HK1061605B - Push-button switch member and method of manufacturing same - Google Patents

Description

Member for push switch and method for manufacturing the same

Technical Field

The present invention relates to a member for a push switch, which has a display portion and can display a switch state of an input device provided in a mobile terminal such as a mobile phone or a PDA (personal digital assistant), a car audio, a car computer, an audio, a measuring instrument, a personal computer, or the like, and more particularly, to a member for a light-emitting push switch, which can illuminate the display portion in a dark place, and a method for manufacturing the member.

Background

In general, a member for a key switch used in such an input device needs to have a so-called character lighting function, i.e., a lighting function of lighting a display unit for displaying the key switch function, when used at night.

As shown in fig. 18 and 19, taking a key switch 30 used in an input device such as a mobile phone as an example, a cover base 32 integrally formed with a plurality of key tops 31 constituting operation keys and a circuit board 33 are mounted in an input device frame in a state of facing each other, so that the switch function of the key switch 30 is realized. In order to understand the function of the key switch 30 even in a dark place, a display unit 34 capable of expressing the function of each key by various characters, symbols, patterns, or the like is provided on the top surface or the back surface of the key top 31 constituting each operation key, and the content displayed on the display unit 34 is made visible through the top surface from the inside of the key top 31 by emitting direct light from a light source such as an LED (light emitting diode) 35 or a bulb 36 provided on the circuit board 33 or by reflecting the direct light by surrounding members. Thus, the mobile phone or the like can be used without any trouble even at night.

As shown in fig. 20 and 21, when it is required to obtain a relatively uniform illumination, attempts have been made to enlarge the light emitting area by inserting a thin plate-like light guide member 37 between the LED35 and the key top 31, or by using a surface-emitting EL (electroluminescence) sheet (エレクトロルミネセンスシ - ト)38 as a light source.

However, since the light source such as the LED35, the bulb 36, and the EL sheet 38, and the light guide member 37 for guiding the direct light emitted from the light source are placed at a position apart from the key top 31 so as not to hinder the contact operation between the contact 39 on the circuit board 33 and the key top 31, the light source 35, 36, and 38, and the light guide member 37 are separated from the display unit 34, and when the number of the LEDs 35 and the bulb 36 is increased, the light guide member 37 is increased, or the EL sheet 38 is used at high cost, the difficulty of installation is increased due to the increase in the number of the members, and sufficient brightness for viewing the display unit cannot be provided in a dark place, which is not practical.

In particular, in a mobile phone driven by a battery, it is desired to save power and provide sufficient light using a small number of light sources, and there is a contradiction that it is not desired to improve the visibility of the display portion 34 by using only a part of light emitted from a light source as in the above-described conventional method, and the visibility cannot be improved even when a large amount of power is consumed.

Moreover, between the key tops 31 and the contact points 39 of the circuit board 33 corresponding thereto, the thickness of the key switch 30 cannot be thinned in order to dispose the light sources 35, 36, 38 and the light guide member 37, thereby limiting the reduction in thickness of the input device and the machine itself and resulting in an increase in weight.

Therefore, in order to solve the above problems, as described in the inventions disclosed in japanese patent laid-open gazette nos. hei 11-232954 and 285760 of 2000, a lot of work has been done to prevent light from being diffused and lost due to obstacles by providing a surface light emitter on the key top surface and mounting a light source near the display unit.

In such a surface emitting device, the transparent conductive layer is formed by printing a ceramic layer formed by a particle beam processing method using tin oxide, indium tin oxide, antimony tin oxide, or the like, or a transparent conductive ink obtained by dispersing and mixing ceramic powder and a transparent insulating resin, on a transparent insulating film through a screen (スクリ - ン).

However, when the transparent conductive layer is formed as a ceramic layer by a particle beam processing method using tin oxide, the ceramic layer itself is brittle and hardly expands or contracts, and although the transparent insulating film as a base material can be formed into a desired shape of the key top, the transparent conductive layer does not change, and a strong adverse resistance is generated. In addition, although the transparent conductive layer printed by the transparent conductive ink in which the ceramic powder is dispersed and mixed in the transparent insulating resin can secure the conductivity by the linkage of the powder, the resistance is not lowered even when the content of the ceramic powder is increased, the uniform dispersion operation of the powder is relatively difficult, and when the transparent insulating film as the base is formed into a desired key top shape, the linkage portion of the ceramic powder of the transparent conductive layer is easily broken, and the resistance value is increased, resulting in insufficient brightness.

Disclosure of Invention

In order to solve the above-mentioned problems of the conventional key switch member for illuminating the display unit, it is an object of the present invention to provide a high-definition, thin and light key switch member which can illuminate the display unit without wasting light energy, and which can realize illumination of the display unit with high luminous efficiency by suppressing power consumption without lowering luminance.

In order to achieve the above object, the invention according to claim 1 provides a member for a push switch, comprising a push top portion for pressing a movable contact disposed to face a fixed contact on a circuit board in a direction in which the movable contact can come into contact with the fixed contact; the outer cover substrate and in order to install the above-mentioned key top in the specific position on the above-mentioned circuit board, still have simultaneously with can be in the integrative surface illuminant who sets up of display part of the switch function of the above-mentioned key top display, characterized in that: the surface light-emitting body has a light-emitting layer provided between a base electrode and a transparent electrode facing the base electrode, and the transparent electrode is made of the transparent conductive polymer and is provided so as to be connected to the display section.

Thus, the display part can emit light, so that the visibility of the key top is greatly improved.

Meanwhile, since the light-emitting layer of the surface light-emitting body is used only at the key top, the manufacturing cost can be reduced and the power consumption for illumination can be reduced. Further, since the light source and the light guide member are not provided between the key tops and the contacts provided on the circuit board corresponding thereto, it is possible to provide a thin member for a push switch. Therefore, the thickness of the input device and the device itself to which the member for a push switch is applied can be reduced.

The invention of claim 2 is characterized in that: in the invention according to claim 1, the transparent electrode has a surface resistance of 10 Ω/□ or more and a light transmittance of 90% or less.

Thus, the transparency and the ductility are ensured, and the internal power consumption is reduced.

The invention 3 is characterized in that, in the invention according to claim 1 or 2, the transparent electrode contains conductive fibers having a wire diameter of 0.5 μm and an aspect ratio of 20 or more.

Thus, since transparency and conductivity can be maintained even when drawing is caused by deep drawing, reliability of the switching member can be further improved in addition to the effects of claims 1 to 2.

The invention of claim 4 is characterized in that the transparent electrode is colored in addition to the inventions of claims 1 to 3.

In this way, since the number of members constituting the display portion can be reduced, the manufacturing cost can be further reduced.

The invention of claim 5 is characterized in that, in the inventions of claims 1 to 4, the transparent conductive polymer is composed of any one derivative of polypyrrole (ポリピロ - ル), polythiophene (ポリチオフエン), and polyaniline (ポリアニリン).

The transparent conductive polymer has high stability to oxygen and humidity and good transparency and conductivity, so that the visibility of the top of the key and the reliability of the key function are further improved.

The invention of claim 6 is characterized in that: in the invention according to any one of claims 1 to 5, the base electrode and the transparent electrode are connected to a conductor having extensibility, and at least an extending portion of the conductor, which is subjected to a tensile force during molding, is covered with an insulating film having extensibility.

Thus, the insulating film can restrict the movement of the conductive material connected to the base electrode, suppress the increase in the resistance value of the base electrode, and obtain a display portion which emits light uniformly. Further, since the small light-emitting layer is provided near the display unit, not only is power consumption low, but also good visibility can be obtained in design and no other extra parts are required, so that a light and economical member for a push switch can be provided.

The 7 th invention is characterized in that, in the invention according to the 6 th invention, the conductor connected to the base electrode and the conductor connected to the transparent electrode are arranged so as to overlap each other in a plan view.

Thus, when the transparent electrode is used as a molded product or a molded product, the base electrode and the transparent electrode are not damaged or broken in contact with each other, and thus stable illumination can be obtained.

The invention according to claim 8 is the one according to claim 6 or 7, wherein the storage elastic modulus of the insulating film material at the molding temperature is larger than the storage elastic modulus of the conductor connected to the base electrode and the conductor connected to the transparent electrode at the molding temperature.

Thus, the formability of the key top is improved.

The 9 th invention is characterized in that, in any one of the 6 th to 8 th inventions, the base electrode and the conductor connected to the base electrode are formed of a conductive layer containing an organic polymer and a conductive filler (フイラ |), and the length of at least one side of the conductive filler is 1/3 or less of the thickness of the conductive layer.

In this way, since the intertwined state of the filler can be maintained even after molding, the conductive performance can be relatively reliably ensured.

The invention according to claim 10 is characterized in that, in addition to the invention according to claim 9, the conductive polymer layer is added to the conductive layer.

Therefore, the conductivity can be better ensured.

The 11 th aspect of the present invention is the 9 th or 10 th aspect of the present invention, wherein the conductive filler is a fibrous material having a wire diameter of 1 μm or less.

Since the conductive filler is easily oriented during molding, the necessary conductivity can be maintained even if the conductive filler is excessively stretched by more than 200%.

The 12 th invention is characterized in that, in the invention of the 6 th to 11 th, the base electrode and the conductor connected to the base electrode are made of a conductive polymer.

