Switch device

Abstract

This switch device (1) includes a glass layer (10), a clear layer (20) disposed on the lower surface (10b) side of the glass layer (10), and a switch (60) disposed on the lower surface side of the clear layer (20). The thickness of the glass layer (10) is 20-150 μm inclusive. The irregularity numerical value of a reflected image generated by light incident from the glass layer (10) side is 5 or less. When the glass layer (10) is pressed, the glass layer (10) and the clear layer (20) are elastically deformed and the switch (60) switches between conduction and non-conduction.

Description

Switching device

[0001] The present invention relates to a switch device.

[0002] A known switch device includes a glass layer and a switch disposed on the underside of the glass layer, the glass layer having a thickness of 20 μm to 150 μm, the switch having multiple contacts including a contact that can move up and down, and when the glass layer is pressed, the glass layer elastically deforms, switching the multiple contacts between conductive and non-conductive. In such a switch device, from the viewpoint of enhancing the texture, it is preferable that the reflected image generated by light incident from the glass layer side has little unevenness.

[0003] Japanese Patent Application Laid-Open No. 2022-166480

[0004] An object of the present invention is to provide a switch device that suppresses unevenness in the reflected image.

[0005] A switch device according to one embodiment of the present disclosure includes a glass layer, a clear layer disposed on the underside of the glass layer, and a switch disposed on the underside of the clear layer, wherein the thickness of the glass layer is 20 μm or more and 150 μm or less, a reflection image generated by light incident from the glass layer side has an unevenness value of 5 or less, and when the glass layer is pressed, the glass layer and the clear layer elastically deform, switching the switch between conductive and non-conductive states.

[0006] According to the disclosed technology, it is possible to provide a switch device that suppresses unevenness in the reflected image.

[0007] It is a cross-sectional view illustrating the switch device according to the first embodiment. It is a plan view of the printed film shown in FIG. 1. It is a diagram explaining the operation of the switch device according to the first embodiment. It is a diagram explaining a reflected image. It is a diagram explaining an example and a comparative example.

[0008] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes the preferred embodiments of the present invention with reference to the accompanying drawings. In the drawings, the same components are designated by the same reference numerals, and redundant explanations may be omitted.

[0009] 1 is a cross-sectional view illustrating a switch device according to a first embodiment. As shown in FIG. 1, the switch device 1 includes a glass layer 10, a clear layer 20, a printed film 30, a bonding layer 40, a support portion 50, and a switch 60.

[0010] The components of the switch device 1 will be described below.

[0011] [Glass Layer] The glass layer 10 has an upper surface 10a and a lower surface 10b opposite to the upper surface 10a. The upper surface 10a is a single continuous surface. The lower surface 10b is also a single continuous surface. The upper surface 10a side of the glass layer 10 forms the outermost surface of the switch device 1. The glass layer 10 preferably has high surface durability as determined by a pencil hardness test of 9H or higher and excellent dimensional stability.

[0012] The glass layer 10 is not particularly limited, and an appropriate glass layer can be adopted depending on the purpose. The glass layer 10 can be classified by composition, for example, soda-lime glass, borate glass, aluminosilicate glass, quartz glass, etc. Furthermore, the glass layer 10 can be classified by alkali component, for example, alkali-free glass or low-alkali glass. The alkali metal component (e.g., Na) of the glass can be used. ２ O.K. ２ O, Li ２ The content of O) is preferably 15% by weight or less, and more preferably 10% by weight or less.

[0013] Considering the surface hardness, airtightness, and corrosion resistance of glass, the thickness of the glass layer 10 is preferably 20 μm or more. Furthermore, because the glass layer 10 needs to have film-like flexibility and durability against repeated use, the thickness of the glass layer 10 is preferably 150 μm or less. The thickness of the glass layer 10 is more preferably 30 μm to 120 μm, and particularly preferably 50 μm to 100 μm.

[0014] The glass layer 10 preferably has a light transmittance of 85% or more at a wavelength of 550 nm. The glass layer 10 preferably has a refractive index of 1.4 to 1.65 at a wavelength of 550 nm. The glass layer 10 preferably has a density of 2.3 g / cm ３ ~3.0 g / cm３ and more preferably 2.3 g / cm ３ ~2.7g / cm ３ is.

