[0034] The method for manufacturing the spacer layer 212a is not particularly limited, but may be a method capable of controlling a thin film, such as a layer-by-layer (LBL) method or a spin coater method.

[0035] The LBL method is a technique that allows for the alternate adsorption of cationic polymers and anionic polymers by electrostatic force, thereby controlling the formation of thin films.

[0036] The material of the spacer layer 212a is not particularly limited, but is partially limited by the construction method used. For example, in the LBL method, ionic polymers such as cationic polymers such as polyallylamine and polydiallyldimethylammonium chloride, anionic polymers such as polyacrylic acid, polystyrene sulfonic acid, and polyisoprene sulfonic acid, or copolymers containing these can be used. In addition, in the spin coater method, any material that dissolves in a solvent can be used, including the ionic polymers mentioned above, silicone resin, polyvinyl chloride, polyurethane, polyvinyl alcohol, polypropylene, polyacrylamide, polycarbonate, and polyethylene terephthalate. By controlling the thickness of the spacer layer 212a, the distance between the two types of light-emitting particles in the plane can be freely controlled.

[0037] <Excitation energy absorber> The excitation energy absorber 212b is not particularly limited as long as it is a material that absorbs excitation energy. When the excitation energy is excitation light 13 and the excitation light 13 is ultraviolet light of 400 nm or less, examples of ultraviolet absorbers include benzotriazole-based materials, benzophenone-based materials, and triazine-based materials. When the excitation light 13 is visible light of 400 nm to 500 nm, examples of ultraviolet absorbers include merocyanine-based materials and azo-based materials.

[0038] These materials may be added during the production of the spacer layer 212a, or polymers obtained by adding these materials to polymer materials may be used.

[0039] The content of the excitation energy absorber 212b is preferably 1% or more and 25% or less of the thickness t of the spacer layer 212a. More preferably, it is 5% or more and 20% or less. If it is 1% or more, the absorption intensity is high and accuracy is improved. Also, if it is 25% or less, the thickness of the spacer layer 212a is easily changed and the accuracy of the sensor is improved.

[0040] By providing the excitation energy absorbing material 212b, the DUT 001 can be protected from excitation energy, for example, ultraviolet light.

[0041] The excitation energy absorbing material 212b may be distributed over the entire spacer layer 212a, or may be unevenly distributed as an excitation energy absorbing layer in a part of the spacer layer 212a.

[0042] <Displacement measurement system> As shown in Fig. 1, the displacement measurement system 10 according to the first embodiment uses the displacement sensor 200. The displacement measurement system 10 includes an excitation energy source 100, a displacement sensor 200, a light-emitting / light-receiving element 300, and an image analysis unit 400. The displacement sensor 200 has been described above, and a description thereof will be omitted. Excitation light 13 from the excitation energy source 100 causes two or more types of first and second light-emitting particles 211, 213 contained in the displacement sensor 200 to emit light. Light emission 14 from the displacement sensor 200 is received by the light-emitting / light-receiving element 300.

[0043] This displacement measurement system 10 has a displacement sensor 200 in which two or more types of first and second light-emitting particles 211, 213 that emit light at different wavelengths are distributed over at least one dimension. Therefore, the change in distance (Z direction) between the two or more types of first and second light-emitting particle layers 21, 22 can be detected based on the wavelength distribution of the emitted light, and displacement or pressure in a microscopic area can be measured.

[0044] Each component constituting the displacement measuring system 10 will be described below.

[0045] <Excitation energy source> The excitation energy source 100 is not particularly limited as long as it is an excitation energy source that can excite the first and second light-emitting particles 211, 213 included in the displacement sensor 200. For example, an optical energy source (FIG. 1) or an electric energy source can be used. Note that the source is not limited to the optical energy source shown in FIG. 1. Furthermore, in order to evaluate the entire observation range at once, the excitation energy source 100 may uniformly supply excitation energy to the first and second light-emitting particles 211, 213.

