Liquid crystal element and method for manufacturing the same

Abstract

The purpose of an embodiment of the present invention is to provide a manufacturing method for a liquid crystal element with stretchability.　According to one embodiment of the present invention, a manufacturing method for a liquid crystal element comprises forming an alignment layer on a base, forming a cholesteric liquid crystal layer on the alignment layer, forming an adhesive layer on the cholesteric liquid crystal layer, attaching a stretchable substrate with the adhesive layer, and peeling off the cholesteric liquid crystal layer from the alignment layer.

Description

Technical Field

[0001] Embodiments of the present invention relate to a liquid crystal element and a method for manufacturing the liquid crystal element.

Background Art

[0002] In recent years, various liquid crystal elements using cholesteric liquid crystals have been studied. Cholesteric liquid crystals have the property of reflecting light of a specific wavelength depending on the helical pitch. In one example, a composite structure including a cholesteric liquid crystal elastomer between a pair of substrates has been proposed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present embodiment is to provide a liquid crystal element having stretchability and a manufacturing method capable of easily manufacturing this liquid crystal element.

Means for Solving the Problems

[0005] According to one embodiment, a method for manufacturing a liquid crystal element includes: forming an alignment layer on a support, forming a cholesteric liquid crystal layer on the alignment layer, forming an adhesive layer on the cholesteric liquid crystal layer, adhering a stretchable substrate with the adhesive layer, and peeling the cholesteric liquid crystal layer from the alignment layer. According to one embodiment, a liquid crystal element includes: a stretchable substrate, an adhesive layer disposed on the substrate, and a first cholesteric liquid crystal layer including a plasticizer and adhered to the adhesive layer and having stretchability.

Effects of the Invention

[0006] According to one embodiment, it is possible to provide a stretchable liquid crystal element and a manufacturing method capable of easily manufacturing this liquid crystal element.

Brief Description of the Drawings

[0007]

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Embodiments for Carrying Out the Invention

[0008] Hereinafter, this embodiment will be described with reference to the drawings. Note that the disclosure is merely an example, and for those skilled in the art, obvious appropriate modifications that maintain the gist of the invention are naturally included in the scope of the present invention. Also, for the purpose of making the description clearer, the drawings may schematically represent the width, thickness, shape, etc. of each part compared to the actual aspect, but this is merely an example and does not limit the interpretation of the present invention. Further, in this specification and each drawing, components that exhibit the same or similar functions as those described above with respect to the previously shown drawings may be given the same reference numerals, and detailed descriptions that are redundant may be omitted as appropriate. Note that, in the drawings, for ease of understanding as necessary, an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other are described. The direction along the X-axis is referred to as the X direction or the first direction, the direction along the Y-axis is referred to as the Y direction or the second direction, and the direction along the Z-axis is referred to as the Z direction or the third direction. The plane defined by the X-axis and the Y-axis is referred to as the X-Y plane. Looking at the X-Y plane is referred to as a plan view. The first direction X and the second direction Y correspond to, for example, directions parallel to the main surface of the substrate included in the liquid crystal element 100, and the third direction Z corresponds to the thickness direction of the liquid crystal element 100.

[0009] FIG. 1 is a cross-sectional view showing an example of the liquid crystal element 100 according to this embodiment. The liquid crystal element 100 includes a substrate 11, an adhesive layer 12, and a cholesteric liquid crystal layer (first cholesteric liquid crystal layer) 13. The adhesive layer 12 is located between the substrate 11 and the cholesteric liquid crystal layer 13 in the third direction Z.

[0010] The substrate 11 is a resin substrate having stretchability. Also, the substrate 11 is, for example, transparent. As materials for forming the substrate 11, for example, rubber materials such as silicone rubber, fluorine rubber, chloroprene rubber, nitrile rubber, ethylene propylene rubber, thermoplastic elastomers such as polystyrene-based, olefin / alkene-based, polyvinyl chloride-based, polyurethane-based, polyester-based, polyamide-based, and other resins having rubber (elastomer) - like properties are applicable.