Thus, excessive increase in resistance due to stretching is less likely to occur, and the yield of molding processing is more likely to be stabilized.

The 13 th invention is characterized in that, in any one of the inventions 1 to 12, the key top includes a key top main body having a desired key top shape formed on a back surface of the base electrode, and a pressing portion for allowing the movable contact to contact the fixed contact is further provided inside the key top main body.

Thus, the movable contact can be reliably contacted with the fixed contact by the pressing part, and the reliability of the switch can be improved.

The 14 th invention is characterized in that, in any one of the 1 st to 12 th inventions, the key top has a transparent 1 st resin molded body formed by a transparent insulating film into a desired key top shape on a surface of the transparent electrode; the back surface of the base electrode is provided with a No. 2 resin molded body which is provided with a pressing part capable of making the movable contact and the fixed contact.

Thus, the movable contact can be reliably contacted with the fixed contact by the pressing part, and the reliability of the switch can be improved.

The 15 th invention is characterized in that, in addition to any one of the inventions 1 to 12, a plurality of switch circuits each including a plurality of key tops and base electrodes and transparent electrodes corresponding to the plurality of key tops are integrally formed with the surface base material.

Thus, since the plurality of key tops can be uniformly and brightly illuminated, it is suitable for use in electric and electronic appliances such as mobile phones, etc., which must have a plurality of key tops, while remarkably improving design and usability.

The 16 th aspect of the present invention is the method for manufacturing a member for a push switch according to any one of the 1 st to 15 th aspects of the present invention, wherein when the member having the transparent electrode formed thereon is subjected to a deep drawing process on one surface of a transparent insulating film to form a desired shape of the key top, a conductive polymer having ductility is used at least on the transparent electrode of the extending portion on which a tensile force acts during the deep drawing process.

Thus, since the poor conduction caused by the molding process is eliminated, the problem caused by the poor conduction of the side surface of the key top is not caused, and the manufacturing efficiency is improved.

The 17 th invention is characterized in that, in the 16 th invention, at least before the deep drawing process, the extension portion of the transparent electrode is formed to have an appropriate thickness.

Thus, the conductivity of the extending part of the transparent electrode formed by molding is maintained, and poor conductivity caused by the bent part of the transparent electrode is eliminated, thereby improving the manufacturing efficiency.

The 18 th invention is characterized in that the method for manufacturing a member for a push switch according to any one of the 6 th to 15 th inventions, comprising a step of manufacturing a printed film before deep drawing, wherein a transparent electrode is formed at a position corresponding to a key top on a side of a transparent insulating film covering an outer surface of the key top, a light-emitting layer is formed on the transparent electrode, a base electrode is formed on the light-emitting layer, a conductor having ductility and connected to the base electrode and the transparent electrode is formed, and a molding step of forming a desired key top shape by subjecting the printed film to deep drawing; the extension part as a part of the conductor to which a tensile force acts during the drawing is covered with an insulating film.

Thus, the insulating film can restrict the movement of the conductive material connected to the base electrode, suppress the increase in the resistance value of the base electrode, and obtain a display portion which emits light uniformly. Similarly, since the small light-emitting layer is provided in the vicinity of the display portion, it is possible to provide a light-weight and economical member for a push switch which is excellent in visibility and does not require any extra member, while reducing power consumption.

Brief description of the drawings

Fig. 1 is a partial sectional view showing a member for a push switch according to embodiment 1 of the present invention.

Fig. 2 is a partial sectional view showing a member display section for a push switch according to the 1 st aspect (corresponding to embodiment 1) of the present invention.

Fig. 3 is a partial sectional view of the 2 nd form showing the same display section.

Fig. 4 is a partial sectional view showing the same display section in the 3 rd form.

Fig. 5 is a partial sectional view of the 4 th form showing the same display section.

Fig. 6 is a partial sectional view of the 5 th form showing the same display section.

Fig. 7 is a partial sectional view of the 6 th form showing the same display section.

Fig. 8 is a partial sectional view of the 7 th form showing the same display section.

Fig. 9 is a partial sectional view of the 8 th form showing the same display section.

Fig. 10 is a partial sectional view showing the same display section in the 9 th form.

Fig. 11 is a partial sectional view showing the 10 th form of the same display section.

Fig. 12 is an enlarged cross-sectional view of the key switch member according to embodiment 2 of the present invention, showing a main part thereof, and showing the structure shown in fig. 3.

Fig. 13 is a plan view showing the same push switch member base electrode and a conductor pattern connected thereto.

Fig. 14 is a plan view showing transparent electrodes of the same member for push switches and conductor patterns connected thereto.

Fig. 15 is a plan view showing a state in which a transparent electrode and a conductor pattern connected thereto are superimposed on a base electrode and a conductor pattern connected thereto of the same member for push switch.

Fig. 16 is an enlarged cross-sectional view showing a structure of a base electrode for the display portion shown in fig. 11 and provided.

Fig. 17 is a partial sectional view showing a member for a push switch according to embodiment 3 of the present invention.

Fig. 18 is a partial sectional view showing a conventional member for a push switch using an LED as a light source.

Fig. 19 is a partial sectional view showing a member for a push switch using a conventional bulb as a light source.

Fig. 20 is a partial sectional view showing a conventional member for a push switch using a light guide member.

Fig. 21 is a partial cross-sectional view showing a member for a push switch using a conventional EL sheet as a light source.

Detailed Description

The embodiments of the present invention will be described in detail below with reference to the drawings.

Embodiment mode 1

Fig. 1 is a partial sectional view showing a member for a push switch according to embodiment 1 of the present invention.

In a member 1 for a push switch according to embodiment 1 shown in fig. 1, a display part 2 showing a switching function of characters, symbols, and patterns is provided on a surface side of a key top 3, and a surface light emitting body 4 which emits light by itself is used as the display part 2.

In the member 1 for a push switch according to embodiment 1, the movable contact 7 is provided so as to face the fixed contact 6 on the circuit board 5. Specifically, a movable contact 7 is provided at the tip of a pressing portion 8 provided at the center of the back surface of the key top 3, and the movable contact 7 can be brought into contact with the fixed contact 6 by pressing the key top 3 toward the circuit board.

Further, a cover base material (not shown) made of an elastic material such as silicone rubber is formed on a plurality of key tops 3 provided at predetermined positions between the key switch member 1 and the circuit board 5 at the outer periphery of the key tops 3, and when the key tops 3 are pressed, a part of the cover base material is elastically deformed in the direction of the circuit board 5, and when the hand is separated from the key tops 3, the key tops 3 are restored to the original positions by the elastic restoring force of the cover base material.

The material of the key top main body 16 for determining the actual shape of the key top 3 is selected from hard and soft resins, elastomers, and the like. The resin composition can be thermoplastic and thermosetting, and is not limited to the form of raw materials such as film, pellet (ペレツト) and liquid, but the liquid thermosetting resin can be injected more easily.

The transparent insulating film 9 is covered on the outer surface except the back surface of the key top 3, and a transparent electrode 10 constituting an electrode on the side of the surface light emitter 4 is provided on the inner side of the transparent insulating film 9 from the side surface of the key top 3 to the upper surface of the key top 3. Further, opaque colored layers 11 having light-shielding properties and insulating properties are provided on the back surface of the transparent electrode 10 and in the transparent insulating film 9 where the transparent electrode 10 is not provided. Further, a stamp portion (ヌキガタブ)12 corresponding to the form of characters, symbols, patterns, and the like of the display portion 2 is provided on the opaque colored layer 11. The opaque coloring layer 11 is provided on the back surface thereof with a light-emitting layer 13 slightly smaller than the upper surface of the key top 3 including the stamp portion 12. The die part 12 is surrounded by the light-emitting layer 13 in this way, a pattern part composed of characters, symbols, patterns, and the like is formed, and the design of the display part 2 is completed by this pattern part and a cover layer formed by the opaque colored layer 11 around the die part 12 (デザイン). Thus, the base electrode 14 on which the other electrode is formed is provided inside the light-emitting layer 13. The transparent insulating film 9 on the outer surface of the key top 3 may be formed of polyvinyl alcohol, polyethylene terephthalate, polyacrylate, polycarbonate, polystyrene, polyfluoroethylene propylene, polychlorotrifluoroethylene, polyvinylidene, polyimide, polyamide-imide, polyether sulfone, polysulfone, polyphenylene sulfide, polyamide, polyallylate, or a thermoplastic elastomer such as styrene, polyester, polyamide, or the like, or a modified product thereof such as a polymer or a mixture thereof, and may be formed of a multilayer product obtained by laminating a plurality of films (ラミネ - シヨン), or the like. Here, the resin which easily forms the shape of the key top has a softening point of 50 to 200 ℃, preferably 100 ℃ to 150 ℃ and has a small air permeability. After the molding, a gas barrier (ガスバリア) layer is formed on the outer layer by a vapor deposition method of an inorganic oxide such as silicon oxide or aluminum oxide, a sol-gel (ゾルゲル) method, or the like, to protect the light-emitting layer 13, whereby the service life is expected to be extended.