[0046] <Light emitting and receiving element> The light emitting and receiving element 300 is not particularly limited as long as it is a light receiving element that can receive changes in the light emitting behavior of the first and second light emitting particles 211, 213. In particular, it is possible to use, for example, a CCD, a CMOS, an image sensor, or the like that can evaluate the entire observation range at once. By using these, it is possible to instantly analyze the light emitting behavior within the observation range.

[0047] When a light energy source is used as the excitation energy source, it is preferable to use a wavelength cut filter to suppress the influence of the wavelength of the excitation energy source 100 in order to increase the detection sensitivity in the light emitting / receiving element 300 .

[0048] <Image analysis section> The sensor may further include an image analysis unit 400 that measures the displacement of the object 001 in contact with the displacement sensor 200 based on the wavelength distribution of the received light emission. The image analysis unit 400 preferably analyzes the obtained image in terms of chromaticity and luminance, and calculates coordinates that provide the chromaticity and luminance differences from the surroundings. The image analysis unit 400 measures the displacement of the object 001 in contact with the displacement sensor 200 based on the wavelength distribution of the received light emission 14. Specifically, the wavelength distribution of the obtained light emission 14 can detect changes in the distance between the two types of first and second light-emitting particles 211, 213, and measure displacement or pressure in a microscopic area. The principle of displacement measurement will be described in detail later.

[0049] In this displacement measurement system 10, the excitation energy source 100 and the light emitting / receiving element 300 are arranged obliquely with respect to the plane of the displacement sensor 200, but this arrangement is an example and is not particularly limited thereto.

[0050] <Principles of displacement measurement> Next, the principle of displacement measurement in the displacement measurement system 10 according to the first embodiment will be described.

[0051] Consider two or more types of luminescent particles with different emission wavelengths, where the fluorescence spectrum (emission spectrum) of one luminescent particle (donor) overlaps with the excitation spectrum (absorption spectrum) of the other luminescent particle (acceptor). In this case, when two luminescent particles with different emission wavelengths are close to each other, it is known that the excitation energy excites the acceptor before the donor emits light. This behavior is called Förster resonance energy transfer (FRET), and the wavelength distribution of the emission spectra of the two luminescent particles depends on the distance between them. In particular, if the FRET efficiency is defined as the ratio of the number of energy transfers per number of donor excitations, the FRET efficiency is inversely proportional to the sixth power of the distance between the two luminescent particles. Therefore, even a slight change in distance can significantly affect the emission spectrum.

[0052] In the displacement measurement system 10 using this displacement sensor 200, the displacement sensor 200 is placed on the object to be measured 001 and a constant load is applied. When the object to be measured 001 has minute irregularities, the load on the displacement sensor 200 differs only at the irregularities compared to other locations. As a result, the amount of compression at the corresponding location of the displacement sensor 200 differs from that at other locations for the irregularities on the object to be measured 001. In other words, the distance between the two types of light-emitting particle layers changes only at the irregularities. The emission spectrum changes due to the FRET effect in response to the change in the distance between the two types of light-emitting particle layers. Therefore, by measuring the emission spectra of the two types of light-emitting particles, the change in the emission spectrum occurring at the irregularities within the surface can be converted into the change in the distance between the two types of light-emitting particle layers, i.e., the displacement of the object to be measured 001. Furthermore, before measuring the object to be measured 001, it is also possible to measure a reference mold and determine the relationship between the minute irregularities and the displacement from the difference between the measurement using the object to be measured 001 and the measurement using the reference mold.

[0053] In order to calculate the amount of displacement, the change in the emission spectrum may be measured in advance using known materials with different displacements.

[0054] Here, the change in emission spectrum will be specifically described. For example, a case where semiconductor nanoparticles are used as the luminescent particles will be described. Semiconductor nanoparticles are nano-sized particles having semiconductor crystals, and have the property that the emission spectrum changes depending on the particle diameter due to the quantum size effect. Furthermore, even if the particle diameter is the same, the emission spectrum changes depending on the material, and it is possible to realize a variety of emission spectra.

[0055] In addition, when luminescent particles have the same particle diameter but are made of different materials, the material with a larger energy gap will emit light at a shorter wavelength.