[0011] The substrate 11 has a main surface (inner surface) 11A and a main surface (outer surface) 11B on the opposite side of the main surface 11A. The main surface 11A and the main surface 11B are planes parallel to the X-Y plane. The substrate 11 has a thickness T11 in the third direction Z.

[0012] The adhesive layer 12 is disposed on the substrate 11 and is in contact with the main surface 11A. Also, the adhesive layer 12 is, for example, transparent. The adhesive layer 12 has elasticity, similar to the substrate 11. As the material for forming the adhesive layer 12, for example, adhesives such as acrylic resins, enethiol resins, epoxy resins, silicone resins, polyvinyl alcohol resins, polyvinyl acetal resins, polyvinyl butyral resins, and optical adhesive sheets are applicable. The material of the adhesive layer 12 is appropriately selected according to the physical properties of the material of the substrate 11 and the like.

[0013] The adhesive layer 12 has a thickness T12 in the third direction Z. The thickness T12 is smaller than the thickness T11.

[0014] The cholesteric liquid crystal layer 13 is adhered to the adhesive layer 12. The cholesteric liquid crystal layer 13 has elasticity, similar to the substrate 11. The cholesteric liquid crystal layer 13 is formed, for example, using a mixture in which a plasticizer and a crosslinking agent are added to a polymerizable liquid crystal monomer, a polymerizable chiral liquid crystal monomer, and a photoinitiator.

[0015] As the photoinitiator, for example, alkylphenone-based photoinitiators (Omnirad 651), acylphosphine oxide-based photoinitiators (Omnirad TPO H), intramolecular hydrogen abstraction-type photoinitiators (Omnirad MBF), intramolecular hydrogen abstraction-type photoinitiators (Irgacure OXE01), cationic photoinitiators (Omnirad 250), etc. are applicable.

[0016] As the plasticizer, for example, single-component nematic liquid crystals such as 4-cyano-4'-pentylbiphenyl (5CB), or nematic liquid crystals composed of multiple components are applicable.

[0017] As the crosslinking agent, 1,6 - hexanediol diacrylate, 1,4 - butanediol diacrylate, trimethylolpropane triacrylate, etc. are applicable.

[0018] The cholesteric liquid crystal layer 13 has a main surface (inner surface) 13A in contact with the adhesive layer 12 and a main surface (outer surface) 13B on the opposite side of the main surface 13A. The main surface 13A and the main surface 13B are surfaces substantially parallel to the X - Y plane. The cholesteric liquid crystal layer 13 has a thickness T13 in the third direction Z. The thickness T13 is smaller than the thickness T12. The thickness T13 is, for example, 1 μm to 10 μm, preferably 2 μm to 7 μm.

[0019] The main surface 11B is in contact with a low - refractive - index medium having a refractive index smaller than that of the substrate 11. Similarly, the main surface 13B is in contact with a low - refractive - index medium having a refractive index smaller than that of the cholesteric liquid crystal layer 13. The low - refractive - index medium is, for example, air. These main surfaces 11B and 13B can form the light - incident surface of the liquid crystal element 100.

[0020] As shown schematically in an enlarged view, the cholesteric liquid crystal layer 13 has cholesteric liquid crystal (first cholesteric liquid crystal) 311 that twists in the first twisting direction. The cholesteric liquid crystal 311 has a helical axis AX1 substantially parallel to the third direction Z and also has a helical pitch P11 along the third direction Z. The helical pitch P11 indicates one period of the helix (the layer thickness along the helical axis AX1 required for the liquid crystal molecules to rotate 360 degrees).

[0021] The cholesteric liquid crystal layer 13 has a reflective surface 321. At the reflective surface 321, among the incident light to the cholesteric liquid crystal layer 13, circularly polarized light in the selective reflection wavelength band determined according to the helical pitch and refractive index anisotropy is reflected. For example, when the first turning direction is clockwise, clockwise circularly polarized light is reflected by the reflective surface 321, and when the first turning direction is counterclockwise, counterclockwise circularly polarized light is reflected by the reflective surface 321. Note that in this specification, "reflection" in the cholesteric liquid crystal layer 13 involves diffraction inside the cholesteric liquid crystal layer 13. Also, in this specification, the circularly polarized light may be strict circularly polarized light or circularly polarized light approximated to elliptically polarized light.