[0015] The method for forming the glass layer 10 is not particularly limited, and an appropriate method can be adopted depending on the purpose. Typically, the glass layer 10 can be produced by melting a mixture containing a main raw material such as silica or alumina, an antifoaming agent such as mirabilite or antimony oxide, and a reducing agent such as carbon at a temperature of approximately 1400°C to 1600°C, forming it into a thin plate, and then cooling it. Examples of methods for forming the glass layer 10 include the slot downdraw method, the fusion method, and the float method. The glass layer formed into a plate shape by these methods may be chemically polished with a solvent such as hydrofluoric acid, as necessary, to make it thinner or to improve smoothness.

[0016] The glass layer 10 may be made of tempered glass. The tempered glass may be chemically tempered glass or thermally tempered glass, but chemically tempered glass having a compressive stress layer is easier to manufacture than thermally tempered glass. When the glass layer 10 is made of tempered glass, it is preferable that the compressive stress be 600 MPa or more.

[0017] Chemical strengthening refers to the process of replacing ions near the surface of a glass sheet with ions with a larger ionic radius. This ion exchange creates a compressive stress layer on the surface of the glass sheet, resulting in chemically strengthened glass. The glass composition in the compressive stress layer is different from the glass composition inside the glass.

[0018] In chemically strengthened glass, the glass plate before strengthening can be, for example, soda-lime glass, aluminosilicate glass, borosilicate glass, aluminoborosilicate glass, etc. Soda-lime glass or soda-silicate glass is preferred, and soda-lime glass is more preferred, in that the depth of the compressive stress layer does not become too large more than necessary.

[0019] Ion exchange can be performed, for example, by substituting Li ions on the surface of the glass plate with Na ions and / or K ions. Alternatively, Na ions on the surface of the glass plate may be substituting K ions. By such ion exchange, a compressive stress layer is formed on the surface of the glass plate.

[0020] In the case of substituting Na ions with K ions, for example, a glass plate containing sodium may be brought into contact with an inorganic molten salt containing potassium nitrate. ２ CO ３ , Na ２ CO ３ , KHCO ３ , NaHCO ３ It is preferable that the solution contains at least one salt selected from the group consisting of KOH and NaOH.

[0021] A functional layer such as an antifouling layer, an anti-reflection layer, a conductive layer, a reflective layer, or a decorative layer may be provided on the upper surface 10a and / or the lower surface 10b of the glass layer 10. Braille may also be provided on the upper surface 10a of the glass layer 10. In the switch device according to this embodiment, the glass layer 10 is located on the outermost surface. Here, "the glass layer 10 is located on the outermost surface" means that the glass layer 10 is substantially located on the outermost surface. Even if an additional layer such as that described above is provided, this embodiment expresses the glass layer 10 as being located on the outermost surface.

[0022] [Clear Layer] The clear layer 20 is disposed on the lower surface 10b side of the glass layer 10. In addition to reinforcing the glass, the clear layer 20 functions to enhance the presence of the glass layer 10 and create a sense of depth when the switch device 1 is viewed from above. From the viewpoint of enhancing the presence and creating a sense of depth of the glass layer 10, the thickness of the clear layer 20 is preferably 250 μm or more and 1500 μm or less, and more preferably 600 μm or more and 1500 μm or less. The clear layer 20 is flexible. On the other hand, if a sense of depth is not required, the thickness of the clear layer 20 is 250 μm or less. Considering the effect of reinforcement alone, the thickness of the clear layer 20 is preferably 50 μm or more, and more preferably 100 μm or more.

[0023] The clear layer 20 preferably includes a transparent adhesive layer. The clear layer 20 can be composed of, for example, only a transparent adhesive layer. The clear layer 20 may have a laminated structure of a transparent resin layer and a transparent adhesive layer. In this case, the transparent resin layer is disposed on the glass layer 10 side. The transparent resin layer may have a laminated structure of a plurality of resin layers. The transparent adhesive layer may have a laminated structure of a plurality of adhesive layers.