[0056] Fig. 2 is a schematic cross-sectional view showing a state in which the displacement sensor 200 of Fig. 1 is brought into contact with the surface of the object to be measured 001 by the pressure member 20. Fig. 3 is a graph showing an emission spectrum from the recess 11 of the object to be measured 001. Fig. 4 is a graph showing an emission spectrum from the protrusion 12 of the object to be measured 001.

[0057] The semiconductor nanoparticles having a shorter emission wavelength are referred to as semiconductor nanoparticles (second luminescent particles) 213, and the semiconductor nanoparticles having a longer emission wavelength are referred to as semiconductor nanoparticles (first luminescent particles) 211. In the recess 11 of the object to be measured 001 in FIG. 2, the distance between the two first luminescent particles 211 and the second luminescent particles 213 is sufficiently large. In this state, as shown in FIG. 3, almost no transfer of excitation energy occurs from the second luminescent particles 213 to the first luminescent particles, and therefore the emission 16b of the first luminescent particles 211 is slight. For this reason, the excitation energy is absorbed by the excitation energy absorber 212b, and only the emission spectra 15a and 16a of the second luminescent particles 213 are obtained (FIG. 3). On the other hand, in the convex portion 12 of the object to be measured 001 in FIG. 2, the distance between the first luminescent particles 211 and the second luminescent particles 213 is short. In this state, as shown in Fig. 4, the second luminescent particles 213 are excited depending on the distance between the first luminescent particles 211 and the second luminescent particles 213, and energy transfer (FRET) occurs from the second luminescent particles 213 to the first luminescent particles 211 before the second luminescent particles 213 emit light, and the energy that would have been emitted from the second luminescent particles 213 is used for the emission of light by the first luminescent particles 211. As a result, as shown in Fig. 4, the luminescence spectrum intensity 16a of the second luminescent particles 213 decreases, and the luminescence spectrum 16b of the first luminescent particles 211 appears (Fig. 4). That is, in the overall luminescence spectrum 15b of the two first and second luminescent particles 211, 213, the luminescence spectrum intensity 16a of the second luminescent particles 213 on the short wavelength side is reduced compared to the case of a single particle, and the luminescence spectrum intensity 16b of the first luminescent particle 211 on the long wavelength side has a wavelength distribution in which the luminescence spectrum intensity 16a is reduced compared to the case of a single particle, and the luminescence spectrum intensity 16b of the first luminescent particle 211 on the long wavelength side newly appears. The behavior of the wavelength distribution in the overall emission spectra 15a, 15b changes depending on the distance between the two second and first light-emitting particles 213, 211.

[0058] At this time, the type of excitation energy absorber is changed depending on the absorption wavelength of the second light-emitting particle on the short wavelength side, whether it is in the ultraviolet range of 400 nm or less or in the visible range of 400 nm to 500 nm. In either case, the principle is the same as described above.

[0059] Therefore, based on the wavelength distribution of the emission spectrum within the plane of the displacement sensor, the change in the distance between the two types of semiconductor nanoparticles 213 and 211, that is, the displacement of the object to be measured, can be calculated.

[0060] It is also possible to calculate the pressure exerted by the object to be measured instead of the displacement of the object to be measured based on the wavelength distribution of the emission spectrum within the surface of the displacement sensor.

[0061] As described above, when the FRET phenomenon occurs, the emission spectrum 16a of the second light-emitting particles emitting light on the short wavelength side decreases, and the emission spectrum 16b of the first light-emitting particles emitting light on the long wavelength side increases. The emission peak wavelength of the second light-emitting particles 213 on the short wavelength side and the emission peak wavelength of the first light-emitting particles 211 on the long wavelength side are preferably 10 nm or more apart, more preferably 30 nm or more apart. If the emission peak wavelengths are closer than 10 nm, the emission peak intensity of the spectrum with the lower emission intensity overlaps with the other spectrum, making it difficult to detect changes in the wavelength distribution in the emission spectra.

[0062] (Embodiment 2) 5 is a schematic diagram showing the configuration of a displacement sensor 201 according to embodiment 2 and a displacement measurement system 10a using the same. For convenience, in the drawing, the plane showing the extent of the displacement sensor 201 is shown as an XY plane, the right side of the paper is shown as the X direction, and the vertically upward is shown as the Z direction.