[0022] According to such an embodiment of the present invention, a stretchable liquid crystal element 100 can be provided.

[0023] FIG. 2 is a cross-sectional view showing another example of the liquid crystal element 100 according to this embodiment. The example shown in FIG. 2 is different from the example shown in FIG. 1 in that the liquid crystal element 100 includes a cholesteric liquid crystal layer (second cholesteric liquid crystal layer) 14 disposed on the cholesteric liquid crystal layer (first cholesteric liquid crystal layer) 13. The cholesteric liquid crystal layer 14 is formed of the same material as the cholesteric liquid crystal layer 13 and has stretchability.

[0024] The cholesteric liquid crystal layer 14 has a main surface (inner surface) 14A and a main surface (outer surface) 14B on the opposite side of the main surface 14A. The main surface 14A and the main surface 14B are surfaces substantially parallel to the X-Y plane. The main surface 14B can form a light incident surface. Note that an alignment film or an adhesive layer may be interposed between the cholesteric liquid crystal layer 13 and the cholesteric liquid crystal layer 14.

[0025] As shown schematically on an enlarged scale, the cholesteric liquid crystal layer 14 has a cholesteric liquid crystal (second cholesteric liquid crystal) 312 that rotates in a second rotation direction opposite to the first rotation direction. The cholesteric liquid crystal 312 has a helical axis AX2 substantially parallel to the third direction Z, and also has a helical pitch P12 along the third direction Z. The helical axis AX2 is parallel to the helical axis AX1. The helical pitch P12 is equivalent to the helical pitch P11. The helical pitch P12 may be different from the helical pitch P11. The cholesteric liquid crystal layer 14 has a reflecting surface 322.

[0026] In the liquid crystal element 100 of such an example, the reflecting surface 321 of the cholesteric liquid crystal layer 13 reflects the first circularly polarized light corresponding to the first rotation direction of the cholesteric liquid crystal 311 among the selective reflection wavelength bands. Also, the reflecting surface 322 of the cholesteric liquid crystal layer 14 reflects the second circularly polarized light corresponding to the second rotation direction of the cholesteric liquid crystal 312 among the selective reflection wavelength bands.

[0027] When the helical pitch P11 and the helical pitch P12 are equivalent to each other, the selective reflection wavelength band of the cholesteric liquid crystal 311 is equivalent to the selective reflection wavelength band of the cholesteric liquid crystal 312. For this reason, the first circularly polarized light and the second circularly polarized light of the selective reflection wavelength band can be reflected, and the reflectance of the selective reflection wavelength band can be improved.

[0028] When the helical pitch P11 and the helical pitch P12 are different from each other, the selective reflection wavelength band of the cholesteric liquid crystal 311 is different from the selective reflection wavelength band of the cholesteric liquid crystal 312. For this reason, the selective reflection wavelength band of the liquid crystal element 100 can be broadened.

[0029] FIG. 3 is a diagram for explaining an example of the cholesteric liquid crystal 311 included in the cholesteric liquid crystal layer 13. In addition, in FIG. 3, the cholesteric liquid crystal layer 13 is illustrated with an enlarged view in the third direction Z. Also, for simplicity, among the liquid crystal molecules LM1 constituting the cholesteric liquid crystal 311, one liquid crystal molecule LM1 located in the same plane parallel to the X-Y plane is illustrated. The alignment direction of the illustrated liquid crystal molecule LM1 corresponds to the average alignment direction of the plurality of liquid crystal molecules located in the same plane.

[0030] Focusing on one cholesteric liquid crystal 311, the cholesteric liquid crystal 311 is composed of a plurality of liquid crystal molecules LM1 stacked in a spiral shape along the Z direction while rotating. The plurality of liquid crystal molecules LM1 have a liquid crystal molecule LM11 on one end side of the cholesteric liquid crystal 311 and a liquid crystal molecule LM12 on the other end side of the cholesteric liquid crystal 311. The liquid crystal molecule LM11 is close to the main surface 13A or the adhesive layer 12. The liquid crystal molecule LM12 is close to the main surface 13B.