[0024] When the clear layer 20 has a laminated structure of a transparent resin layer and a transparent adhesive layer, it is preferable that the thickness of the highly flexible transparent adhesive layer be thicker than that of the transparent resin layer, from the viewpoint of maintaining flexibility while improving the presence of the glass layer and providing a good sense of depth. The thickness of the transparent resin layer can be, for example, 50 μm or more and 150 μm or less. The thickness of the transparent adhesive layer can be, for example, 1.5 times or more the thickness of the transparent resin layer.

[0025] Examples of materials for the transparent resin layer that constitutes the clear layer 20 include polyester resins such as polyethylene terephthalate resins and polyethylene naphthalate resins, cycloolefin resins such as norbornene resins, polyethersulfone resins, polycarbonate resins, acrylic resins, polyolefin resins, polyimide resins, polyamide resins, polyimideamide resins, polyarylate resins, polysulfone resins, polyetherimide resins, and urethane resins.

[0026] Examples of materials for the transparent adhesive layer that constitutes the clear layer 20 include OCA (optically transparent adhesive). The adhesive material contained in the OCA layer is not particularly limited, and includes, for example, a (meth)acrylic polymer, a silicone polymer, a polyester, a polyurethane, a polyamide, a polyether, a fluorine-based polymer, a rubber-based polymer, or the like as a base polymer. In particular, a (meth)acrylic polymer is preferred, as it can suppress unevenness in the reflected image.

[0027] The storage modulus of the pressure-sensitive adhesive at 25° C. is preferably 0.1 MPa or more and 0.4 MPa or less. The storage modulus of the pressure-sensitive adhesive at 25° C. is more preferably 0.1 MPa or more and 0.3 MPa or less, and even more preferably 0.1 MPa or more and 0.2 MPa or less. By satisfying the above storage modulus range, the transparent adhesive layer has a certain degree of softness and can deform to follow the unevenness of the member, thereby reducing unevenness in the reflected image.

[0028] The transparent adhesive layer constituting the clear layer 20 preferably has a high surface smoothness. High surface smoothness of the transparent adhesive layer can reduce unevenness in the reflected image caused by light incident from the glass layer 10 side. As a result, the texture of the switch device 1 can be improved. The thicker the transparent adhesive layer, the better the smoothness obtained. The thickness of the transparent adhesive layer is preferably 150 μm or more. The thickness of the transparent adhesive layer is more preferably 200 μm or more. If the thickness of the transparent adhesive layer is 150 μm or more, it has a thickness that is thick enough to tolerate unevenness in the component, and therefore good smoothness can be obtained. Furthermore, if the thickness of the transparent adhesive layer is too thick, the click feeling will be reduced, so the thickness of the transparent adhesive layer is preferably 500 μm or less.

[0029] The clear layer 20 also has the function of improving the durability of the glass layer 10. Specifically, when the glass layer 10 and the clear layer 20 are laminated together, the clear layer 20 suppresses excessive deformation of the glass layer 10, which has the effect of suppressing cracking of the glass layer 10, and also realizes an appropriate amount of deformation, thereby improving the durability of the glass layer 10 when it is repeatedly elastically deformed. The amount of deformation of the glass layer 10 can be controlled by changing the thickness of the clear layer 20.

[0030] [Printed Film] The printed film 30 is disposed on the lower surface side of the clear layer 20. The printed film 30 is flexible. From the viewpoint of flexibility, the thickness of the printed film 30 can be, for example, 50 μm or more and 150 μm or less. In this case, the printed surface of the printed film 30 may be on the upper or lower surface of the film. However, if it is on the lower surface, the printed film 30 must be transparent, and there is no problem as long as it is made of the same material as the clear layer 20. If it is desired to further add the effect of a clear layer with a similar configuration, the printed surface is naturally disposed on the lower surface.

[0031] The printed film 30 is a film on which a pictorial symbol related to the operation of the switch 60 is printed in a position overlapping the switch 60 when viewed from the top surface 10a of the glass layer 10 so that the pictorial symbol is visible. FIG. 2 is a plan view illustrating an example of a printed film. In the example of FIG. 2, a pictorial symbol consisting of a triangle inside a circle is printed on the surface of a resin film or the like. This pictorial symbol is easily visible from the top surface 10a of the glass layer 10 through the glass layer 10 and the clear layer 20. This pictorial symbol can be used, for example, to start music playback in an audio device. From the standpoint of visibility, the visible light transmittance of the glass layer 10 and the clear layer 20 is preferably 80% or more. The visible light transmittance can be measured in accordance with JIS K7361-1.