As the conductive polymer used for the transparent electrode 10, it is recommended to use polyacetylene, polyparaphenylene, polypyrrole, polythiophene, polyaniline, polyphenylene vinylene, polyselenophenol, polycyclopentarylene, polypyrene, polycarbazole, polypyridazine, polynaphthalene (ポリナフチレン), polyfluorene, and a covalently conductive polymer such as polyethylene dioxythiophene, polyethylene vinylene (ポリチエニレンビニレン), poly (3 methylthiophene), poly (3, 4-dimethylthiophene), poly (3-thiophene-. beta. -ethanesulfonate), polymethylpyrrole, poly (3 hexylpyrrole), poly (3-methyl-4-pyrrolecarbonate), polycyanophenylethene, polydimethoxyphenylenevinylene derivatives, or polyisoprene-modified compounds, to which substituents such as alkyl groups and alkoxy groups have been added.

Among them, polypyrrole, polythiophene and polyaniline, which have high stability against oxygen and humidity and are transparent and have good conductivity, are preferably used, although they may also have the influence of the dopant (ド - パント). In the case of using an organic EL, it is preferable to use a derivative of polyaniline or polythiophene having a high work function as an anode.

The conductive polymer has good rigidity and poor adhesiveness because its backbone is a conjugated double bond. Therefore, in order to provide good adhesion to the substrate material, it is preferable to add a highly polar anchor primer layer (アンカ - コ - ト), such as polyurethane, amide, polyacrylamide, and polymers having an amino group, hydroxyl group, nitrile group, carbonyl group, or cyano group in a branched chain.

In addition, the conductive polymer cannot obtain a sufficient resistance value, and it is necessary to perform a doping treatment such as a halide of iodine element, bromine element, or the like, PF, which is used as an acceptor (アクセプタ one)₅、AsF₅、BF₃Etc. Lewis acids (ルイス acids), HF, HCl, H₂SO₄And protonic acids (プロトンサン) such as p-xylylene disulfonic acid, and organic acids such as p-dimethoxyethyltoluene disulfonic acid, FeCl₃、TiCl₄Transition metal compounds such as tetracyanodimethane, tetracyanotetrazene, trichloroethylene glycol and the like; or alkali metals such as Li, Na, and K, and alkaline earth metals such as Ca, Sr, and Ba, which are used as donors.

Because of the increased stability to temperature and humidity, care should be taken to avoid exposure to electrolyte anions, cations, and dative bonds and copolymerization with conductive polymers are effective means of immobilizing these desizing pastes (ダツド - プ). In particular, the dopant is introduced into a dendrimer (デンドリマ -one) synthesized by sequentially binding from a central core molecule, an oligomer such as polystyrene, polymethyl methacrylate, or polyurethane, a polymer, or フラ - レン molecules, using an AB2 type monomer as a starting material, and is supported easily as a functional group, thereby improving the sealing property of the transparent insulating film 9. In addition, such a carrier becomes a multifunctional dopant at the center, and is very effective for smoothly reducing the resistance because it can link conductive polymer molecules with respect to conductivity. The conductive polymer is preferably collected in the molded article in a sealed state because the influence of the degummed paste is small. Further, stretching the conductive polymer to reduce the conductivity is effective to stretch the conductive polymer to reduce the distance between the molecules of the conductive polymer, and therefore, stretching during molding can be used.

In the deep drawing, since the side surface portion (extending portion) of the key top 3 is stretched by a tensile force, it is necessary to use appropriate materials for the transparent insulating film 9 and the transparent electrode 10, and a material that is not easily broken and is not easily increased in resistance value is selected. The conductive polymer is a material used herein. The physical thickness of the material, which does not change the intrinsic resistance value of the conductive polymer, is reduced by molding, and the resistance value is increased by stretching. Therefore, a thick conductive polymer is formed around the pattern portion (extending portion) of the display portion 2 having good ductility, and an increase in the absolute value of the resistance value can be suppressed. When the base of the display unit 2 or the side surface of the key top 3 is opaque, compensation can be made by conductive ink described later.

If the elongation exceeds the limit of 100%, the resistance may be increased. In this case, the conductivity can be maintained by mixing fine conductive fibers having a wire diameter of 0.5 μm or less into the conductive polymer. If the fiber diameter exceeds 0.5 μm, it cannot be transparent and the fibers are hard to form. The aspect ratio is 10 or more or 20 or more, preferably 50 or more. From the viewpoint of printability, the length is preferably 0.1 mm or less.

Further, when the conductive polymer is over-stretched by more than 200%, if a fine conductive fiber having a wire diameter of 1 μm or less is mixed in the conductive polymer, the alignment conductivity can be maintained in the direction of the conductive fiber during molding.

The conductive fiber is a split product of carbon fiber such as polyacrylonitrile, or may be a product obtained by coating ceramic whisker such as zinc oxide or potassium titanate with carbon or silver, but is more preferably a flexible material, and may be a synthetic fiber of acryl, rayon, polyester or phenol after silver plating, a single-walled nanotube, a multi-walled nanotube or the like, and the diameter of the nanotube is preferably 0.2 μm or less. The amount blended is from 0.1 to 20 wt% depending on the desired resistance value. Of course, the finer the diameter and the smaller the blending amount, the better the transparency.

The conductive polymer can be obtained by a chemical polymerization method in which a monomer of a precursor thereof is polymerized with an oxidizing agent or a catalyst, a method in which an intermediate composed of a non-covalent polymer is heat-treated, or an electrolytic polymerization method in which an aromatic compound is electrochemically oxidized or reductively polymerized as a monomer, or the like, but is not limited thereto.

The transparent insulating film 9 may be formed by a common printing coating method, by depositing a monomer substance of a conductive polymer thereon, or by dissolving the conductive polymer in water or a solvent, or by dispersing the conductive polymer in an emulsion. The film thickness is approximately 0.1 to 25 μm. In general, the relationship between the film thickness of the conductive polymer and the resistance is non-ohmic, that is, the light transmittance is deteriorated only by making the thickness thicker without decreasing the resistance. Therefore, the necessary thickness should be determined in advance.

The surface resistance of the transparent electrode 10 is 10 Ω/□ or more, preferably 100 Ω/□ or more, and the light transmittance is desirably 90% or less, preferably 80% or less. The surface resistance and the light transmittance are inversely related, and if the surface resistance is less than 10. omega./□, the dopant amount increases, the coloring becomes strong and the desired color cannot be obtained, and the conductive polymer also becomes hardened and cannot exhibit sufficient ductility. Although the higher the light transmittance, the better, the surface resistance increases excessively when it exceeds 90%, thereby causing an increase in power consumption.

The light-emitting structure of the light-emitting layer 13 of the surface light-emitting body 4 is preferably a structure that emits light uniformly over the display section 2 by using a photoelectric conversion device, and in consideration of the problem of the composite structure with a resin molded body, an organic inorganic EL, an organic EL, or an LEC (electrochemical light-emitting element) may be used, and the organic EL, or the LEC may be a device that emits visible light directly or a device that emits ultraviolet light other than visible light and converts the ultraviolet light into visible light. In which one of them must have an electrode for supplying power, in embodiment 1, one side electrode is a transparent electrode 10, and the other side is a base electrode 14.

The inorganic EL is formed by providing a light-emitting layer 13 having a thickness of about 5 to 50 μm between two electrodes facing each other, at least one side of which is transparent, and applying an alternating current of 20 to 100V and 50 to 400Hz to emit light. When a dc power supply of a portable device is used, it is necessary to boost the voltage by a transformer and convert the voltage into ac.

The light-emitting layer 13 is prepared by dispersing inorganic phosphor powder such as zinc sulfide in a ferroelectric organic binder such as cyanoethyl cellulose, cyanoethyl sucrose, cyanoethyl プルラン, etc., and wet processing the resultant solution of acetonitrile, dimethylformamide, dimethylacetamide, etc. In particular, a phosphor can be doped with a metal such as copper or iron to obtain various colors. Furthermore, microencapsulation (マイクロカプセル) of the phosphor with ceramic by plasma polymerization, sol-gel method, or other known methods can improve the stability of moisture resistance, sealing properties with the substrate, and the like. In addition, a strong dielectric such as barium titanate or potassium titanate may be mixed into the binder to synthesize an excitation reflection layer or the like, thereby improving the electric field efficiency.

In order to achieve good adhesion to the transparent electrode 10 made of a conductive polymer having low adhesion, it is preferable to use the same material as the anchor primer layer.

As the light-emitting material of the light-emitting layer 13, a toluene solution or the like in which an electron-transporting pigment such as an aluminum trihydroxide complex is mixed with an ink or a hole-transporting binder such as polyvinylcarbazole; the ink is prepared by dissolving phosphor powder obtained by doping zinc sulfide with copper or the like in a binder of a strong dielectric substance such as cyanoethyl cellulose, cyanoethyl sucrose, cyanoethyl プルラン, or dissolving ceramic powder of a strong dielectric substance such as barium titanate in a polar solution such as acetonitrile.

The inorganic EL sheet has been conventionally used as a planar light source, but in the present invention, since it is used only in the display section 2, it is sufficient that the area thereof is only 1/5-1/100 of the conventionally used backlight, and power consumption can be reduced in proportion.