[0031] In the cholesteric liquid crystal layer 13 of the illustrated example, the alignment directions of a plurality of adjacent cholesteric liquid crystals 311 along the first direction X are aligned in one direction. That is, the alignment directions of a plurality of adjacent liquid crystal molecules LM11 along the first direction X are substantially the same as each other. Also, the alignment directions of a plurality of adjacent liquid crystal molecules LM12 along the first direction X are also substantially the same as each other.

[0032] The reflection surface 321 of the cholesteric liquid crystal layer 13 is formed in a planar shape extending along the X-Y plane. The reflection surface 321 here corresponds to a surface where the alignment directions of the liquid crystal molecules LM1 are aligned or a surface where the spatial phases are aligned (equiphase surface).

[0033] Such a cholesteric liquid crystal layer 13 is cured in a state where the alignment direction of the liquid crystal molecules LM1 is fixed. That is, the alignment direction of the liquid crystal molecules LM1 is not controlled according to an electric field. For this reason, the liquid crystal element 100 does not include an electrode for forming an electric field in the cholesteric liquid crystal layer 13.

[0034] FIG. 4 is a diagram for explaining another example of the cholesteric liquid crystal 311 included in the cholesteric liquid crystal layer 13. The example shown in FIG. 4 is different from the example shown in FIG. 3 in that the alignment directions of a plurality of adjacent cholesteric liquid crystals 311 along the first direction X are different from each other. And the alignment directions of the plurality of liquid crystal molecules LM11 continuously change along the first direction X. Also, the alignment directions of the plurality of liquid crystal molecules LM12 also continuously change along the first direction X. These alignment directions will be described later. The reflecting surface 321 of the cholesteric liquid crystal layer 13 is inclined with respect to the X-Y plane. The angle θ formed between the reflecting surface 321 and the X-Y plane is an acute angle.

[0035] FIG. 5 is a diagram showing an example of the alignment pattern of the liquid crystal molecules LM11 shown in FIG. 4. In the cholesteric liquid crystal layer 13, the alignment directions of the respective liquid crystal molecules LM11 arranged along the first direction X are different from each other. For example, focusing on five liquid crystal molecules LM11 arranged along the line A-A', the alignment directions of the respective liquid crystal molecules LM11 change by a certain angle clockwise along the first direction X (from left to right in the figure). Here, the amount of change in the alignment directions of adjacent liquid crystal molecules LM11 is constant along the first direction X, but it may gradually increase or gradually decrease.

[0036] Here, the interval between two liquid crystal molecules LM11 when the alignment direction of the liquid crystal molecules LM11 changes by 180 degrees along the first direction X is defined as the alignment pitch α1.

[0037] On the other hand, in the cholesteric liquid crystal layer 13, the alignment directions of the respective liquid crystal molecules LM11 arranged along the second direction Y substantially coincide. That is, the spatial phase in the X-Y plane of the cholesteric liquid crystal layer 13 continuously changes along the first direction X and is substantially constant in the second direction Y.

[0038] Next, taking the cholesteric liquid crystal layer 13 as an example, the optical action will be described.

[0039] FIG. 6 is a diagram for explaining the optical action of the cholesteric liquid crystal layer 13. On the left side of FIG. 6, the cholesteric liquid crystal layer 13 in the initial state (non-stretched state) is shown, and on the right side of the figure, the cholesteric liquid crystal layer 13 in the stretched state is shown.

[0040] Generally, the selective reflection wavelength band Δλ of the cholesteric liquid crystal 311 with respect to the vertically incident light is represented by "Δn*P" based on the helical pitch P of the cholesteric liquid crystal 311 and the refractive index anisotropy Δn (the difference between the refractive index ne for extraordinary light and the refractive index no for ordinary light). The specific wavelength range of the selective reflection wavelength band Δλ is in the range of (no*P~ne*P). The central wavelength λm of the selective reflection wavelength band Δλ is represented by "nav*P" based on the helical pitch P of the cholesteric liquid crystal 311 and the average refractive index nav (= (ne + no) / 2).