[0063] 5, a displacement sensor 201 is provided so as to be able to come into contact with an object to be measured 001, and is configured by sequentially laminating a first light-emitting particle layer 21, a first spacer layer 212a, a second light-emitting particle layer 22, an energy transfer prevention layer 214, a third light-emitting particle layer 23, a second spacer layer 212c, and a fourth light-emitting particle layer 24. In the first light-emitting particle layer 21, first light-emitting particles 211 that emit light at a first wavelength in response to excitation energy are distributed across at least a one-dimensional spread (XY plane). In the second light-emitting particle layer 22, second light-emitting particles 213 that emit light at a second wavelength different from the first wavelength in response to excitation energy are distributed across the spread. In the third light-emitting particle layer 23, third light-emitting particles 215 that emit light at a third wavelength different from the first and second wavelengths in response to excitation energy are distributed across the spread. The fourth light-emitting particle layer 24 has fourth light-emitting particles 216 that emit light at a fourth wavelength different from the first, second, and third wavelengths in response to excitation energy distributed across the above-mentioned extent. A first spacer layer 212a separates the first light-emitting particle layer 21 from the second light-emitting particle layer 22 in a direction (Z direction) intersecting the above-mentioned extent. The first spacer layer 212a includes an excitation energy absorber 212b that absorbs excitation energy. An energy transfer prevention layer 214 separates the second light-emitting particle layer 22 from the third light-emitting particle layer 23 in a direction (Z direction) intersecting the above-mentioned extent. A second spacer layer 212c separates the third light-emitting particle layer 23 from the fourth light-emitting particle layer 24 in a direction intersecting the above-mentioned extent. The excitation energy causes the second light-emitting particles 213, the third light-emitting particles 215, and the fourth light-emitting particles 216 to emit light, and the first light-emitting particles 211 emit light according to the distance between the first light-emitting particles 211 and the second light-emitting particles 213. The emission wavelength distribution makes it possible to detect the distance between the first and second light-emitting particles 211, 213 and the distance between the third and fourth light-emitting particles 215, 216, and thus makes it possible to measure the displacement or pressure of a microscopic area with higher precision.

[0064] The displacement sensor 201 may be supported by a support 220 .

[0065] The displacement sensor 201 according to the second embodiment is composed of a first light-emitting particle layer 21, a first spacer layer 212a, a second light-emitting particle layer 22, an energy transfer prevention layer 214, a third light-emitting particle layer 23, a second spacer layer 212c, and a fourth light-emitting particle layer 24. The layer that comes into contact with the object to be measured 001 is the first light-emitting particle layer 21, and only the first spacer layer 212a contains an excitation energy absorbing material 212b.

[0066] The first to fourth phosphor particles 211, 213, 215, 216, the first and second spacer layers 212a, 212c, and the excitation energy absorber 212b are the same components as those in the first embodiment, and therefore descriptions thereof will be omitted.

[0067] <Energy transfer prevention layer> To utilize the above-mentioned FRET effect, the distance between the first and second light-emitting particles and the distance between the third and fourth light-emitting particles may be detected. In this case, two types of light-emitting particles may be grouped into pairs, and a total of four light-emitting particle layers may be stacked to form a displacement sensor. Therefore, in order to suppress excitation energy transfer between the second light-emitting particle layer 22 and the third light-emitting particle layer 23, which form separate pairs, an energy transfer prevention layer 214 may be provided to separate the second light-emitting particle layer 22 and the third light-emitting particle layer 23.

[0068] The thickness of the energy transfer prevention layer 214 is preferably 15 nm or more and 1000 nm or less, and more preferably 20 nm or more and 500 nm or less. When the thickness is 15 nm or more, energy transfer between the second and third phosphor particles is prevented or reduced, improving the accuracy of the sensor. When the thickness is 1000 nm or less, the ability to follow minute irregularities is improved, improving the accuracy of the sensor.

[0069] The material of the energy transfer prevention layer 214 is not particularly limited as long as it is less compressed than the materials of the first and second spacer layers 212a, 212c and does not inhibit light emission, but examples thereof include silicon oxide-based materials.