[0032] [Bonding Layer] The bonding layer 40 bonds the printing film 30 and the support part 50. Any pressure-sensitive adhesive or adhesive can be used as the bonding layer 40. The thickness of the bonding layer 40 can be, for example, 5 μm or more and 20 mm or less.

[0033] In this specification, a pressure-sensitive adhesive refers to a layer that has adhesive properties at room temperature and adheres to an adherend with light pressure. Therefore, even when an adherend that has been stuck to the pressure-sensitive adhesive is peeled off, the pressure-sensitive adhesive retains practical adhesive strength. On the other hand, an adhesive refers to a layer that can bond substances by being interposed between them. Therefore, when an adherend that has been stuck to the adhesive is peeled off, the adhesive loses practical adhesive strength.

[0034] Examples of the adhesive include adhesives having a base polymer such as an acrylic polymer, a silicone polymer, a polyester, a polyurethane, a polyamide, a polyether, a fluorine-based polymer, or a rubber-based polymer.

[0035] Examples of adhesives include polyester adhesives, polyurethane adhesives, polyvinyl alcohol adhesives, and epoxy adhesives. If the adhesive is a thermosetting adhesive, it can exhibit peel resistance by being heated and cured (solidified). If the adhesive is a photocurable adhesive such as an ultraviolet curable adhesive, it can exhibit peel resistance by being cured by irradiating it with light such as ultraviolet light. If the adhesive is a moisture curable adhesive, it can be cured by reacting with moisture in the air, and can therefore exhibit peel resistance by being left to stand.

[0036] [Supporting Section] The supporting section 50 has, for example, a rectangular shape in a plan view. The supporting section 50 may have a shape other than a rectangular shape in a plan view. The supporting section 50 can be made of, for example, resin or metal.

[0037] The support portion 50 has an opening 50x and supports the glass layer 10 and the clear coat 20 outside the opening 50x. The opening 50x is, for example, circular in plan view. In the example of FIG. 1 , the opening 50x is a recess that opens on the upper surface side (glass layer 10 side) of the support portion 50. In the example of FIG. 1 , the opening 50x exposes the lower surface of the printed film 30. Note that the cross-sectional view of FIG. 1 shows a cross section cut along a plane that passes through the center of the opening 50x and is perpendicular to the upper surface of the support portion 50.

[0038] The support portion 50 may have a plurality of openings 50x spaced apart from one another. The plurality of openings 50x may be arranged, for example, in a matrix in plan view. A switch 60 may be disposed in each of the openings 50x. Furthermore, one glass layer 10, clear layer 20, and printed film 30 may be disposed so as to cover the plurality of openings 50x. The opening diameter of the opening 50x is preferably 25 mm or greater. An opening diameter of 25 mm or greater makes it easier for the glass layer 10 and the clear layer 20 to deform toward the switch 60.

[0039] [Switch] The switch 60 is disposed on the underside of the printed film 30. The switch 60 is a switch that detects a physical change when pressed. At least a portion of the switch 60 is disposed inside the opening 50x of the support part 50. Operating the switch 60 provides a clicking sensation. In the example of FIG. 1 , the switch 60 is a tactile switch that is disposed so that a movable part faces the underside of the printed film 30.

[0040] The switch 60 is not limited to a tactile switch, and may be any switch that provides a clicking sensation, such as a membrane switch. When the switch 60 is a membrane switch, two sheets are arranged opposite each other to form a space that serves as an opening, and two terminals are arranged facing each other above and below within the opening. In other words, when the switch 60 is a membrane switch, a member that constitutes the switch serves as a support, and part of the member that constitutes the switch (two terminals) is arranged within the opening of the support.

[0041] 1, a gap is provided between the lower surface of the printed film 30 and the movable portion of the switch 60, but this gap need not be provided. It is preferable that the switch device 1 has a gap large enough to prevent the switch 60 from interfering with the flatness of the glass layer 10 and the clear layer 20.