[0041] The cholesteric liquid crystal 311 in the initial state has the helical pitch P11 as described above. For example, the helical pitch P11 is set so as to reflect the first circularly polarized light of the red wavelength λR as the selective reflection wavelength band Δλ. Therefore, when the light Li is incident on the cholesteric liquid crystal layer 13, the light Lr reflected by the reflection surface 321 is the first circularly polarized light of the red wavelength λR. Other light LTt including the second circularly polarized light of the red wavelength λR passes through the reflection surface 321.

[0042] In the state where the cholesteric liquid crystal layer 13 is stretched along the first direction X, the cholesteric liquid crystal 311 has a helical pitch P2 smaller than the helical pitch P11. Therefore, when the light Li is incident on the cholesteric liquid crystal layer 13, the light Lr reflected by the reflection surface 321 is the first circularly polarized light having a shorter wavelength than the red wavelength λR, for example, the first circularly polarized light of the green wavelength λG. That is, the selective reflection wavelength band Δλ' in the stretched state shifts to the shorter wavelength side than the selective reflection wavelength band Δλ in the initial state. Other light LTt including the second circularly polarized light of the green wavelength λG passes through the reflection surface 321.

[0043] Since the cholesteric liquid crystal layer 13 has elasticity, when it is released from the stretched state, it returns to the initial state.

[0044] As described above, such an optical effect means that the cholesteric liquid crystal layer 13 has different selective reflection wavelength bands Δλ in the initial state and the stretched state (that is, the colors of the reflected light are different). That is, the color of the reflected light in the liquid crystal element 100 changes according to the amount of stretching and the amount of strain.

[0045] Next, a method for manufacturing the liquid crystal element 100 according to the present embodiment will be described with reference to FIGS. 7 and 8.

[0046] First, as shown in the upper part of FIG. 7, a cleaned support S is prepared. The support S is a non-stretchable substrate and is formed of a transparent inorganic glass such as non-alkali glass, soda-lime glass, borosilicate glass, or quartz glass, a transparent resin such as acrylic, polyethylene terephthalate, polycarbonate, or polyvinyl chloride, a colored inorganic glass, a colored resin, or the like. In one example, the support S is formed of non-alkali glass and has a thickness of 0.5 mm.

[0047] Subsequently, as shown in the middle part of FIG. 7, an alignment layer AL is formed on the support S. Here, one method for forming the alignment layer AL will be described. That is, a thin film is formed on the support S. The thin film here is formed of polyimide, polyvinyl alcohol, diamond-like carbon, or the like. Thereafter, an alignment treatment is performed on this thin film. As the alignment treatment, a rubbing treatment, an optical alignment treatment, or the like can be applied. As one method of the optical alignment treatment, there is a method of irradiating the thin film with ultraviolet rays of linearly polarized light. By applying this method, as described with reference to FIG. 3, an alignment pattern can be formed in which the alignment directions of the liquid crystal molecules adjacent to the alignment layer AL are aligned in one direction. In addition, as another method of the optical alignment treatment, there is a method of irradiating the thin film with an interference pattern of ultraviolet rays of right-circularly polarized light and left-circularly polarized light. By applying this method, as described with reference to FIG. 5, a complex alignment pattern can be formed in which the alignment directions of the liquid crystal molecules adjacent to the alignment layer AL change continuously. In one example, the thin film is a polyimide film and has a thickness of 100 nm. Photo-alignment treatment was applied as the alignment treatment.

[0048] Also, the alignment layer AL can be formed by other methods. That is, a photocurable resin is applied onto the support S, a mold with minute irregularities formed in advance is superposed on the photocurable resin, and after irradiating ultraviolet rays while applying pressure, the mold is removed. As a result, the photocurable resin cures into a shape corresponding to the irregularities of the mold, and a structure having minute irregularities is formed as the alignment layer AL. According to such a method, alignment treatment is unnecessary.