Organic EL is classified into low-molecular type and high-molecular type depending on the light-emitting material used. The present invention is explained in the scope of the present invention, wherein a polymer type having a large film thickness is easy to process, and wherein a 5-20V direct current is applied to functional layers such as an electron injection layer, a hole injection layer, a transport layer, and the like, which are provided as necessary, or a light-emitting layer 13 having a thickness of about 0.1-0.15 μm, between two facing electrodes having at least one side transparent, and sandwiching the light-emitting layer 13. The light-emitting layer 13 may have a soluble pi covalent polymer of a polyparaphenylene vinylene derivative, a polythiophene derivative, a thiocyclopentadiene polyethylene derivative, a polyfluorenone, a polyacetylene derivative, a polyvinylcarbazole derivative, or the like (CMC published as "organic EL material and display"). These solutions can be set by spin coating (スピンコ - ト), inkjet printing, or the like, and the color is determined by the energy gap inherent in the substance, and the larger the energy gap, the closer to the short wavelength side. The light-emitting layer 13 and the upper and lower electrode layers depend on the balance between electron and hole injection. In the case of the polymer type, the structure of the dye dispersion type is simple. A polyvinyl carbazole derivative or a polystyrene compound is mixed with an electron-transporting substance such as an aluminum trihydroxide complex or a hole-transporting substance such as an oxadiazole (オキサジアゾ - ル) derivative, and a mixed layer in which a laser dye such as a coumarin derivative, quinacridone (キナクドリン) or rubrene is mixed as a dopant is sandwiched between electrodes. Further, polymethylenephenylsilane or the like of the σ covalent polymer has an emission peak in a near ultraviolet region, and can emit visible light by mixing laser pigments such as butylbenzoxazolylthiophenol, benzopyrene derivatives, and the like.

The LEC has a structure in which a light-emitting layer 13 is sandwiched between two opposed electrodes, at least one of which is transparent, the light-emitting layer 13 having a thickness of only about 15 μm, and the light-emitting layer 13 is a mixture of the same covalent polymer as the organic EL, a polymer such as ethylene oxide or phosphate, or an oligomer electrolyte, and a metal salt such as lithium trifluoromethanesulfonate. When a direct current of 3 to 5V is applied, the cation and anion pairs of the salt electrochemically mix with the covalent polymer to generate a P-type or N-type semiconductor in an electrochemically balanced manner, and electrons or holes can be efficiently supplied to the covalent polymer, thereby emitting light as in the case of organic EL (WO 96/00968).

Among the above 3 types of surface emitting bodies 4, inorganic EL is recommended because the film thickness can be easily controlled and the stability to the environment is good, and LEC has a simple structure, so that there is no limitation on the electrode material and the film thickness can be easily controlled and low power consumption can be achieved.

The base electrode 14 facing the transparent electrode can be formed by photopolymerization, radiation polymerization, plasma polymerization, or electrolytic polymerization using a metal or an alloy such as gold, silver, copper, nickel, aluminum, magnesium, calcium, lithium, palladium, or platinum, or a conductive ceramic such as tungsten carbide, silicon carbide, tin oxide, or indium oxide, or fullerene. When the light-emitting layer 13 is an organic EL, a material having a large work function difference between the transparent electrode 10 and the material is selected. In addition to the fine particles, the conductive particles may be formed using a conductive ink in which a conductive filler such as laccai carbon or graphite is mixed in an insulating resin solution such as an epoxy resin, a urethane resin, or a silicone resin.

Similarly to the transparent electrode 10, in order to control the resistance change by stretching, the conductive filler such as the conductive ceramic fine particles, lac carbon, and graphite is mixed with an organic polymer such as a low-covalent thermosetting resin such as an epoxy resin, a urethane resin, and a silicone resin, or a high-molecular thermoplastic resin such as an amide, a polyester, a polypropylene, a chlorinated polyolefin, a non-sulfur synthetic rubber, and a thermoplastic rubber. In addition, the conductive polymer may be used instead of the organic polymer to form the base electrode 14.

When a conductive polymer is used, the adhesive itself is conductive, and therefore, even when the connection of the conductive filler is broken, conduction can be maintained, and therefore, it is recommended to use the conductive polymer. Further, when the conductive fiber or the bendable carbon nanotube is mixed, the resistance is reduced due to the bypass effect, and thus the conduction can be well maintained.

A method for manufacturing the member 1 for a push switch in embodiment 1 will be described below.

A flat transparent insulating film 9 is placed on the bottom, a band-shaped transparent electrode 10 having a width substantially equal to the width of the upper surface of a key top 3 is formed at the position of the key top 3 of the transparent insulating film 9, and a sufficiently large opaque coloring layer 11 covering all the outer surfaces except the back surface of the key top 3 is formed by performing a back printing (ネガ) with an opaque coloring ink having a light-shielding property and an insulating property from above the transparent electrode 10 centering on the position of the upper surface of the key top. At this time, the stamp part 12 is formed in the shape of the pattern part of the display part 2 capable of displaying the key function at the position of the upper surface of the key top 3 of the opaque coloring layer 11.

Next, on the opaque colored layer 11, a light emitting material is printed in a region slightly smaller than the upper surface of the key top 3 including the stamp portion 12 to form a light emitting layer 13. Thus, the die portion 12 is filled with the light-emitting layer 13. Further, a base electrode 14 having a size similar to that of the light-emitting layer 13 is formed on the light-emitting layer, and the light-emitting layer 13 remains in the die portion 12 of the opaque colored layer 11, whereby a printed film (not shown) before deep drawing is completed.

As the light-emitting material of the light-emitting layer 13, a toluene solution in which an electron-transporting dye such as an aluminum trihydroxide complex is mixed with an ink obtained by: the phosphor powder doped with copper or the like in zinc sulfide may be dissolved in a binder of a ferroelectric such as cyanoethyl cellulose, cyanoethyl sucrose, cyanoethyl プルラン, or if necessary, a ferroelectric ceramic powder such as barium titanate may be dissolved in a polar solution such as acetonitrile.

In forming the pattern portion and the base portion of the display portion 2 and the opaque colored layer 11, a common transparent or opaque ink is preferably formed by a method such as screen printing, ink jet printing, thermal transfer printing, gravure printing, spray coating, dip coating, spin coating, or vapor deposition. In addition, the original color of the printing substrate may be used.

The printed film before the deep drawing is subjected to deep drawing by a method such as pressing, vacuum forming, or press forming to form a desired shape along the key top 3, thereby forming a shaped film having a concave portion provided with the key top body 16. In this case, in order to prevent the resistance values of the transparent electrode 10 and the base electrode 14 from increasing, it is necessary to ensure sufficient roundness of the bent portion of the transparent electrode 10.

Next, a thermosetting resin is injected into the concave portion of the shaped film obtained by the deep drawing process, and the shaped film is cured in a mold. Then, the tip of the pressing projection 8 of the key top 3 is coated with conductive ink to form the movable contact 7, thereby completing the member for a push switch according to embodiment 1.

The base, the colored layer, the light-emitting layer 13, and the like are formed by a method such as usual screen printing, ink jet printing, thermal transfer printing, gravure printing, spray coating, dip coating, spin coating, or vapor deposition.

The transparent insulating film 9 is sealed by adding a soft resin and an elastic plastic to a binder and further adding a dye or a pigment to the transparent colored layer 15 and the opaque colored layer 14, and the same resin material is preferably used for the purpose of having the same stretchability. Although the thickness is 1 to 20 μm, it is easy to set it to 3 μm or more for printing or the like, and it is easy to form it when the total thickness is small, preferably 10 μm or less.

The shape of the key top can be formed by a common method such as blow molding, vacuum forming, or mold forming. In order to prevent the appearance of the display section 2 from deviating from a specific position, it is preferable to mold the transparent insulating film 9 to a thermal deformation temperature except for a portion having the display section 2, and after keeping the shape along the mold, the shape can be accurately obtained by cooling the film before removing the pressure. Since the resistance value of the conductor is increased more easily as the drawing speed is higher, the drawing speed is preferably 100 mm/min or less, more preferably 50 mm/min or less.

The material to be filled in the key top main body 16 forming the plunger (プランジヤ) portion and the like can be selected from a hard or soft resin and an elastic plastic. However, the material is not limited to thermoplastic, thermosetting, plate-like, liquid, etc., and a liquid thermosetting resin which facilitates the injection operation is preferable. The molding may be performed by injection molding, transfer molding, potting, or the like, or may be performed by adhesion to a molded article.

Next, various forms of the display unit 2 will be described.

The display part 2 is composed of a pattern part of characters, symbols and patterns from its base part, at least one of which is self-luminous, and the self-luminous part is composed of a light-emitting layer 13 sandwiched between a pair of either one of transparent electrodes 10 and a base electrode 14.

Characters, symbols, and patterns constituting the pattern portion of the display portion 2 can be obtained by a general printing method, and various designs can be conceived by different combinations of transmitted light, self-luminescence, reflected light, and chromatic aberration due to the relation to the background of the display portion 2.

Fig. 2 to 11 are sectional views of main portions of the display portion with different designs. Among these, fig. 2 to 8 illustrate the case of the display portion pattern in which characters, symbols, patterns, and the like emit light, and fig. 8 to 10 illustrate the case of the display portion pattern in which the base portion emits light.