[0070] The principle of displacement measurement by the displacement sensor 200 is the same as that in the first embodiment, and therefore a description thereof will be omitted.

[0071] Fig. 6 is a graph showing an emission spectrum from the recess 11 of the object 001. Fig. 7 is a graph showing an emission spectrum from the protrusion 12 of the object 001.

[0072] In the recess 11 of the object to be measured 001 in Fig. 5, the distance between the first luminescent particle 211 and the second luminescent particle 213 is sufficiently large, and the distance between the third luminescent particle 215 and the fourth luminescent particle 216 is also sufficiently large. In this state, as shown in Fig. 6, almost no transfer of excitation energy occurs from the second luminescent particle 213 to the first luminescent particle 211, and almost no transfer of excitation energy occurs from the fourth luminescent particle 216 to the fifth luminescent particle, so that the emission 16b of the first luminescent particle 211 is slight. For this reason, the excitation energy is absorbed by the excitation energy absorber 212b, and therefore the emission spectrum 16a of the second luminescent particle 213, the emission spectrum 18b of the third luminescent particle 215, and the emission spectrum 18a of the fourth luminescent particle 216 are obtained (Fig. 6). Since the excitation energy absorber 212b is provided only on the first spacer layer 212a, it is preferable that the emission 18b of the third phosphor particles 215 has a lower emission intensity than the emission spectrum 18a of the fourth phosphor particles 216 (FIG. 6).

[0073] On the other hand, in the convex portion 12 of the object to be measured 001 in FIG. 5, the distance between the first light-emitting particle 211 and the second light-emitting particle 213 becomes short, and the distance between the third light-emitting particle 215 and the fourth light-emitting particle 216 becomes short. In this state, as shown in FIG. 7, the second light-emitting particle 213 is excited according to the distance between the first light-emitting particle 211 and the second light-emitting particle 213, and before the second light-emitting particle 213 emits light, energy transfer (FRET) occurs from the second light-emitting particle 213 to the first light-emitting particle 211, and the energy that would have been emitted from the second light-emitting particle 213 is used for the emission of light by the first light-emitting particle 211. As a result, as shown in FIG. 7, the emission spectrum intensity 16a of the second light-emitting particle 213 decreases, and the emission spectrum 16b of the first light-emitting particle 211 appears (FIG. 7). Similarly, the emission spectrum intensity 18a of the fourth light-emitting particle 216 decreases, and the emission spectrum 16b of the third light-emitting particle 215 increases. That is, in the overall emission spectrum of the four first to fourth light-emitting particles 211, 213, 215, 216, the emission spectrum intensity 16a of the second light-emitting particle 213 on the short wavelength side and the emission spectrum intensity 18a of the fourth light-emitting particle 216 are decreased compared to the case of a single particle, the emission spectrum intensity 16b of the first light-emitting particle 211 on the long wavelength side newly appears, and the emission spectrum intensity 18b of the third light-emitting particle 215 is increased, resulting in a wavelength distribution. The behavior of the wavelength distribution in the overall emission spectrum changes depending on the distance between the second and first light-emitting particles 213, 211 and the distance between the fourth and third light-emitting particles 216, 215.

[0074] Furthermore, since the displacement of the object to be measured 001 in the Z direction is substantially the same as the displacement of the distance between the second and first luminescent particles 213, 211 and the displacement of the distance between the fourth and third luminescent particles 216, 215, the displacement can be measured with higher accuracy by measuring two pairs of distances.

[0075] In addition, the present disclosure includes appropriate combinations of any of the various embodiments and / or examples described above, and can achieve the effects of each embodiment and / or example. [Industrial Applicability]

[0076] The displacement measurement system according to the present disclosure enables easy measurement of displacement or pressure in a microscopic area with high accuracy, and is capable of measuring objects that may be deteriorated by ultraviolet rays. The displacement measurement system according to the present disclosure can also be used to measure minute scratches or irregularities on optical lenses, precision-machined parts, etc. [Explanation of symbols]