[0042] 3 is a diagram illustrating the operation of the switch device according to the first embodiment. As shown in FIG. 3, in the switch device 1, when the glass layer 10 is pressed in the direction of the arrow, the glass layer 10, the clear layer 20, and the printed film 30 elastically deform to press the movable portion of the switch 60, switching the switch 60 between conductive and non-conductive states. When the pressing of the glass layer 10 is stopped, the glass layer 10, the clear layer 20, the printed film 30, and the switch 60 return to the state shown in FIG. 1.

[0043] A member that can move up and down independently of the glass layer 10 and the clear layer 20 may be sandwiched between the switch 60 and the underside of the printed film 30. This member is supported by the support part 50 in a state that allows it to move up and down, for example, via a spring or the like. When the glass layer 10 is pressed, the glass layer 10, the clear layer 20, and the printed film 30 elastically deform to press this member, thereby switching the switch between conductive and non-conductive states.

[0044] Fig. 4 is a diagram illustrating a reflected image using a switch device according to a reference example. The upper part of Fig. 4 shows a reflected image that occurs when light from a fluorescent lamp located above switch device 1X enters from the glass layer 10 side and is reflected by switch device 1X. The middle part of Fig. 4 is an enlarged view of the vicinity of the fluorescent lamp in the upper part of Fig. 4. The bottom part of Fig. 4 is an image in the middle part of Fig. 4 that has been enhanced.

[0045] The longitudinal ends of the reflected image of the fluorescent lamp should be linear, but in the example of Figure 4, the reflected image is not linear but has irregular bumps and irregularities. Through the study of the inventors, it was found that the magnitude of the unevenness in the reflected image caused by light incident from the glass layer side of the switch device depends on the smoothness of the surface of the transparent adhesive layer that constitutes the clear layer.

[0046] That is, if the surface smoothness of the transparent adhesive layer constituting the clear layer is low, the refractive index varies depending on the location of the transparent adhesive layer, resulting in differences in the intensity of the reflected light returning to the outside of the glass layer. As a result, an uneven reflected image is obtained, as shown in Figure 4. In contrast, if the surface smoothness of the transparent adhesive layer constituting the clear layer is high, the refractive index variation depending on the location of the transparent adhesive layer is reduced, thereby reducing the difference in the intensity of the reflected light returning to the outside of the glass layer. As a result, a reflected image with less unevenness is obtained.

[0047] Since it is difficult to directly measure the surface smoothness of the transparent adhesive layer, the inventors have devised a method of indirectly evaluating the surface smoothness of the transparent adhesive layer by introducing an unevenness value. By introducing an unevenness value into a switch device, it is possible to determine whether or not a reflected image is clearly visible. The unevenness value is the standard deviation of the contrast of the reflected image. Details of the unevenness value will be described later in connection with the examples.

[0048] Examples and Comparative Examples Examples and comparative examples will be specifically described below, but the present invention is not limited to these examples.

[0049] [Example 1] A support having a tactile switch arranged in an opening was prepared, and a printed film, a clear layer, and a glass layer were laminated on the support via a bonding layer to produce a switch device having a structure shown in Figure 1 and measuring 10 cm square in plan view.

[0050] The glass layer used a 100 μm thick glass film (OA-10 manufactured by Nippon Electric Glass Co., Ltd.). The clear layer used a laminate of a 250 μm thick transparent resin layer and a transparent adhesive layer. The transparent resin layer used a 100 μm thick PET film (Cosmoshine A4160 manufactured by Toyobo Co., Ltd.). The transparent adhesive layer used OCA (LUCIACS (registered trademark) CS9866US manufactured by Nitto Denko Corporation) with a thickness of 150 μm and a storage modulus of 0.16 MPa. The bonding layer used an epoxy adhesive.

[0051] (Storage Modulus Measurement) The storage modulus at 25°C was determined by dynamic viscoelasticity measurement. Specifically, a plurality of pressure-sensitive adhesive layers (double-sided pressure-sensitive adhesive sheets in the case of substrate-less double-sided pressure-sensitive adhesive sheets) to be measured were stacked to prepare a pressure-sensitive adhesive layer with a thickness of approximately 2 mm. This pressure-sensitive adhesive layer was punched into a disk shape with a diameter of 7.9 mm, and the sample was sandwiched and fixed between parallel plates. Dynamic viscoelasticity measurement was performed using a viscoelasticity tester (for example, ARES manufactured by TA Instruments or an equivalent) under the following conditions to determine the storage modulus. Measurement mode: shear mode; temperature range: -70°C to 150°C; heating rate: 5°C / min; measurement frequency: 1 Hz.