In the 1 st form of the display unit 2 shown in fig. 2, the transparent insulating film 9, the transparent electrode 10, the opaque colored layer 11 having the protruding stamper 12, the light-emitting layer 13 filling the protruding stamper 12, and the base electrode 14 are arranged from top to bottom, and the configuration is the same as that of the embodiment 1 shown in fig. 1.

In the 2 nd embodiment of the display unit 2 shown in fig. 3, from top to bottom, the transparent insulating film 9, the opaque colored layer 11 constituting the base portion having the protruding die 12, the transparent colored layer 15 constituting the pattern portion filling the protruding die 12, the transparent electrode 10, the light-emitting layer 13, and the base electrode 14 are provided.

In the 3 rd form of the display part 2 shown in fig. 4, from top to bottom, a transparent insulating film 9, an opaque colored layer 11 constituting a base part having a protruding stamp part 12, a colored transparent electrode 10a constituting a pattern part inserted into the protruding stamp part 12, a light-emitting layer 13 filling the stamp part 12 with the colored transparent electrode 10a, and a base electrode 14 are provided.

In the 4 th form of the display part 2 shown in fig. 5, from top to bottom, there are a transparent insulating film 9, a transparent electrode 10, an opaque colored layer 11 constituting a base part having a protruding stamp part 12, a transparent colored layer 15 constituting a pattern part filling the protruding stamp part 12, a light-emitting layer 13, and a base electrode 14.

In the 5 th form of the display unit 2 shown in fig. 6, the overcoat layer 16, the opaque colored layer 11 constituting the base portion of the protruding die portion 12 (the die portion 12 is filled with the overcoat layer 16), the transparent colored layer 15 constituting the pattern portion, the transparent insulating film 9, the transparent electrode 10, the light-emitting layer 13, and the base electrode 14 are provided from top to bottom.

In the 6 th form of the display part 2 shown in fig. 7, from top to bottom, the transparent insulating film 9, the transparent electrode 10, the opaque colored layer 11 constituting the pattern part, the transparent colored layer 15 constituting the base part, the light-emitting layer 13, and the base electrode 14 are provided.

In the 7 th form of the display unit 2 shown in fig. 8, the transparent insulating film 9, the transparent electrode 10, the light-emitting layer 13 constituting the pattern unit, the colored conductive layer 18a, and the base electrode 14 are provided from the top to the bottom.

In the 8 th form of the display unit 2 shown in fig. 9, from top to bottom, there are a transparent insulating film 9, a transparent electrode 10, an opaque colored layer 11 constituting a pattern portion, a transparent colored layer 15 constituting a base portion covering the periphery of the opaque colored layer 11, a light-emitting layer 13, and a base electrode 14.

In the 9 th form of the display unit 2 shown in fig. 10, from top to bottom, there are a transparent insulating film 9, an opaque colored layer 11 constituting a pattern portion, a transparent colored layer 15 constituting a base portion, a transparent electrode 10 covering the peripheries of the opaque colored layer 11 and the transparent colored layer 15, a light-emitting layer 13, and a base electrode 14.

In the 10 th form of the display unit 2 shown in fig. 11, from top to bottom, there are a transparent insulating film 9, an opaque colored layer 11 constituting a pattern portion, a colored transparent electrode 10a covering the periphery of the opaque colored layer 11, a light-emitting layer 13, and a base electrode 14.

In the case shown in fig. 4 and 11, the colored transparent electrode 10a is formed by coloring the transparent electrode 10, and the transparent colored layer 15 is not used, so that the processing process is simplified and the processing cost is reduced.

Also, in the case shown in fig. 8, the characters, symbols and patterns required by the light emitting body 13 can be formed by omitting the printing of the opaque coloring layer, thereby reducing the number of printing, simplifying the manufacturing process and reducing the manufacturing cost.

The transparent colored layer 15 and the opaque colored layer 11 are made of a mixture of a soft resin and an elastic plastic, and a dye and a pigment, and are sealed with the transparent insulating film 9, and a material having good extensibility is used in the same manner, so that it is preferable to use a resin as the transparent insulating film 9.

Embodiment 2 of the invention

The member for a push switch of the present embodiment is the same as that of embodiment 1 except that a conductive body for connecting the transparent electrode and the base electrode is provided. The layer structure shown in detail in fig. 3 and in fig. 12 will be described in detail with respect to the structure near the upper surface of the key top according to the present embodiment.

The transparent insulating film 9 is provided with an opaque colored layer 11 as a concealing layer and a transparent colored layer 15 of the display unit 2. Next, an anchor undercoat layer 17 is provided to improve the sealing of the transparent electrode 10. This anchor undercoat layer 17 may be omitted in the case of having the same function as the transparent coloring layer 15. In order to avoid making the transparent electrode 10 too large and to maintain insulation from the base electrode 14, it is critical that the conductor 14d not connected to the base electrode 14 overlap. The light-emitting layer 13 and the conductor layer 18b must be formed to cover the transparent electrode 10 and the main portion of the base electrode 14 and the transparent electrode 10, and also to cover the transparent electrode 10, in order to ensure insulation between the base electrode 14 and the transparent electrode 10. The base electrode 14 is covered with an insulating film layer 19. Thus, the base electrode 14 keeps the insulation between the base electrode 14 and the transparent electrode 10, and the base electrode 14 restricts the flow of the material of the conductor 14d constituting the base electrode 14 that softens and flows when the molding is expanded and contracted, thereby achieving the effect of suppressing the increase in the resistance value of the base electrode 14.

High electric conductors such as barium titanate and potassium titanate are added to the binder of the conductor layer 18b, whereby the electric power can be increased. For the insulating transparent electrode 10 and the base electrode 14, the resistivity and the film thickness of the conductor layer 18b are very important, and the resistivity must be 13 times or more and the film thickness must be at least 10 μm or more at the applied DC100V voltage. If such insulation is not achieved, the light emission luminance is lowered and the power is lowered, so that attention must be paid. Of course, there should be no air holes or impurities. When high-concentration ink such as solvent-free ink is used, the film thickness is generated at one time, pores are reduced by solvent volatilization, and the insulation property is simply ensured.

The storage modulus at the molding temperature of the adhesive must not be smaller than the sizes of the substrate and the insulating film layer 19, and must be more fluid and more easily stretched than the above. If viscoelasticity is measured dynamically, it is better to be 1 order of magnitude or 2 orders of magnitude different from its storage modulus of elasticity. When the dynamic viscoelasticity test is not performed using a large amount of test material, the magnitude of change of the test material can be determined by maintaining the test material at a certain test temperature using a microhardness tester.

The upper surface of the key top 3 is not distorted by shaping but hardly extended, and is easily damaged and broken around the upper surface and at the boundary of the layers of material, particularly at the overlapping portion of the conductor 10d connected to the transparent electrode 10 and the conductor connected to the base electrode 14, due to the maximum stretching at the side of the key top, which must be avoided.

Further, in order to prevent breakage due to the falling debris of the molding or increase in resistance, a large number of switching circuits are connected to the transparent electrode 10 and the base electrode 14 as redundant circuits, respectively, which is advantageous in light emission stability.

Fig. 13 is a plan view of a model example having conductors connected to a plurality of base electrodes used in the member for a push switch according to embodiment 2 of the present invention.

The base electrode 14 of the display section 2 corresponding to the plurality of key tops 3 is formed in a substantially circular or elliptical shape of a sufficient size so as to cover the ground of the light emitting layer 13, and two linear conductors 14d extend from the vicinity of each base electrode 14, and these two conductors 14d are finally connected to the trunk 14s via the line 14k and finally connected to the electrodes of the key switch member 1.

Fig. 14 is a plan view of a model example having conductors connected to a plurality of transparent electrodes used in the member for a push switch according to embodiment 2 of the present invention.

The transparent electrodes 10 of the display section 2 corresponding to the plurality of key tops 3 are formed into a substantially circular or elliptical shape of a sufficient size to cover the ground of the light emitting layer 13, and two linear conductors 10d extend from the vicinity of each transparent electrode 10, and these two conductors 10d are finally connected to the trunk 10s via the line 10k and finally connected to the electrodes of the key switch member 1.

As shown in the figure, the outline of the transparent electrode 10 is larger than that of the base electrode 14 by one turn, and when the template of the base electrode 14 and the template of the transparent electrode 10 are overlapped, the situation is shown in FIG. 15. That is, the base electrode 14 covers the transparent electrode 10, but the conductor 14d drawn from the base electrode 14 and the conductor 10d drawn from the transparent electrode do not overlap each other, and the lead line 14k and the trunk line 14s of the base electrode do not overlap the lead line 10k and the trunk line 10s of the transparent electrode.

Thereby, since the conductor 14d connected to the base electrode 14 and the conductor 10d connected to the transparent electrode 10 are unlikely to come into contact to cause damage and breakage, stable illumination light can be surely obtained.

Fig. 16 is an enlarged cross-sectional view showing the structure of the base electrode 14 for the same design as the display section in fig. 12.

As shown in fig. 16, when the base electrode 14 is used as a conductive layer of a composite material and a conductive filler layer 21 composed of a conductive polymer layer 20, an organic polymer and a conductive filler, even if the connection of the conductive filler is broken, the conductivity can be maintained well by the compensation action of the conductive polymer layer 20.