[0049] Subsequently, a cholesteric liquid crystal layer 13 is formed on the alignment layer AL. Here, one method for forming the cholesteric liquid crystal layer 13 will be described. That is, a liquid crystal mixture MX for forming the cholesteric liquid crystal layer 13 is prepared. The liquid crystal mixture MX is a mixture of a liquid crystal monomer, a chiral monomer, a plasticizer, a crosslinking agent, and a photoinitiator in a solvent. As the solvent, organic solvents such as hexane, cyclohexane, cyclohexanone, heptane, toluene, anisole, and propylene glycol monomethyl ether acetate (PGMEA) are applicable. Then, as shown in the lower part of FIG. 7, the liquid crystal mixture MX is applied onto the alignment layer AL. It is not necessary to superpose other members on the applied liquid crystal mixture MX. The liquid crystal molecules adjacent to the alignment layer AL are aligned in a predetermined direction by the alignment regulating force of the alignment layer AL. Thereafter, in a state where the liquid crystal mixture MX exhibits a cholesteric liquid crystal phase, the solvent is removed to temporarily cure the liquid crystal mixture MX, and ultraviolet rays are irradiated. As a result, a stretchable cholesteric liquid crystal layer 13 is formed. In one example, the cholesteric liquid crystal layer 13 has a thickness of about 4 μm in the initial state.

[0050] Subsequently, as shown in the upper part of FIG. 8, an adhesive layer 12 is formed on the cholesteric liquid crystal layer 13. In one example, as the adhesive layer 12, a material mainly composed of a modified silicone-based resin was applied. The thickness of the adhesive layer 12 coated on the cholesteric liquid crystal layer 13 is larger than the thickness of the cholesteric liquid crystal layer 13 (about 4 μm), for example, about 50 μm.

[0051] Subsequently, as shown in the middle part of FIG. 8, the stretchable substrate 11 is adhered by the adhesive layer 12. In one example, as the substrate 11, a film formed of transparent silicone rubber was applied. The substrate 11 has a thickness of 0.2 mm.

[0052] Subsequently, as shown in the lower part of FIG. 8, after the adhesive layer 12 is cured, the cholesteric liquid crystal layer 13 is peeled off from the alignment layer AL. The adhesive force between the alignment layer AL and the cholesteric liquid crystal layer 13 is smaller than the adhesive force between the adhesive layer 12 and the cholesteric liquid crystal layer 13. Therefore, the cholesteric liquid crystal layer 13 can be easily peeled off from the alignment layer AL without applying energy such as light or heat.

[0053] Through the above steps, the liquid crystal element 100 described with reference to FIG. 1 is manufactured.

[0054] According to the present embodiment, by transferring the cholesteric liquid crystal layer 13 formed on the non-stretchable support to the stretchable substrate 11, the stretchable liquid crystal element 100 can be easily manufactured. Further, in the process of forming the alignment layer AL, a complex alignment pattern can be formed by applying an optical alignment treatment.

[0055] FIG. 9 is a diagram showing an example of the reflection spectrum of the liquid crystal element 100 of the present embodiment. The horizontal axis of the figure is the wavelength (nm), and the vertical axis of the figure is the reflectance (%). The reflection spectrum shown here is the result of measurement for the liquid crystal element 100 in the initial state.

[0056] The refractive index anisotropy Δn of the cholesteric liquid crystal 311 is 0.2. The selective reflection wavelength band Δλ is approximately 70 nm based on the measurement results of the reflection spectrum. Therefore, the helical pitch P of the cholesteric liquid crystal layer 311 is estimated to be approximately 350 nm.

[0057] In the liquid crystal element 100, when there is a requirement to make the change in the color of the reflected light prominent in response to a slight change in the amount of elongation, it is desirable that the selective reflection wavelength band Δλ be small. To achieve this, it is required to reduce the refractive index anisotropy Δn or reduce the helical pitch P. The refractive index anisotropy Δn is, for example, in the range of 0.05 to 0.25, preferably in the range of 0.05 to 0.15, and more preferably in the range of 0.05 to 0.1. The helical pitch P can be adjusted by the material and molar ratio of the chiral monomer mixed in the process of manufacturing the cholesteric liquid crystal layer 13.