[0052] (Unevenness Evaluation) The unevenness value of the switch device fabricated in Example 1 was measured.

[0053] First, the fabricated switch device was positioned with the glass layer side facing the light source, so that the angle with respect to the light beam incident on the glass layer from the light source was approximately 45 degrees. A white screen was placed in front of the light beam, and the image reflected by the switch device was projected onto it. The light source used was a "mercury xenon lamp" manufactured by Hamamatsu Photonics K.K. The distance between the top surface of the glass layer of the switch device and the light source, and the distance between the top surface of the glass layer of the switch device and the screen were both approximately 50 cm.

[0054] The unevenness value was determined by turning on the light source, photographing the reflected image reflected by the switch device and projected onto a screen with an EyeScale-4W camera, and reading the photographed image in ISC-S mode. Note that, together with the unevenness value, a photograph of the reflected image that had been subjected to enhancement processing was also obtained.

[0055] [Example 2] A switch device was produced in the same manner as in Example 1, except that an OCA (LUCIACS (registered trademark) CS9868US, manufactured by Nitto Denko Corporation) having a thickness of 200 μm and a storage modulus of 0.16 MPa was used as the transparent adhesive layer, and the same evaluation as in Example 1 was performed.

[0056] [Example 3] A switching device was produced in the same manner as in Example 1, except that a 300 μm laminate was used as the transparent adhesive layer, in which two layers of OCA (LUCIACS (registered trademark) CS9866US, manufactured by Nitto Denko Corporation) having a thickness of 150 μm and a storage modulus of 0.16 MPa were laminated, and evaluations were performed in the same manner as in Example 1.

[0057] [Comparative Example 1] A laminate of a 150 μm thick transparent resin layer and a transparent adhesive layer was used as the clear layer. OCA (LUCIACS (registered trademark) CS9862US, manufactured by Nitto Denko Corporation) with a storage modulus of 0.16 MPa was used as the transparent adhesive layer. Other than these, a switch device was produced in the same manner as in Example 1, and evaluations were performed in the same manner as in Example 1. The thickness of the transparent resin layer was 100 μm, and the thickness of the transparent adhesive layer was 50 μm.

[0058] [Comparative Example 2] A switch device was produced in the same manner as in Comparative Example 1, except that no glass layer was used, and evaluated in the same manner as in Example 1. The thickness of the transparent resin layer was 100 μm, and the thickness of the transparent adhesive layer was 50 μm.

[0059] [Comparative Example 3] A switch device was produced in the same manner as in Example 1, except that a double-sided tape (TR-5302F, manufactured by Nitto Denko Corporation) having a thickness of 200 μm and a storage modulus of 0.44 MPa was used as the transparent adhesive layer, and the same evaluation as in Example 1 was performed.

[0060] Comparative Example 4 A switch device was produced in the same manner as in Example 1, except that a double-sided tape (EW-514, manufactured by Nitto Denko Corporation) having a thickness of 140 μm and a storage modulus of 0.068 MPa was used as the transparent adhesive layer, and the same evaluation as in Example 1 was performed.

[0061] [Evaluation Results] The results of the Examples and Comparative Examples are summarized in Figure 5. The photograph in Figure 5 is a photograph in which an enhancement process has been applied to the photographed image.

[0062] As shown in Figure 5, the unevenness value in Example 1 was 4. In Example 1, as is clear from the photographed image subjected to enhancement processing, a good reflected image with little variation in contrast was obtained. Furthermore, by changing the thickness as in Examples 2 and 3, a good reflected image with even less variation in contrast was obtained. In this state, it can be said that the switch device has a high quality texture.

[0063] In contrast, the unevenness value in Comparative Example 1 was 7.4. In Comparative Example 1, as can be seen from the photographed image subjected to enhancement processing, the contrast variation was greater than in Example 1, and it cannot be said to be a good reflected image. Furthermore, in Comparative Example 2 without a glass layer, the unevenness value was 12.6. In Comparative Example 2, as can be seen from the photographed image subjected to enhancement processing, the contrast variation was even greater than in Comparative Example 1. Furthermore, when the storage modulus was increased as in Comparative Example 3, the contrast variation became even greater, and similarly, when the thickness of the transparent adhesive layer was less than 150 μm as in Comparative Example 4, a good reflected image was not obtained.