The thickness of the base electrode 14 and the conductor 14d connected thereto is preferably 3 times or more or 5 times or more the size of the conductive filler, since the film becomes thin after molding. The shape of the conductive filler is preferably a granular shape close to a sphere, which must be moved similarly to the deformation in accordance with the flow direction of the adhesive.

In addition to this, fibrous and planar fillers are selected for confirming particle connection, and the fibrous fillers can be oriented in the direction according to the flow direction, and the resistance value can be easily maintained, which is very suitable. The aspect ratio of the fibrous conductive filler is preferably 10 or more, or 20 or more, more preferably 50 or more. The length is preferably 0.1 mm from the point of printability. Although carbon-coated or silver-plated ceramic whiskers such as polyacrylonitrile fibers, etc., which are broken carbon fibers, zinc oxide, potassium titanate, etc., can be used, a material having a soft texture is more preferable, and a material such as acryl, rayon, polyester, phenol synthetic fibers, single-walled nanotubes, multi-walled nanotubes, etc., which are subjected to silver plating, and it is very preferable that the nanotubes are conductive fibers having a linear diameter of 0.2 μm or less. The compounding amount is 0.1 to 20 wt% depending on the desired resistance value.

Embodiment 3 of the invention

Fig. 17 shows a member for a push switch according to embodiment 3 of the present invention.

In the member for a push switch according to embodiment 3 of the present invention shown in fig. 17, a display unit 2 composed of characters, symbols, and patterns is provided in the middle of a key top 3, and a surface light emitter 14 which emits light by itself is used in the display unit 2.

In the member 1 for a push switch according to embodiment 3, the fixed contact 6 on the circuit board 5 and the contact thin film member 23 in which the movable contact 7 is provided in the elastically deformable dome-shaped member corresponding to the movable contact 7 are integrally formed, and the middle portion of the dome-shaped portion 22 of the contact thin film member 23 is provided with the key top 3 which can be pressed and contacted by the protrusion 8.

Therefore, the 1 st resin molded body 24 having a desired key top shape is integrally provided on the front surface of the transparent insulating film 9, and the transparent electrode 10 is provided on the rear surface of the transparent insulating film 9.

The transparent coloring layer 15 of the pattern part of the display part 2 made of transparent coloring ink is provided on the back surface of the transparent electrode 10 facing the upper surface of the key top 3. The display unit 2 is formed as a part of the upper surface of the key top 3, and the light-emitting layer 13 made of a light-emitting material is provided on the back surface of the transparent colored layer 15 and the back surface of the transparent electrode 10 around the transparent colored layer 15. On the back surface of the base electrode 14, a 2 nd resin molded body 25 of the protrusion 8 is integrally formed on the back surface portion of the key top 3.

The materials of the respective portions in embodiment 3 are the same as those in embodiment 1, and the description of embodiment 1 is referred to.

Next, a method for manufacturing the member for push switches 1 according to embodiment 3 will be described.

First, a strip-like transparent electrode 10 having a width substantially equal to the width of the key top 3 is formed at a position corresponding to the key top 3 in the transparent insulating film 9, and a pattern portion of the display portion 2 is formed of a transparent colored ink on the transparent electrode 10. Next, a light emitting material is applied to the transparent electrode 10 and the display portion 2 on the back surface of the key top, thereby forming a light emitting layer 13. Next, except for the light-emitting body 13 at a position corresponding to the middle portion of the back surface of the key top 3, an insulating ink having light-shielding and insulating properties is applied around the light-emitting body layer 13 and the transparent electrode 10 to form an opaque colored layer 11. A base electrode 14 as a counter electrode is printed on the light-emitting layer 13, leaving a printing space for the opaque colored layer. Above the base electrode, a 2 nd resin molded body 25 and a pressing portion 8 located at an inner central portion thereof are integrally formed.

Next, the 1 st resin molded body 24 having a desired key top shape is bonded and fixed to the surface of the position corresponding to the transparent insulating film 9 forming the 2 nd resin molded body 25, thereby completing the member 1 for a push switch.

In embodiment 3, since the light-emitting layer is provided in the middle portion of the key top 3 between the 1 st resin molded body 24 and the 2 nd resin molded body 25, the light-emitting layer 13 is in a state of being isolated from the outside, and the influence of moisture and oxygen elements is not caused, and the light emission performance does not decrease even when the light-emitting layer is used for a long time.

Further, in embodiment 1 or 2, the display portion 2 is provided on the upper surface of the key top 3, whereas in embodiment 3, the display portion 2 is provided in the middle portion of the key top 3, and the display portion 2 is located on the upper surface, the lower surface, or the middle portion of the key top 3, and is not limited to a fixed position as long as it is suitable for integrating the key top 3, and may be determined by the quality of design.

Further, since the transparent electrode 10 is located on the transparent insulating film 9 and the display part 2 is generally located on the top of the key top 3 in the position of the key top 2, the lifetime of the light emitting layer 13 is affected by moisture and oxygen elements, and after the transparent insulating film 9 on which the display part 2 is printed is formed, a molded body made of a transparent insulating resin is adhered to the top or formed by internal molding, and once the display part 2 in the middle of the key top 3 is formed, the opportunities for moisture and oxygen elements to enter from the top and from the bottom are equalized, which is an effective means for extending the lifetime.

In addition, the use area is enlarged when the conventional inorganic EL sheet is used as the light source using the light emitting surface body, and only the display portion at the key top is provided with the light emitting layer for the member for the push switch according to the present invention, and the use area is only 1/5-1/100 of the conventional inorganic EL sheet system, and the power consumption can be reduced in accordance with the ratio thereof.

Examples

Examples 1 to 5 prepared for evaluating embodiments 1 to 3, and comparative examples 1 and 2 prepared as control products will be described below.

Preparatory tests

A printed film before molding of the member 1 for push switches according to the present invention and a preliminary test for determining the performance thereof will be described.

Adjustment of thermoplastic adhesives

Thermoplastic polyesters (product name バイロン, manufactured by Toyo Co., Ltd.) having storage elastic moduli of 1 × 10E6(Pa) and 5 × 10E8(Pa) at 100 ℃ were dissolved in 50% solid content of cellosolve acetate to prepare insulating adhesive solutions (the former is represented by IL and the latter is represented by IH, and the following descriptions are omitted).

Adjustment of silver paint (ギンペ - スト)

In IL, granular silver powders (manufactured by Fuda Metal foil powder industries, Ltd., product names silver paint (シルコ - ト) and silver powder (シルバ - パ - ウダ -made by DMC Square (デイ - エムシ - スクウエア)) having average particle diameters of 2.5 μm and 0.3 μm were mixed and dispersed in a desired amount, i.e., a volume resistivity of 1X 10E-3 to 5X 10E-2, to obtain silver paints (ILSL, ILSS, respectively). The same is added to IH to obtain IHSL and IHSS.

Tensile test

Ten kinds of test materials were prepared using four kinds of silver paints prepared under the above conditions, and these silver paints were printed on a 50 μm thick amorphous polyethylene terephthalate film, dried, and then coated with an insulating adhesive to form a 10 μm thick cover film. The printed matter was punched into a 2 mm wide dumbbell shape, and subjected to a tensile test at a tensile rate of 100 mm/min using a universal tensile machine in an environment of 100 ℃, and a tensile rate and a resistance up to 200% were measured at any time. After the test was completed, the thickness of the silver paint on the test piece was measured.

Table 1 and table 2 show the test results of the above 10 test materials.

TABLE 1

Test Material number	Material 1	Material 2	Material 3	Material 4	Material 5
						Silver paint species	ILSS	ILSL	IHSS	IHSL	ILSS
Initial film thickness (micron)	10	25	10	25	10
						After stretching (micron)	3	9	3	9	3
Kinds of surface materials	IH	IH	IL	IL	Is free of
						Initial resistance (R0) (omega)	2.3	0.7	2.3	0.8	2.1
Resistance after stretching (R) (omega)	193	72	252	161	4225
						R/R0	84	103	110	201	2012

TABLE 2

Test Material number	Material 6	Material 7	Material 8	Material 9	Material 10
						Silver paint species	IHSL	ILSS	ILSL	ILSS	ILSL
Initial film thickness (micron)	25	2	10	5	10
						After stretching (micron)	9	0.8	3	2	3
Kinds of surface materials	Is free of	IH	IH	Is free of	Is free of
						Initial resistance (R0) (omega)	0.7	5.7	2.1	5.5	2.1
Resistance after stretching (R) (omega)	2621	349142	930027	OVER	OVER
						R/R0	3744	61253	44287	∞	∞

As a result of this preliminary test, the materials 5 and 6 without the insulating outer layer showed a significant increase in resistance after the tensile test as compared with the case with the insulating outer layer. Further, the resistance is increased particularly seriously with the materials 7 and 8 having a film thickness of less than 3 times the size of the conductive particles after the tensile test.

Example 1

Example 1 corresponds to embodiment 1.