[0058] 《Application Example》 FIG. 10 is a cross-sectional view for explaining an application example of the liquid crystal element 100. On the left side of FIG. 10, the liquid crystal element 100 in the initial state (non-elongated state) is shown, and on the right side of FIG. 10, the liquid crystal element 100 in the elongated state is shown.

[0059] The liquid crystal element 100 includes a light-emitting element 51 and a light-receiving element 52. The light-emitting element 51 and the light-receiving element 52 are disposed between the substrate 11 and the cholesteric liquid crystal layer 13. The light-emitting element 51 is configured to emit white light toward the cholesteric liquid crystal layer 13. The light-receiving element 52 is configured to output an electrical signal according to the wavelength and intensity of the detected visible light.

[0060] The liquid crystal element 100 in the initial state is set to reflect the first circularly polarized light of the red wavelength λR at the reflection surface 321 of the cholesteric liquid crystal layer 13. Therefore, when the white light Li emitted from the light-emitting element 51 is incident on the cholesteric liquid crystal layer 13, the light Lr, which is the first circularly polarized light of the red wavelength λR, is reflected by the reflection surface 321. The other light Lt passes through the reflection surface 321. The light-receiving element 52 detects the light Lr reflected by the reflection surface 321 and outputs an electrical signal according to the wavelength and intensity of the light Lr.

[0061] In the stretched liquid crystal element 100, at the reflection surface 321 of the cholesteric liquid crystal layer 13, the first circularly polarized light with a wavelength shorter than the red wavelength is reflected. Therefore, when the white light Li emitted from the light-emitting element 51 enters the cholesteric liquid crystal layer 13, for example, the light Lr which is the first circularly polarized light of the green wavelength λG is reflected by the reflection surface 321. The other light Lt passes through the reflection surface 321. The light-receiving element 52 detects the light Lr reflected by the reflection surface 321 and outputs an electrical signal corresponding to the wavelength and intensity of the light Lr.

[0062] The light-receiving element 52 is connected to the host computer. In the host computer, based on the electrical signal output from the light-receiving element 52, it is possible to detect whether the liquid crystal element 100 is in the initial state or the stretched state. Further, when the liquid crystal element 100 is in the stretched state, in the host computer, based on the electrical signal output from the light-receiving element 52, the amount of stretch of the liquid crystal element 100 can be detected.

[0063] As described above, according to the present embodiment, it is possible to provide a stretchable liquid crystal element and a manufacturing method capable of easily manufacturing this liquid crystal element.

[0064] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

Explanation of Reference Numerals

[0065] 100... Liquid crystal element 11... Substrate 12... Adhesive layer 13... First cholesteric liquid crystal layer 311... First cholesteric liquid crystal 14…Second cholesteric liquid crystal layer 312…Second cholesteric liquid crystal S…Support AL…Alignment layer

Claims

1. A substrate having elasticity, An adhesive layer disposed on the substrate, A first cholesteric liquid crystal layer containing a plasticizer, adhered to the adhesive layer, and having elasticity, A light-emitting element and a light-receiving element disposed between the substrate and the first cholesteric liquid crystal layer, A liquid crystal element comprising the above.

2. Further comprising a second cholesteric liquid crystal layer disposed on the first cholesteric liquid crystal layer, The cholesteric liquid crystals contained in each of the first cholesteric liquid crystal layer and the second cholesteric liquid crystal layer are twisted in opposite directions and have the same helical pitch. The liquid crystal element according to Claim 1.

3. The substrate is formed of a rubber material or a thermoplastic elastomer. The liquid crystal element according to Claim 1.

4. The adhesive layer is formed of any one of an acrylic resin, an enethiol resin, an epoxy resin, a silicone resin, a polyvinyl alcohol resin, a polyvinyl acetal resin, and a polyvinyl butyral resin. The liquid crystal element according to Claim 1.

5. The first cholesteric liquid crystal layer contains, as the plasticizer, a single-component nematic liquid crystal or a multi-component nematic liquid crystal. The liquid crystal element according to Claim 1.

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