[0064] In this way, the unevenness value can be used to evaluate the variation in contrast of the reflected image of the switch device. Further detailed studies by the inventors have confirmed that a good reflected image with small variation in contrast can be obtained if the unevenness value is 5 or less.

[0065] The unevenness value can be reduced by adjusting the thickness of the transparent adhesive layer constituting the clear layer to increase the smoothness. In addition to this, or separately, the unevenness value can also be reduced by adjusting the components of the transparent adhesive layer constituting the clear layer to increase the smoothness. In other words, even if the thickness of the transparent adhesive layer is the same, by adjusting the components of the transparent adhesive layer, the unevenness value can be reduced even if the smoothness is increased.

[0066] Although the preferred embodiments have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims.

[0067] In addition to the above embodiments, the following supplementary notes are further disclosed. (Supplementary Note 1) A switch device comprising: a glass layer; a clear layer disposed on the underside of the glass layer; and a switch disposed on the underside of the clear layer, wherein the thickness of the glass layer is 20 μm or more and 150 μm or less; a reflection image generated by light incident from the glass layer side has an unevenness value of 5 or less; and when the glass layer is pressed, the glass layer and the clear layer elastically deform, switching the switch between conductive and non-conductive states. (Supplementary Note 2) The switch device according to Supplementary Note 1, wherein the unevenness value of the reflection image is 4 or less. (Supplementary Note 3) The switch device according to Supplementary Note 1 or 2, wherein the clear layer includes a transparent adhesive layer. (Supplementary Note 4) The switch device according to Supplementary Note 3, wherein the storage elastic modulus at 25°C of the transparent adhesive layer is 0.1 MPa or more and 0.4 MPa or less. (Supplementary Note 5) The switch device according to Supplementary Note 3, wherein the clear layer has a laminated structure of a transparent resin layer and a transparent adhesive layer, and the transparent resin layer is disposed on the glass layer side. (Supplementary Note 6) The switch device according to Supplementary Note 5, wherein the transparent adhesive layer is thicker than the transparent resin layer. (Supplementary Note 7) The switch device according to Supplementary Note 5, wherein the transparent resin layer has a thickness of 50 μm or more and 150 μm or less. (Supplementary Note 8) The switch device according to any one of Supplements 1 to 7, wherein the glass layer has a thickness of 50 μm or more and 100 μm or less.

[0068] This international application claims priority based on Japanese Patent Application No. 2024-055968, filed on March 29, 2024, the entire contents of which are incorporated herein by reference.

[0069] REFERENCE SIGNS LIST 1 Switch device 10 Glass layer 10a Upper surface 10b Lower surface 20 Clear layer 30 Printed film 40 Bonding layer 50 Support portion 50x Opening 60 Switch

Claims

1. A switch device comprising: a glass layer; a clear layer disposed on the underside of said glass layer; and a switch disposed on the underside of said clear layer, wherein the thickness of said glass layer is 20 μm or more and 150 μm or less; the unevenness value of a reflected image caused by light incident from said glass layer side is 5 or less; and when said glass layer is pressed, said glass layer and said clear layer elastically deform, switching said switch between conductive and non-conductive states.

2. The switch device according to claim 1, wherein the unevenness index of the reflected image is 4 or less.

3. The switch device according to claim 1, wherein the clear layer includes a transparent adhesive layer.

4. The switch device according to claim 3, wherein the storage modulus of the transparent adhesive layer at 25°C is 0.1 MPa or more and 0.4 MPa or less.

5. The switch device according to claim 3, wherein the clear layer has a laminated structure of a transparent resin layer and a transparent adhesive layer, and the transparent resin layer is disposed on the glass layer side.

6. The switch device according to claim 5, wherein the transparent adhesive layer is thicker than the transparent resin layer.

7. The switch device according to claim 5, wherein the thickness of the transparent resin layer is 50 μm or more and 150 μm or less.

8. A switch device according to any one of claims 1 to 7, wherein the thickness of the glass layer is 50 µm or more and 100 µm or less.

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