First, in a solution of poly (3, 4-diethoxythiophene) (デナトロン 4001, trades, inc.) of polyethylene doped with sulfonated polystyrene, multi-walled nanotubes (0.01 μm in linear diameter, 5 μm in average linear length, ハイペリオン) having a solid content of 3% were dispersed using a homogenizer (ホモジナイザ one) to obtain a transparent treatment solution. Next, the treatment liquid was completely applied to one side (100 μm side of polymethyl methacrylate (ア ク リ プ レン, manufactured by mitsubishi レ - ヨン)) of the transparent insulating film 9 by a gravure coater, thereby forming a 1 μm-thick transparent electrode 10. After the treatment, the total light transmittance was 70% (measured in accordance with JIS-K7105) and the surface resistance was 500. omega./□ (measured in accordance with JIS-K6911).

The opaque coloring layer 11 is coated on the base of the entire display part 2 except for the pattern part of the display part 2 and the terminal part of the 2 nd electrode by screen printing using black coloring ink having shielding property and insulating property. By printing inorganic EL powder in which zinc sulfide having a green emission color was dispersed in cyanoethyl cellulose on the base punch portion 12, a 20-micron phosphor layer 13 was provided, and a 10-micron thick excitation reflection layer in which barium titanate was dispersed in cyanoethyl cellulose was further produced. Finally, on the base electrode 14, (ド - デント NH-030A, manufactured by ニホンハンダ (ltd)), an electrode facing the light-emitting layer 13 and a terminal electrode connected thereto are provided on the opaque colored layer 11. And after the printing process is finished, fully drying by using a vacuum drying device to obtain the printed film.

A metal sheet having a diameter of 8 mm for heat insulation is provided on the pattern portion of the display portion 2 by using a die having 12 cavities having a concave surface having a diameter of 12 mm, a depth of 7.8 mm and a bottom surface R50 (mm) and a male die made of an elastic body having a hardness of 90 DEG (Shore A hardness) for profiling by this, and the printed film is formed by cold pressing by heating to 110 ℃ with infrared rays and removing the metal sheet. After the male die was removed, an appropriate amount of 80 ° (shore a hardness) liquid silicone was injected as the key top main body 16 to form a 2 nd male die having a cross-sectional shape shown in fig. 1, and the pressing protrusion 8 was formed on the back surface of the key top main body 16. The push-button switch member 1 (corresponding to embodiment 1) is obtained by forming the movable contact 7 on the push-button projection 8 with silicone ink containing carbon black.

When the electrode terminals of the member 1 for push switch and the electrode terminals on the circuit board are placed in correspondence with each other and an alternating current of 50V or 100Hz is applied to the light-emitting layer 13, the entire display section 2 emits green light with a luminance of 5.2 nits.

Comparative example 1

Comparative example 1 was conducted to evaluate example 1.

Comparative example 1 the same as example 1 was conducted except that the transparent electrode 10 was formed using an ITO ink (manufactured by sumitomo osaka セメント (ltd)) in which transparent ceramic particles were dispersed (no nanotube was present).

If the member for the push switch of comparative example 1 is turned on, 5 portions are not turned on, and the remaining light is not uniform, and it is difficult to determine whether or not the member has been turned on.

Example 2

Example 2 corresponds to embodiment 1.

In example 2, the same conductive polymer as in example 1 was added with red color as the transparent electrode 10. The phosphor layer 13 is composed of white zinc sulfide.

First, a dye made of multiwall nanotubes (0.01 μm in diameter, 5 μm in average length, manufactured by ハイペリオン) having a solid content of 3% and an azo compound having a solid content of 0.1 wt% was added to a solution of poly (3, 4-diethoxythiophene) (デナトロン 4001, manufactured by trades et al) doped with sulfonated polystyrene and dispersed by using a homogenizer to obtain a transparent red treatment solution. Next, the treatment liquid was completely applied to one side (100 μm side of polymethyl methacrylate (ア ク リ プ レン, manufactured by mitsubishi レ - ヨン)) of the transparent insulating film 9 by a gravure coater, thereby forming a red transparent electrode 10 having a thickness of 1 μm. Finally, the above-mentioned conductive polymer solution which is not colored is applied around the pattern portion of the display portion 2 by screen printing.

This step was performed in the same manner as in example 1 to obtain a member 1 for a push switch.

The electrode terminals of the push switch member 1 and the electrode terminals on the circuit board are placed in correspondence with each other, and when an alternating current of 50V or 100Hz is applied to the light emitting layer 13, the display section 2 emits light entirely, and the luminance is 6.0 nit.

Example 3

Example 3 corresponds to embodiment 2.

First, in a solution of polyethylene (3, 4-diethoxythiophene) (デナトロン 4001, trades, inc.) doped with sulfonated polystyrene, multi-walled nanotubes (having a linear diameter of 0.01 μm and an average linear length of 5 μm, manufactured by ハイペリオン) having a solid content of 3% were dispersed using a homogenizer to obtain a transparent treatment solution. Next, the treatment liquid was completely applied to one side (100 μm polymethyl methacrylate (ア ク リ プ レン, manufactured by mitsubishi レ - ヨン)) of the transparent insulating film 9 by a gravure coater, thereby forming a 1 μm-thick transparent electrode 10. After the treatment, the total light transmittance was 70% (measured in accordance with JIS-K7105), and the surface resistance was 500. omega./□ (measured in accordance with JIS-K6911).

The opaque colored layer 11 is coated on the base of the entire display part 2 except for the pattern part of the display part 2 and the terminal part of the 2 nd electrode by screen printing using a black colored ink having concealing and insulating properties. Inorganic EL powder in which zinc sulfide having a green emission color was dispersed in cyanoethyl cellulose was printed on the opening portion of the base portion to produce a 20 μm light-emitting layer 13, and further to produce a 10 μm thick conductive layer 18b in which barium titanate was dispersed in cyanoethyl cellulose. Finally, a terminal electrode is provided on the opaque colored layer 11, which is located on the conductor layer 18b and comes out from the conductor 14d connected to the base electrode 14 by silver paste (ILSS). The conductor 14d connected to the base electrode 14 can be covered by printing using the aforementioned thermoplastic adhesive (IH). After the printing was completed, the film was sufficiently dried by a vacuum drying apparatus to obtain a printed film.

A male mold made of an elastic body having a hardness of 90 ° (shore a hardness) was formed by using a mold having 12 cavities having a diameter of 12 mm, a depth of 7.8 mm, and a concave surface R50 (mm) as a ground, and a metal piece having a diameter of 8 mm was provided in a pattern portion of the display portion 2 for heat insulation, heated to 110 ℃ by infrared rays, and the printed film was formed by cold pressing after removing the metal piece. After the male die was removed, an appropriate amount of 80 ° (shore a hardness) liquid silicone rubber was injected as the key top main body 16 to form a 2 nd male die having a cross-sectional shape shown in fig. 1, and a core protruding portion was formed. The movable contact 7 is formed on the projecting portion 8 with silicone ink containing carbon black, and the member 1 for push switch having a large number of key tops 3 is obtained.

The electrode terminals of the member 1 for push switch and the electrode terminals of the circuit board are placed in correspondence with each other, and an alternating current of 50V and 100Hz is applied to the light emitting layer 13, so that the display portions 2 of the plurality of key tops 3 emit bright green light with a brightness of 6.2 nits.

Example 4

Example 3 corresponds to embodiment 2, as in example 3.

In example 4, the same conductive polymer as in example 3 as the transparent electrode 10 was added with red color. The phosphor layer 13 is composed of white zinc sulfide.

First, a dye made of a multi-walled nanotube (0.01 μm in linear diameter, 5 μm in average linear length, manufactured by ハイペリオン) having a solid content of 3% and an azo compound having a solid content of 0.1 wt% was added to a solution of sulfonated polystyrene-doped polyethylene poly (3, 4-diethoxythiophene) (デナトロン 4001, manufactured by trades), and the mixture was dispersed using a homogenizer to obtain a transparent red treatment liquid.

Next, the treatment liquid was completely applied to one side (100 μm polymethyl methacrylate (ア ク リ プ レン, mitsubishi) side) of the transparent insulating film 9 by a gravure coater, to form a red transparent electrode 10 having a thickness of 1 μm. Finally, the conductive polymer solution that is not colored is applied around the pattern portion of the display portion 2 by screen printing. Finally, the unpigmented conductive polymer solution is applied around the pattern by screen printing. Thereafter, the conductor layer 18b was treated in the same manner as in example 1. Next, the base electrode 14 was formed using a mixed conductive ink in which 20% of multi-walled nanotubes were added to the same conductive polymer as the transparent electrode 10, and a 10 μm thick silver paste (ILSL) was printed thereon. A member 1 for a push switch having a large number of key tops 3 was obtained in the same manner as in example 2.

The electrode terminals of the member 1 for push switch and the electrode terminals on the circuit board were placed in correspondence, and an alternating current of 50V and 100Hz was applied to the light-emitting layer 13, so that the display portions 2 of the plurality of key tops 3 all emitted light, and the luminance was 7.0 nit.

Example 5

Example 5 corresponds to embodiment 3.