[0077] 001 Object to be measured 10, 10a Displacement measurement system 11 Recess 12 Convex part 13 Excitation light 14 Lighting 15a Emission spectrum from the recess 15b Emission spectrum from the convex part 16a Emission spectrum of the second particle 16b Emission spectrum of the first particle 18a Emission spectrum of the fourth particle 18b Emission spectrum of the third particle 20 Pressure member 21 First luminescent particle layer 22 Second luminescent particle layer 23 Third luminescent particle layer 24 Fourth luminescent particle layer 100 light sources 200, 201 Displacement sensor 211 Luminous particles, first luminous particles 212a First spacer layer 212b Excitation energy absorber 212c second spacer layer 213 Luminous particles, second luminous particles 214 Energy transfer inhibitors 215 Luminous particles, third luminous particles 216 Luminous Particles, Fourth Luminous Particles 220 Support 300 Light emitting / receiving element 400 Image Analysis Unit

Claims

1. a first light-emitting particle layer provided so as to be in contact with the object to be measured, in which first light-emitting particles that emit light at a first wavelength in response to excitation energy are distributed over at least one dimension; a second light-emitting particle layer in which second light-emitting particles that emit light at a second wavelength different from the first wavelength in response to the excitation energy are distributed across the area; a spacer layer that separates the first and second luminescent particle layers in a direction intersecting the extension and includes an excitation energy absorbing material that absorbs the excitation energy; A displacement sensor comprising:

2. 2. The displacement sensor according to claim 1, wherein an emission spectrum of one type of light-emitting particle of the first light-emitting particles and an absorption spectrum of the other type of light-emitting particle overlap with each other.

3. 3. The displacement sensor according to claim 1, wherein the first and second phosphor particles are made of at least one of semiconductor nanoparticles and organic dyes.

4. 4. The displacement sensor according to claim 1, wherein the second light-emitting particles, which are spaced apart from the first light-emitting particles on the surface in contact with the object to be measured across the spacer layer, have a short emission peak wavelength.

5. a first light-emitting particle layer provided so as to be in contact with the object to be measured, in which first light-emitting particles that emit light at a first wavelength in response to excitation energy are distributed over at least one dimension; a second light-emitting particle layer in which second light-emitting particles that emit light at a second wavelength different from the first wavelength in response to the excitation energy are distributed across the area; a first sintered body including an excitation energy absorber that separates the first and second luminescent particle layers from each other in a direction intersecting the extension; Pacer layer and a third luminescent particle layer in which third luminescent particles that emit light at a third wavelength different from the first and second wavelengths in response to the excitation energy are distributed across the area; a fourth luminescent particle layer in which fourth luminescent particles that emit light at a fourth wavelength different from the first, second, and third wavelengths in response to the excitation energy are distributed across the area; a second spacer layer that separates the third and fourth phosphor particle layers in a direction intersecting the extension; an energy transfer prevention layer that separates the second and third luminescent particle layers in a direction intersecting the extension; Including, A displacement sensor configured by stacking the first luminescent particle layer, the first spacer layer, the second luminescent particle layer, the energy transfer prevention layer, the third luminescent particle layer, the second spacer layer, and the fourth luminescent particle layer in this order.

6. 6. The displacement sensor according to claim 5, wherein an emission spectrum of one type of light-emitting particle of the first light-emitting particles and the second light-emitting particles overlaps with an absorption spectrum of the other type of light-emitting particle.

7. 7. The displacement sensor according to claim 5, wherein the first and second phosphor particles are made of at least one of semiconductor nanoparticles and organic dyes.

8. 8. The displacement sensor according to claim 5, wherein the second light-emitting particles, which are spaced apart from the first light-emitting particles on the contact surface with the object to be measured across the first spacer layer, have a light-emitting peak wavelength that is a short wavelength.

9. A displacement measurement system using the displacement sensor according to any one of claims 1 to 8.

10. A pressure measurement system using the displacement sensor according to any one of claims 1 to 8.

11. The displacement sensor according to any one of claims 1 to 8; an excitation energy source that causes the first and second light-emitting particles included in the displacement sensor to emit light; a light receiving unit that receives light emitted from the displacement sensor; A displacement measurement system comprising:

Images