In example 5, the transparent insulator film 9 was formed by bonding 15 μm thick ethylene vinyl alcohol copolymer films to two sheets of 100 μm polymethyl methacrylate both surfaces of which were plasma-treated. The base of the display part 2 except for the pattern part of the display part 2 is coated with a green cloth transparent coloring ink by screen printing. A polyaniline solution containing a dopant for benzenesulfonic acid reaction in デンドリマ -one (ジアミノブタン, manufactured by DSM) sulfonate, which is 1/6 moles of the structural unit of polyaniline, and デンドリマ -one (dab (pa)8), which is an acrylonitrile starting material, was subjected to inkjet printing to prepare a pattern portion of the display portion 2 and a terminal electrode connected thereto. Subsequently, a conductive polymer ink in which a polyaniline solution and silver powder (シルコ - ト, manufactured by Futian Metal foil powder industries) having a solid content of 75 wt% were mixed was printed from the periphery of the pattern portion to the terminal portion of the display portion 2 to form a coating layer having a thickness of 5 μm. The transparent electrode 10 had a total light transmittance of 65% (measured in accordance with JIS-K7105) and a surface resistance of 700. omega./□ (measured in accordance with JIS-K6911).

An ink for LEC composed of polyethylene (p-phenylene-2, 6-benzimidazole) and polyethylene oxide and lithium p-xylylene disulfonate was coated on the transparent electrode 10 by injection molding printing as well, to form a light-emitting layer 13 having a thickness of 15 μm. Next, the base electrode 14 of the light-emitting layer 13 and the electrode terminal connected thereto were formed by mixing silver and a conductive polymer, and separating the mixture from the formed layer. And after the printing is finished, fully drying the film by using a vacuum drying device to obtain the printed film.

A master mold having 15 female molds each having a depth of 1.5 mm 3 mm × 5 mm and a flat concave bottom surface and a male mold having a depth of 0.9 mm 2.8 mm × 4.8 mm and a flat convex top surface were used, a metal piece of 2.6 mm × 4.6 mm was provided for heat insulation from the pattern portion of the display portion 2, heated to 110 ℃ with infrared rays, and the metal piece was removed to form a printed film by cold pressing. After the male mold was removed, an epoxy resin containing 10 wt% of an iron component was injected as an oxygen scavenger, and a 2 nd male mold having the same sectional shape as that of fig. 11 was used to form a 2 nd resin molded body and a pressing protrusion 8 located at the center thereof.

Finally, the 1 st resin molded body 19 of the desired key top shape made of acrylic resin was adhered with an acrylic adhesive. The electrode portion of the obtained molded body was covered, dip-coated in a silanol solution using aminosilanol as a catalyst, dried and reacted at 40 ℃, and a silicon oxide layer having a thickness of 2 μm was formed on the surface of the molded body, thereby obtaining a uniform member 1 for a push switch (corresponding to embodiment 2).

The electrode terminals of the member 1 for push switch and the electrode terminals on the circuit board were placed in correspondence, and the 4V dc display section 2 was applied to the light emitting layer 13 to emit light entirely, and the luminance was 6.5 nits.

Comparative example 2

Comparative example 2 was conducted to evaluate example 5.

Comparative example 2 the same as example 3 was repeated except that the transparent electrode 10 was formed of ion cathode vacuum sputtered (ion coated) indium tin oxide.

After the members for the push switches in comparative example 2 were turned on, all of them were not turned on.

Possibility of industrial application

The invention provides a member for a key switch capable of effectively using a function of identifying a key on an input device such as a mobile phone and a PDA, a car audio, a vehicle-mounted computer, an audio, a measuring instrument, and a personal computer, and capable of illuminating in a dark place.

Claims (17)

1. A member for a push switch includes: a key top capable of pressing a movable contact arranged opposite to a fixed contact on a circuit board in a direction of contacting with the fixed contact; and a cover base material for mounting the key top at a specific position on the circuit board, and further having a surface light emitter which is integrated with the display part for displaying the key function at the key top, characterized in that: the surface light emitter comprises a light emitting layer provided between a base electrode and a transparent electrode facing the base electrode, the transparent electrode being provided so as to be connected to the display section and being continuously and integrally provided from a side surface to a top surface of the key top, and a multi-walled nanotube containing poly (ethylenediethoxythiophene) and 0.1 to 20 wt% of the poly (ethylenediethoxythiophene), the multi-walled nanotube having a wire diameter of 0.2 μm or less, an aspect ratio of 10 or more, and a wire length of 0.1 mm or less, wherein a ductile electric conductor is connected to the base electrode and the transparent electrode, and a part of the electric conductor corresponding to the side surface of the key top, at least a part of which is subjected to a tensile force during molding, is covered with a polymethyl methacrylate film having a thickness of 25 to 500 μm.

2. The member for a push button switch according to claim 1, wherein: the surface resistance of the transparent electrode is 10 omega/□ or more, and the light transmittance is 90% or less.

3. The member for a push button switch according to claim 1 or 2, characterized in that: the transparent electrode contains conductive fibers having a linear diameter of 0.5 μm or less and an aspect ratio of 20 or more.

4. The member for a push button switch according to claim 1, wherein: the transparent electrode is colored.

5. The member for a push button switch according to claim 1, wherein: the transparent conductive polymer is composed of a derivative of any one of polypyrrole, polythiophene, and polyaniline.

6. The member for a push button switch according to claim 1, wherein: the conductor connected to the base electrode and the conductor connected to the transparent electrode are arranged so as not to overlap in plan view.

7. The member for a push button switch according to claim 1, wherein: the storage elastic modulus corresponding to the molding temperature of the insulating film material is larger than the storage elastic modulus corresponding to the molding temperature of the conductor connected to the base electrode and the conductor connected to the transparent electrode.

8. The member for a push button switch according to claim 1, wherein: the base electrode and the conductor connected to the base electrode are composed of a conductive layer containing an organic polymer and a conductive filler, and the length of at least one side of the conductive filler is 1/3 or less of the thickness of the conductive layer.

9. The member for a key switch according to claim 8, wherein: a conductive polymer layer is added on the conductive layer.

10. The member for a key switch according to claim 8, wherein: the conductive filler is a fibrous material having a wire diameter of 1 μm or less.

11. The member for a push button switch according to claim 1, wherein: the base electrode and the conductor connected to the base electrode are made of a conductive polymer.

12. The member for a push button switch according to claim 1, wherein: the key top has a key top body formed in a desired key top shape on the back surface of the base electrode, and the key top body has a pressing protrusion on the back surface thereof for bringing the movable contact into contact with the fixed contact.

13. The member for a push button switch according to claim 1, wherein: the key top has a 1 st resin molded body and a 2 nd resin molded body, the 1 st resin molded body is formed on the surface of the transparent electrode in a transparent state, a transparent insulating film is interposed between the transparent insulating film and the transparent electrode, and the 2 nd resin molded body is formed on the back surface of the base electrode with a pressing projection capable of bringing the movable contact into contact with the fixed contact.

14. The member for a push button switch according to claim 1, wherein: the cover base material is integrally formed with a plurality of key tops, and a plurality of switch circuits each including the base electrode and the transparent electrode corresponding to the key tops.

15. A method for manufacturing a member for a push switch, wherein the member for a push switch comprises: a key top capable of pressing a movable contact arranged opposite to a fixed contact on a circuit board in a direction of contacting with the fixed contact; and a cover base material for mounting the key top at a specific position on the circuit board, and further comprising a surface light emitter provided integrally with a display unit for displaying a key function at the key top, wherein the surface light emitter comprises a light emitter layer provided between a base electrode and a transparent electrode facing the base electrode, the transparent electrode connected to the display unit and provided integrally continuously from a side surface to a top surface of the key top, and the transparent electrode comprises a transparent conductive polymer composed of a derivative of any one of polypyrrole, polythiophene and polyaniline, and the cover base material is characterized in that: when a member having the transparent electrode formed on one surface of a transparent insulating film is subjected to a deep drawing process to form a desired shape of a key top, the transparent conductive polymer having ductility is used for the transparent electrode at a portion corresponding to a side surface of the key top to which a tensile force is applied at least in the deep drawing process.

16. The method of manufacturing a member for a push button switch according to claim 15, characterized in that: at least before deep drawing, the transparent electrode is formed to have a suitable thickness at a portion corresponding to the side surface of the key top.

17. A method for manufacturing a member for a push switch, wherein the member for a push switch comprises: a key top capable of pressing a movable contact arranged opposite to a fixed contact on a circuit board in a direction of contacting with the fixed contact; and a cover base material for mounting the key top at a specific position on the circuit board, and further comprising a surface light emitter provided integrally with a display unit for displaying a key function at the key top, wherein the surface light emitter comprises a light emitter layer provided between a base electrode and a transparent electrode facing the base electrode, the transparent electrode connected to the display unit and provided integrally and continuously from a side surface to a top surface of the key top, and the transparent electrode comprises a transparent conductive polymer composed of a derivative of any one of polypyrrole, polythiophene and polyaniline, and the cover base material comprises: a step of forming a printed film before deep drawing, in which the transparent electrode is formed at a position corresponding to the key top on one surface of a transparent insulating film covering the outer surface of the key top, a luminescent layer formed of the surface light emitter is formed on the transparent electrode, the base electrode is formed on the luminescent layer, and a conductor having ductility and connected to the base electrode and the transparent electrode is formed; and a step of forming a desired key top shape by subjecting the printed film to a deep drawing process, wherein an extension of a part of the conductor to which a tensile force acts during the deep drawing process is covered with an insulating film.